UAMS Department of Neurobiology and Developmental Sciences - Bones of the Body

Gross Anatomy


Bones of the Body - Organized by Region

Copyright 2009, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences



Back Thorax Abdomen Pelvis and Perineum Upper Limb Lower Limb Head and Neck


Bones of the Back Region - Listed in Superior to Inferior Order

Bone Structure Description Notes

occipital

the bone forming the posterior surface of the skull it articulates superolaterally with the parietal bones through the lambdoid suture, anteroinferiorly with the temporal bone and anteriorly with the body of the sphenoid bone
external occipital protuberance a low process on the external surface of the occipital bone in the midline it is an attachment site for the ligamentum nuchae; the superior nuchal lines of the two sides meet in the midline at the external occipital protuberance; also known as: inion
inferior nuchal line a low ridge that runs transversely on the external surface of the squamous part of the occipital bone inferior to the superior nuchal line it is an attachment site for deep neck muscles
superior nuchal line a low ridge that runs transversely on the external surface of the squamous part of the occipital bone it is an attachment site the for the trapezius and splenius mm.
occipital condyle a low, wide projection from the inferior surface of the lateral part of the occipital bone paired; it articulates with the atlas
vertebra one of a series of irregular bones that form the spine a vertebra has two parts: the vertebral body and the vertebral arch; there are 33 vertebrae total: 7 cervical, 12 thoracic, 5 lumbar, 5 fused to form the sacrum, 4 coccygeal; features of a typical vertebra include: body, pedicles, transverse processes, laminae, articular processes, spinous process
vertebral body the largest part of the vertebra it is shaped like a short cylinder; adjacent vertebral bodies articulate through a symphysis
vertebral arch the ring of bone formed by the paired pedicles and paired laminae of the vertebra the transverse processes and spinous process are attached to the neural arch; the neural arch protects the spinal cord
pedicle short strong process that extends posteriorly from the posterolateral surface of the vertebral body paired; it connects the body with the transverse process; it is marked by superior & inferior vertebral notches;
transverse process a lateral process the extends from the junction of the pedicle and the lamina of the vertebra a site for muscle attachment and rib articulation
lamina a broad flat plate of bone located between the transverse process and the spinous process of the vertebra paired; it is flattened markedly in the anteroposterior direction; ligamenta flava span the interval between the laminae of adjacent vertebrae
articular processes processes that project inferiorly and superiorly from the junction of the lamina and pedicle of the vertebra two pair on each vertebra (superior and inferior); the superior articular processes of one vertebra articulate with the inferior processes of the adjacent vertebra through synovial joints
intervertebral notch a notch on the superior and inferior surface of the vertebral pedicle the superior intervertebral notch of one vertebra combined with the inferior intervertebral notch of the adjacent vertebra forms the intervertebral foramen
intervertebral foramen an opening between the pedicles of adjacent vertebrae adjacent intervertebral notches form the intervertebral foramen; an opening for passage of the spinal nerve
vertebral canal the opening formed by the combination of the body and the vertebral arch it contains the spinal cord, meninges, epidural fat and the internal vertebral plexus of veins
spinous process a posterior midline process arising from the junction of the two laminae of the vertebra it projects inferiorly; it is an important site of muscle attachment; spinous processes of cervical vertebra 2-6 are bifid
cervical vertebrae   the seven vertebrae of the neck cervical vertebrae have the features of the typical vertebra plus all have transverse foramina (for passage of the vertebral artery); C2-C6 have bifid spinous processes; cervical vertebrae have relatively small bodies; several cervical vertebra are named: atlas, axis, vertebra prominens
atlas (C1) the first cervical vertebra

it is called atlas in comparison the mythological Greek Titan Atlas, who bore the weight of the world on his shoulders; it has no vertebral body, only anterior & posterior arches; it articulates with the odontoid process of the axis

axis (C2) the second cervical vertebra the odontoid process (dens) projects superiorly from its body; it articulates with the anterior arch of the atlas
vertebra prominens the seventh cervical vertebra it has a long, non-bifid spinous process which is prominent at the nape of the neck, hence its name
thoracic vertebrae   the 12 vertebrae associated with the thoracic region thoracic vertebrae have the features of a typical vertebra plus they are characterized by long slender spines that project inferiorly; they have facets for articulation with ribs; thoracic vertebrae have bodies of intermediate size
costal articular facet on the body small smooth areas at the junction of the body and the vertebral arch most thoracic vertebrae have 2 costal facets on each side (one superior and one inferior); the superior costal facet of one vertebra and the inferior costal facet of the adjacent vertebra both articulate with the head of the same rib; also known as demifacets
costal articular facet on the transverse process a small smooth area on the transverse process of the thoracic vertebra it articulates with the articular facet on the tubercle of the rib
lumbar vertebrae   the 5 vertebrae located in the lumbar region lumbar vertebrae have the features of a typical vertebra plus they are characterized by short, blunt spines that project posteriorly; lumbar spines do not overlap making the lumbar level a good one for spinal tap; lumbar vertebrae are built strong and have the largest bodies of all vertebrae
sacrum   a triangular bone that is the posterior skeletal element forming the pelvis it is formed by 5 fused vertebrae; the sacrum and two os coxae bones form the pelvis
anterior sacral foramina an opening in the anterior surface of the sacrum there are four pairs; each transmits the ventral primary ramus of the respective sacral spinal nerve; branches of the lateral sacral aa. enter the sacral canal through these openings
posterior sacral foramina an opening in the posterior surface of the sacrum there are four pairs; each transmits the dorsal primary ramus of the respective sacral spinal nerve
promontory a projection of the superior part of the sacrum in an anterior direction the body of the fifth lumbar vertebra sits on the sacral promontory and articulates with it through a symphysis
sacral canal the opening in the center of the sacrum it is the continuation of the vertebral canal at sacral vertebral levels
articular surface the roughened area located on the lateral surface of the sacrum this surface articulates with the ilium in the sacroiliac articulation
body the central portion of the sacrum the body is equivalent to the bodies of the other vertebra
base the superior surface of the sacrum the base of the sacrum articulates with the fifth lumbar vertebra through an intervertebral disk
sacral hiatus an opening in the posterior surface of the sacrum in the midline it is a normal feature that results from the failure of fusion of the laminae of the fifth sacral segment (and sometimes the fourth) during development
ala the lateral portion of the sacrum paired; it projects laterally from the body of the sacrum; it represents the fused costal and transverse processes of the first sacral vertebra
coccyx   the most inferior portion of the vertebral column the coccyx results from the fusion of the four coccygeal vertebrae; it may be a single bone or the first coccygeal vertebra may be separated from the other three; it articulates with the fifth sacral segment; coccygeal vertebrae are reduced in complexity, having no pedicles, laminae or spines

Bones of the Upper Limb - Listed in Proximal to Distal Order

Bone Structure Description Notes
clavicle   an "S" shaped bone located between the sternum and the scapula it articulates medially with the manubrium of the sternum and laterally with the acromion process of the scapula; it forms a strut that supports the upper limb; it is frequently fractured; it is the first bone to begin ossification during development
  sternal extremity the thickened proximal end of the clavicle it is triangular in cross-section; it articulates with the clavicular notch of the sternum through a synovial joint with two joint cavities separated by an articular disk; the sternoclavicular joint has the action of a ball and socket joint, but not the physical shape of one
  acromial extremity the flattened lateral end of the clavicle it is marked on its inferior surface at the junction of the medial 2/3 and the lateral 1/3 by a roughened area for attachment of the coracoclavicular ligament; it articulates with the coracoid process of the scapula through a syndesmosis; it articulates with the acromion process of the scapula through a synovial joint; due to the shape of the distal clavicle, the acromion process passes inferior to the clavicle in acromioclavicular dislocations
scapula   the bone of the shoulder the scapula floats in a sea of muscles, so it is difficult to fracture; it articulates with only one bone - the clavicle at the coracoclavicular and acromioclavicular joints
superior border the superior edge of the scapula the superior border of the scapula is marked by the scapular notch laterally
medial border the border of the scapula that runs from the superior angle to the inferior angle it is an important site of muscle attachments for the intermediate layer of back muscles
superior angle the angle of the scapula formed at the union of the superior and medial borders it is the attachment site for the levator scapulae m.
lateral border the portion of the scapula that runs inferomedially from the infraglenoid tubercle to the inferior angle it is an important site of muscle attachments for the teres major m., teres minor m. and the long head of the triceps brachii m.; it has a groove for passage of the circumflex scapular a.
inferior angle the angle of the scapula formed by the union of the medial and lateral borders the inferior angle of the scapula often has a slip of origin of the latissimus dorsi attached to it
glenoid cavity the articular surface located at the junction of the superior and lateral borders of the scapula it articulates with the head of the humerus; it is deepened by a fibrocartilaginous rim called the glenoid labrum
supraglenoid tubercle a projection of bone located superior to the glenoid cavity it is the attachment site for the tendon of the long head of the biceps brachii m.
infraglenoid tubercle a projection of bone located inferior to the glenoid cavity it is the attachment site of the tendon o of the long head of the triceps brachii m.
spine a heavy ridge that runs from the medial border of the scapula to the acromion process it supports the acromion process; it divides the posterior surface of the scapula into a supraspinatous fossa and an infraspinatous fossa
scapular notch a notch on the superior border of the scapula located medial to the attachment of the coracoid process it is bridged by the superior transverse scapular ligament; the suprascapular a. passes superior to the superior transverse scapular ligament and the suprascapular n. passes inferior to it (Army goes over the bridge, Navy goes under the bridge)
coracoid process a beak-like process that projects anteriorly from the lateral end of the superior border of the scapula it is the attachment site for the short head of the biceps brachii m., the coracobrachialis m., the pectoralis minor m. and the coracoacromial and coracoclavicular ligaments
acromion a broad, flat process located at the lateral end of the scapular spine it articulates with the clavicle through a synovial joint (acromioclavicular joint)
supraspinatous fossa a broad depression located superior to the spine of the scapula it is the site of origin of the supraspinatus m.
infraspinatous fossa a broad depression located inferior to the spine of the scapula it is the site of origin of the infraspinatus m.
humerus   the bone of the arm (brachium) the humerus articulates proximally with the scapula at the glenoid fossa; it articulates distally with the radius and ulna at the elbow joint
head the smooth, rounded proximal end of the ulna it articulates with the glenoid cavity of the scapula to form the shoulder joint
anatomical neck the constricted region located inferolateral to the head it is located at the circumference of the smooth articular surface of the head
surgical neck the proximal part of the shaft of the humerus it is located inferior to the greater and lesser tubercles; it is a site of frequent fracture; fractures of the surgical neck of the humerus endanger the axillary n. and the posterior circumflex humeral a.
greater tubercle the large projection located lateral to the head of the humerus it is the attachment site of the supraspinatus, infraspinatus & teres minor mm.
lesser tubercle the projection located lateral to the head of the humerus on the anterior surface it is the insertion site of the subscapularis m.
intertubercular groove the groove on the anterior surface of the humerus that is located between the crest of the greater tubercle and the crest of the lesser tubercle it is occupied by the tendon of the long head of the biceps brachii m.; the transverse humeral ligament spans the intertubercular groove and holds the biceps tendon in place; it is the attachment site for the tendon of the pectoralis major (lateral lip), teres major (medial lip), and latissimus dorsi (floor)
crest of the greater tubercle the ridge of bone on the anterior surface of the humerus extending inferiorly from the greater tubercle it forms the lateral lip of the intertubercular groove; it is the attachment site for the transverse humeral ligament and the pectoralis major m.
crest of the lesser tubercle the ridge of bone on the anterior surface of the humerus extending inferiorly from the lesser tubercle it forms the medial lip of the intertubercular groove; it is the attachment site for the transverse humeral ligament and the teres major m.
deltoid tuberosity the roughened process on the lateral surface of the mid-shaft of the humerus it is the insertion site of the deltoid m.
radial groove the groove that spirals around the posterior surface of the shaft of the humerus it is a depression for the radial n. and the deep brachial vessels; fracture of the humerus at mid-shaft can injure the radial nerve and deep brachial vessels because they are in contact with bone at this location
medial supracondylar ridge a narrow ridge running proximally from the medial epicondyle of the humerus the pronator teres m. takes origin from the common flexor tendon near the most inferior part of the medial supracondylar ridge
lateral supracondylar ridge a narrow ridge running proximally from the lateral epicondyle of the humerus it is the site of origin of the brachioradialis m. and the extensor carpi radialis longus m.
lateral epicondyle a knob-like projection on the lateral side of the humerus proximal to the capitulum it is the site of attachment of the common extensor tendon which is the origin of several forearm extensor muscles (extensor carpi radialis brevis m., extensor digitorum m., extensor digiti minimi m., extensor carpi ulnaris m. and supinator m.); inflammation of the attachment of the common extensor tendon is called lateral epicondylitis which is also known as "tennis elbow"
medial epicondyle a knob-like projection on the medial side of the humerus proximal to the trochlea it is the attachment site of the common flexor tendon which is the origin for the superficial group of forearm flexor muscles (pronator teres m., flexor carpi radialis m., palmaris longus m., flexor carpi ulnaris m. and flexor digitorum superficialis m.); inflammation of the attachment of the common flexor tendon is called medial epicondylitis which is also known as "tennis elbow"; the ulnar nerve is in contact with bone as it courses posterior to the medial epicondyle where it is susceptible to injury from blunt trauma or fracture
coronoid fossa the depression on the anterior surface of the humerus located proximal to the trochlea near the elbow it accommodates the coronoid process of ulna when the elbow is flexed
radial fossa the depression on the anterior surface of the humerus located proximal to the capitulum near the elbow it accommodates the head of the radius when the elbow is flexed
olecranon fossa the depression on the posterior surface of the humerus located just proximal to the elbow it accommodates the olecranon process of the ulna when the elbow is extended
capitulum the rounded process that caps the distal end of the lateral condyle of the humerus it articulates with the head of the radius; capitulum means "little head"
trochlea the grooved process that caps the distal end of the medial condyle of the humerus it articulates with the trochlear notch of the ulna; the shape of the trochlea and the trochlear notch limits side-to-side movement and guarantees a hinge action; trochlea means "pulley"
ulna   the bone on the medial side of the forearm (antebrachium) the ulna articulates proximally with the trochlea of the humerus and the head of the radius; it articulates distally with the ulnar notch of the radius
olecranon the proximal end of the ulna it is the insertion site of the tendon of the triceps brachii m.; when the elbow is extended, the olecranon of the ulna engages the olecranon fossa of the humerus
trochlear notch the crescent shaped notch on the anterior surface of the proximal end of the ulna it is located between the olecranon and the coronoid process; it articulates with the trochlea of the humerus; a ridge within the trochlear notch fits into the groove in the trochlea of the ulna which limits side-to-side movement and guarantees a hinge action
coronoid process the anterior projection of bone located distal to the trochlear notch it is the insertion site of the brachialis m.
radial notch the notch on the lateral surface of the humerus located just distal to the trochlear notch it accommodates the head of the radius; the annular ligament of the radius attaches to the anterior and posterior edges of the radial notch of the ulna to encircle the head of the radius
body the long slender midportion of the ulna it is also called the shaft or diaphysis; the interosseous membrane attaches to the entire length of the interosseous border of the body of the ulna
head the distal end of the ulna it is small and rounded for articulation with the radius
styloid process a small projection from the distal surface of the head of the ulna it is the site of attachment of the articular disk of the distal radioulnar joint
radius   the bone on the lateral side of the forearm (antebrachium) the radius pivots on its long axis and crosses the ulna during pronation
head the rounded proximal end of the radius it has a smooth, rounded surface for articulation with the ulna; the head of the radius is encircled by the annular ligament (4/5 of a circle) and the radial notch of the ulna (1/5 of a circle)
neck the constricted area of the radius located distal to the head the annular ligament of the radius surrounds the head of the radius, not the neck of the radius
radial tuberosity a roughened area on the anteromedial surface of the radius located just distal to the neck it is the insertion site of the tendon of the biceps brachii m.
body the long, slender midportion of the radius it is also known as the shaft or diaphysis; the interosseous membrane attaches to the entire length of the body of the radius along its interosseous border; a fracture of the distal end of the body of the radius with a dorsal displacement of the distal fragment is quite common and is called a Colles' fracture
ulnar notch a shallow notch located on the medial surface of the distal end of the radius it articulates with the head of the ulna
styloid process the distal-most projection from the lateral side of the radius the radial styloid process projects lateral to the proximal row of carpal bones
carpal bones   the bones of the wrist eight bones arranged in two rows; a pneumonic for memorizing the carpal bones is " some lovers try positions that they can't handle" - the first letters of these eight words are the first letters of the names of the eight carpal bones arranged from lateral to medial, proximal row first: scaphoid, lunate, triquitrum, pisiform/trapezium, trapezoid, capitate, hamate
proximal row lateral to medial: scaphoid, lunate, triquetrum, pisiform the scaphoid and lunate bones of the proximal row articulate with the distal end of the radius
distal row lateral to medial: trapezium, trapezoid, capitate, hamate the distal row of carpal bones articulates with the metacarpal bones of the hand
scaphoid   the most lateral carpal bone of the proximal row the scaphoid bone is located in the floor of the anatomical snuff box; it is frequently fractured by hyperextension and abduction of the wrist; scaphoid means "boat-shaped"
lunate   the carpal bone located between the scaphoid and triquetrum in the proximal row the lunate is so named because it is "moon-shaped" (crescent shaped) in longitudinal section; the head of the capitate sits within the crescent of the lunate
triquetrum   the most medial bone in the proximal row of carpal bones it articulates with the pisiform which sits anterior to it
pisiform   a sesamoid bone in the tendon of the flexor carpi ulnaris m. it articulates with the triquetrum; the pisiform bone provides a protective function for the flexor carpi ulnaris tendon by bearing the forces generated by the tendon riding across the triquitrum, especially during wrist extension; pisiform means "pea-shaped"
trapezium   the most lateral carpal bone of the distal row it forms a saddle joint with the metacarpal bone of the thumb; "the thumb swings on the trapezium"
trapezoid   the carpal bone located between the trapezium and the capitate in the distal row the trapezoid is named for its trapezoid shape
capitate   the carpal bone located between the trapezoid and the hamate in the distal carpal row the capitate is the largest carpal bone; it is named for its rounded head; forces generated in the hand (as during a punching blow with the fist) are transmitted through the third metacarpal bone to the capitate and proximally through the lunate to the radius
hamate   the most medial carpal bone in the distal row the hamulus (hook) of the hamate is its distinguishing characteristic; it is an attachment point of the flexor retinaculum
metacarpal bones   the bones located between the carpal bones and the phalanges of the hand there are a total of five metacarpal bones in the hand; the metacarpals of the four fingers are bound together by ligaments to form a firm foundation for finger movements; the metacarpal of the thumb is more independent in its range of motion
base the proximal end of the metacarpal it articulates with the distal row of carpal bones
body the slender shaft of the metacarpal it is also known as the diaphysis
head the rounded distal end of the metacarpal it articulates with the proximal phalanx of the corresponding digit
phalanx (phalanges)   the distal two or three bones in the digits of the hand there are a total of 14 phalanges in the hand; the thumb has two phalanges (proximal and distal) and each finger has three phalanges (proximal, middle and distal); phalanx means "line of soldiers"
base the proximal end of the phalanx the base of the proximal phalanx articulates with the head of the corresponding metacarpal bone; the base of the middle or distal phalanx articulates with the head of the next most proximal phalanx
body the slender shaft of the phalanx also known as the diaphysis; the body of the distal phalanx is very short
head the distal end of the phalanx the proximal, middle and distal phalanges each have a head; the head of a proximal or middle phalanx articulates with the base of the next most distal phalanx

Bones and Cartilages of the Head and Neck - Listed Alphabetically

Bone/Cartilage Structure Description Notes
arytenoid cartilage a pyramid shaped cartilage located on the superior margin of the cricoid lamina paired; each is connected to the epiglottis above via the aryepiglottic m. and to the thyroid cartilage anteriorly via the vocal ligament; paired arytenoid cartilages are pulled together (adducted) by the arytenoid m.
corniculate cartilage a small cartilage located on the apex of the arytenoid cartilage corniculate cartilage is found in the base of the aryepiglottic fold; it is yellow elastic cartilage
cricoid cartilage the inferior and posterior cartilage of the larynx; it forms a complete cartilaginous ring; its arch projects anteriorly and its lamina is broad and flat posteriorly connected: above to the thyroid cartilage via the inferior horn of the thyroid cartilage, to the conus elasticus, to the arytenoid cartilages which sit atop the lamina; connected below to the first tracheal ring via the cricotracheal ligament
cuneiform cartilage small cartilaginous nodule located in the aryepiglottic fold cuneiform cartilage is yellow elastic cartilage
epiglottis the superior part of the larynx epiglottic cartilage is covered by a mucous membrane
ethmoid delicate bone located between the two orbits highly pneumatized bone that contains the ethmoid air cells; forms the fragile medial wall of the orbit
cribriform plate perforated portion of ethmoid bone on either side of the crista galli perforated for passage of the olfactory nerves
crista galli superior midline projection of the ethmoid bone into the anterior cranial fossa; it arises between the cribriform plates "cock's comb"; anterior anchor point of the falx cerebri
perpendicular plate midline process projecting inferiorly into the nasal cavity forms the superior part of the bony nasal septum
superior nasal concha medial projection of the ethmoid bone from the superolateral wall of the nasal cavity forms the superior nasal meatus below it and the sphenoethmoidal recess above it
middle nasal concha portion of the ethmoid bone that projects inferomedially from the lateral wall of the nasal cavity forms the superior nasal meatus above it and the middle nasal meatus (which overlies the bulla ethmoidalis and hiatus semilunaris) below it
bulla ethmoidalis rounded elevation on the lateral wall of the nasal cavity located under cover of the middle nasal concha; middle ethmoidal air cells drain at its apex
ethmoidal air cells pneumatized spaces (3-18 in number) within the ethmoid bone; located between the orbits three groups may be identified: anterior (drain into the hiatus semilunaris in the middle nasal meatus), middle (drain onto the apex of the bulla ethmoidalis in the middle nasal meatus), posterior (drain into the superior nasal meatus)
ethmoidal foramen, anterior opening in the medial wall of the orbit transmits anterior ethmoidal vessels and nerve
ethmoidal foramen, posterior opening in the medial wall of the orbit transmits posterior ethmoidal vessels and nerve
hiatus semilunaris groove in the ethmoid portion of the lateral nasal wall between the uncinate process below and bulla ethmoidalis above receives the frontonasal duct anterosuperiorly, opening of the maxillary sinus posteroinferiorly, and the openings of the anterior ethmoidal air cells in between
frontal the anterior bone of the skull which underlies the forehead articulates with the parietal bone posteriorly; zygomatic, ethmoid and sphenoid bones inferiorly; maxilla, nasal and lacrimal bones anteriorly; it is formed from two ossifications centers which normally fuse in the midline - if they do not fuse, a midline "metopic suture" is the result
orbital plate flat portion of frontal that forms the roof of the orbit a very thin portion of the frontal bone which is like an egg shell in thickness
foramen cecum opening near the anterior end of the crista galli transmits an emissary vein which may result in transfer of infectious materials from the nasal cavity to the cranial cavity with resulting meningitis
frontal sinus pneumatized space in the frontal bone usually paired; each drains through the frontonasal duct into the uppermost part of the hiatus semilunaris in the middle nasal meatus
superior orbital margin arch of bone above the orbital opening skin over this region is supplied by branches of the frontal nerve (supraorbital and supratrochlear nn.)
superciliary arch the ridge of bone above the orbital margin located deep to the eyebrow, blunt trauma to this region often results in cuts within the eyebrow
glabella midline point between the paired superciliary arches
supraorbital notch notch in the superior orbital margin occasionally present as a foramen; opening for the passage of the for supraorbital neurovascular bundle
hyoid a "U"-shaped bone consisting of several parts: body, 2 greater horns, 2 lesser horns the hyoid bone ossifies completely in middle life; the body articulates with the greater horns via cartilage and with the lesser horns via fibrous joints prior to ossification; an important site for muscle attachments (suprahyoid and infrahyoid muscle groups)
body the middle portion of the "U"-shaped bone the body of the hyoid bone articulates with the greater horns posteriorly
greater horn (cornu) posteriorly directed limbs of the "U"-shaped bone each greater horn articulates with the body and lesser horns anteriorly; origin of middle pharyngeal constrictor m. and hyoglossus m.
lesser horn (cornu) articulates with the greater horn at its junction with the body the inferior end of the stylohyoid ligament attaches to the lesser horn
inferior nasal concha a separate bone on the lateral wall of the nasal cavity it articulates with the maxilla; forms the inferior nasal meatus below it and the middle nasal meatus above it
lacrimal small bone forming part of the medial wall of the orbit articulates: anteriorly with frontal process of maxilla, superiorly with frontal bone, posteriorly with ethmoid, inferiorly with orbital process of maxilla; forms part of the canal for the nasolacrimal duct
mandible the U-shaped bone forming the lower jaw contains the inferior teeth; formed from the mesenchyme of the 1st pharyngeal arch, and its muscles are innervated by the nerve of the 1st arch (mandibular division of cranial nerve V)
body the anterior part of the mandible paired halves are fused in the midline at the symphysis menti
symphysis menti the midline symphysis between the two halves of the mandible the two halves of the mandible fuse during the first postnatal year
mental protuberance the projection on the anterior midline of the mandible the bone of the chin; mental means relating to the mind, a reference to the act of resting the chin on the hand while thinking (see the sculpture by Rodin: "The Thinker")
mental spines (genial tubercles) the spines on the inner surface of the mandible posterior to the mental protuberance attachment site for the genioglossus and geniohyoid mm.
mylohyoid line the ridge running obliquely from posterosuperior to anteroinferior on the medial surface of the body of the mandible attachment site for the mylohyoid muscle; the submandibular gland is located inferior to this line and the sublingual gland is located superior to this line
mental foramen the opening on the anterior surface of the body of the mandible inferior to the premolar teeth transmits the mental neurovascular bundle; covered superficially by the depressor anguli oris and depressor labii inferioris mm.
ramus the angled portion of the mandible that joins the posterior portion of the body it rises nearly vertically from the body; the chondyloid process and the coronoid process extend from the superior end of the ramus; the mandibular foramen is located on the medial surface of the ramus; the medial pterygoid m. attaches to the medial surface and the masseter m. attaches to the lateral surface of the ramus
angle the posteroinferior bend formed by the union of the body and the ramus
mandibular foramen the opening on the medial surface of the ramus it is the opening into the mandibular canal; it transmits the inferior alveolar neurovascular bundle
mandibular canal the canal that runs through the body of the mandible it transmits the inferior alveolar neurovascular bundle from the infratemporal fossa to the mandibular teeth and gingivae
lingula the projection of bone medial to the mandibular foramen it is the attachment site of the inferior end of the sphenomandibular ligament
coronoid process the process that projects anterosuperiorly from the ramus of the mandible it is the attachment site of the temporalis m.
condylar process the rounded process that projects posterosuperiorly from the ramus of the mandible it articulates with the mandibular fossa of the temporal bone
mandibular notch the notch between the coronoid and condylar processes it transmits the masseteric neurovascular bundle from the infratemporal fossa to the deep surface of the masseter m.
mandibular neck the constriction below the articular chondyle on the chondylar process of the mandible part of the lateral pterygoid m. inserts into the pterygoid fossa of the mandibular neck
pterygoid fossa of the neck a shallow depression on the anterior surface of the neck of the mandible part of the lateral pterygoid m. inserts into the pterygoid fossa of the mandibular neck
maxilla bone forming the midface it forms the inferior orbital margin and contains the teeth and maxillary sinus
frontal process the part of the maxilla that projects superiorly medial to the orbit it articulates with the nasal bone, the frontal bone and the lacrimal bone; it forms part of medial orbital wall & margin; it forms the anterior part of the canal for the nasolacrimal duct
orbital process the part of the maxilla that forms the floor of the orbit also known as the orbital surface of the maxilla; it contains the infraorbital groove and canal; it forms the roof of the maxillary sinus
zygomatic process the lateral projection of the maxilla it articulates with the zygomatic bone
infraorbital groove groove in orbital process of the maxilla located in the posterior part of the orbit transmits the infraorbital neurovascular bundle from the infraorbital fissure to the infraorbital canal
infraorbital canal canal in orbital process of the maxilla located in the anterior part of the orbit the direct continuation of the infraorbital groove; transmits the infraorbital neurovascular bundle from the infraorbital groove to the infraorbital foramen
infraorbital foramen opening at the anterior end of the infraorbital canal located inferior to the orbit it transmits the infraorbital neurovascular bundle
alveolar process "U"-shaped process of bone that holds the maxillary teeth contains sockets (alveoli) for the roots of the maxillary teeth
maxillary tuberosity the roughened posterior aspect of the body of the maxilla the posterior superior alveolar nn. Enter the maxilla directly superior to this structure
anterior nasal spine anterior projection of bone in the midline, inferior to the anterior nasal aperture the cartilaginous part of the nasal septum sits atop this structure
maxillary sinus pneumatized hollow center of the body of the maxilla paired; each maxillary sinus drains through the hiatus semilunaris into the middle nasal meatus
palatine process shelf of bone that projects horizontally to meet at the midline in the intermaxillary suture paired; together, they form the roof of the oral cavity (hard palate) and the floor of the nasal cavity
incisive foramen opening in the midline, posterior to the maxillary incisor teeth it transmits the terminal branches of the nasopalatine nn. & sphenopalatine aa.; it marks the point of union during development of the primary and secondary palate
nasal thin bone that forms part of the bridge of the nose articulates with the frontal bone superiorly, the frontal process of the maxilla laterally and the contralateral nasal bone medially
occipital the bone forming the posterior surface of the skull it articulates superolaterally with the parietal bones through the lambdoid suture, anteroinferiorly with the temporal bone and anteriorly with the body of the sphenoid bone
pharyngeal tubercle projection located anterior to the foramen magnum attachment site for the superior pharyngeal constrictor m.
squamous part the flat, thin portion of the occipital bone located posterior to the foramen magnum it articulates with the petrous part of the temporal bone anteroinferiorly and the parietal bones superolaterally at the lambdoid suture
external occipital protuberance a projection on the external surface of the squamous part of the occipital bone in the midline it is the attachment site of the ligamentum nuchae and the trapezius m.; its highest point is called the inion
inferior nuchal line a low ridge that runs transversely on the external surface of the squamous part of the occipital bone inferior to the superior nuchal line it is an attachment site for deep neck muscles
superior nuchal line a low ridge that runs transversely on the external surface of the squamous part of the occipital bone it is the attachment is the for the trapezius and splenius mm.
foramen magnum the opening in the occipital bone posterior to the basal part it transmits the spinal cord, two vertebral aa., and two spinal accessory nerves
basal part the portion of the occipital bone located anterior to the foramen magnum it articulates with the body of the sphenoid bone
lateral part the portion of the occipital bone located lateral to the foramen magnum paired; it is pierced by the hypoglossal canal and the condylar canal
hypoglossal canal an opening in the lateral part of the occipital bone paired; it transmits the hypoglossal nerve
condylar canal an opening in the lateral part of the occipital bone paired; it transmits the condylar emissary vein
occipital condyle a low, wide projection from the inferior surface of the lateral part of the occipital bone paired; it articulates with the atlas
jugular notch a notch located on the anterolateral edge of the lateral part of the occipital bone it forms the posterior margin of the jugular foramen; the temporal bone forms the anterior margin of the jugular foramen
ossicles a chain of three bones in the tympanic cavity (middle ear) connecting the tympanic membrane to the oval window; arranged from lateral to medial: malleus, incus, stapes the ossicles are joined by synovial articulations that may become arthritic in old age, resulting in conductive deafness
incus the middle ossicle of the middle ear articulates with the head of the malleus and the head of the stapes; incus means "anvil"
malleus the lateral ossicle of the middle ear the manubrium is attached by its handle to the inner surface of the tympanic membrane at the umbo; its head articulates with the incus; malleus means "hammer"
stapes the medial ossicle of the middle ear it articulates with the long process of the incus and its base fills the fenestra vestibuli (oval window); stapes means "stirrup"
palatine the bone that forms the posterior part of the hard palate paired; failure of the perpendicular plates to fuse during development leads to a midline defect (cleft palate)
perpendicular plate the vertical portion of the palatine bone located posteriorly on either side of the nasal cavity it articulates anteriorly with the maxilla; posteriorly it forms the medial wall of the pterygopalatine fossa and the lateral wall of the nasal cavity; its posterior edge contributes to 1/2 of the sphenopalatine foramen
sphenopalatine notch a notch at the posterosuperior margin of the perpendicular plate of the palatine bone along with the sphenoid bone it forms the sphenopalatine foramen
sphenopalatine foramen an opening in the lateral wall of the nasal cavity formed by the perpendicular plate of the palatine bone and the body of the sphenoid bone it transmits the nasopalatine nerve and the sphenopalatine vessels
orbital process a small, superior projection from the perpendicular plate of the palatine bone it forms a small part of the floor of the orbit located posteroinferiorly near the apex
horizontal plate the portion of the palatine bone that forms the posterior 1/3 of the hard palate paired; the two horizontal plates meet at the midline
greater palatine foramen an opening in the hard palate located medial to the 3rd maxillary molar tooth it transmits the greater palatine neurovascular bundle; it is an important site for oral anesthesia
lesser palatine foramen an opening in the hard palate located posterior to the greater palatine foramen there may be more than one; it transmits the lesser palatine n. and vessels
parietal a broad, flat bone forming the lateral surface of the skull paired; this bone articulates with the contralateral parietal bone in the midline at the sagittal suture; it articulates anteriorly with frontal bone at coronal suture; it articulates posteriorly with the occipital bone at the lambdoid suture; it articulates inferiorly with the greater wing of the sphenoid bone at the pterion, the squamous part of the temporal bone at the squamous suture and the mastoid part of the temporal bone at the parietomastoid suture
inferior temporal line an arching ridge on the external surface of the parietal bone it is an attachment site for the temporalis muscle
superior temporal line an arching ridge on the external surface of the parietal bone it is an attachment site for the temporalis muscle and the temporal fascia
parietal foramen an opening in the parietal bone located near the sagittal suture it transmits the parietal emissary vein, a valveless vein which connects the scalp to the cranial cavity
granular foveolae small pits located on the inner table of the parietal bone for the arachnoid granulations
thyroid cartilage the large anterior cartilage of the larynx; it has several parts: laminae (2), superior horns (2), inferior horns (2), oblique line, superior thyroid notch, connected above to the hyoid bone via the thyrohyoid membrane; connected below to the cricoid cartilage via the inferior horn of the thyroid cartilage; connected posteriorly: to the arytenoid cartilage via the vocal ligament and thyroarytenoid m., to the epiglottic cartilage via the thyroepiglottic ligament; it tilts anteriorly to increase the length of the vocal ligament and raise the pitch of the voice
lamina a broad flat plate of cartilage forming one side of the thyroid cartilage; two laminae fuse anteriorly in the midline to form the thyroid cartilage the laryngeal prominence is the line of fusion of the two laminae; each lamina is connected superiorly to the hyoid bone by the thyrohyoid membrane
superior horn the rounded, superior projection of the posterior border of the thyroid lamina it is connected superiorly to the greater horn of the hyoid bone by the lateral thyrohyoid ligament
inferior horn the rounded, inferior projection of the posterior border of the thyroid lamina it is connected inferiorly to the cricoid cartilage by the cricothyroid articulation (a synovial joint)
oblique line ridge which descends diagonally from superior to inferior on the lateral surface of the thyroid lamina a line of muscle attachment
laryngeal prominence the line of fusion of the thyroid laminae known to the lay person as the "Adam's apple"; the laryngeal prominence is a secondary sexual characteristic - in postpuberal males the angle of the laryngeal prominence is approximately 90 and in females the angle is approximately 120
superior thyroid notch the notch at the superior end of the laryngeal prominence it is connected to the hyoid bone by the median thyrohyoid ligament
sphenoid an irregularly shaped bone forming the central portion of the skull it has many parts, including a body, greater wing, lesser wing and pterygoid plates
body central part of the sphenoid bone contains the sphenoid sinuses; attachment point for the wings and pterygoid plates
sphenoid sinuses pneumatized spaces within the body of the sphenoid bone usually paired; it drains into the sphenoethmoidal recess of the nasal cavity
jugum the anterior-most portion of the sphenoid bone articulates with the cribriform plate of the ethmoid bone
chiasmatic sulcus the groove for the optic chiasm located between the jugum & the tuberculum sellae
optic canal canal located at the lateral end of the chiasmatic sulcus and medial to the anterior clinoid process paired; it transmits the optic nerve and the ophthalmic artery from the cranial cavity to the apex of the orbit
tuberculum sellae the anterior limit of the sella turcica the middle clinoid processes project from its lateral ends
sella turcica depression on the superior surface of the body of the sphenoid bone "Turkish saddle"; roughly equivalent to the hypophyseal fossa; area between the tuberculum sellae and the posterior clinoid processes
anterior clinoid process projection at the medial end of the lesser wing of the sphenoid bone the internal carotid artery passes medial to this structure
lesser wing of the sphenoid thin rim of bone projecting laterally from the anterior clinoid process bilateral; it forms the posterior margin of anterior cranial fossa; it articulates anteriorly with the orbital plate of the frontal bone
greater wing of the sphenoid broad plate of bone swinging laterally from the body of the sphenoid bone bilateral; it forms the medial part of the floor of the middle cranial fossa, part of temporal fossae laterally, and the posterior part of the lateral wall of orbit; it articulates anteriorly with the zygomatic bone, superiorly with the frontal & parietal bones (at the pterion), posteriorly with the squamous & petrous portions of the temporal bone
superior orbital fissure slit-like opening between the lesser & greater wings of the sphenoid bone it transmits the oculomotor nerve, the trochlear nerve, the abducens nerve, branches of ophthalmic division of the trigeminal nerve, the superior ophthalmic vein and lymphatics from the cranial cavity into the orbit
foramen rotundum opening in the floor of the middle cranial fossa through the greater wing of the sphenoid bone it transmits the maxillary division of the trigeminal nerve
foramen ovale opening in the floor of the middle cranial fossa through the greater wing of the sphenoid bone it transmits the mandibular division of the trigeminal nerve; it is located between the foramen rotundum and the foramen spinosum
foramen spinosum opening in the floor of the middle cranial fossa through the greater wing of the sphenoid bone it transmits the middle meningeal artery and the meningeal br. of the mandibular division of the trigeminal nerve (cranial nerve V)
spine of the sphenoid process of bone that projects inferiorly from undersurface of greater wing of the sphenoid it is the superior attachment for the sphenomandibular ligament
pterygoid process process that projects inferiorly from the junction of the body & greater wing of the sphenoid bone it has several parts: lateral & medial pterygoid plates, hamulus, pterygoid fossa, scaphoid fossa; the pterygoid plates are separated by the large pterygoid fossa throughout most of their length, and by the small scaphoid fossa superiorly
lateral pterygoid plate thin plate of bone that projects posterolaterally from the pterygoid process it is the attachment site of the lateral & medial pterygoid muscles (lateral pterygoid m. on its lateral surface, medial pterygoid m. on its medial surface)
medial pterygoid plate thin plate of bone that projects posteriorly from the pterygoid process it is the attachment of the superior pharyngeal constrictor m. & the pharygobasilar fascia
scaphoid fossa an oval depression at the superior end of the lateral pterygoid plate it is the site of origin of the tensor veli palatini m.
pterygoid hamulus hook-like projection from the inferior end of the medial pterygoid plate it acts as a pulley for the tendon of the tensor veli palatini m.
pterygoid canal canal that occurs at the junction of the greater wing, the pterygoid process and the body of the sphenoid bone it transmits the nerve of the pterygoid canal from the pterygoid region to the pterygopalatine fossa
temporal bone forming the lateral side of the skull temporal refers the passage of time, which is marked by the appearance of gray hair on the side of the head
petrous part the hard part of the temporal bone located in the floor of the cranial cavity it contains the tympanic cavity (middle ear) and the bony labyrinth of the inner ear
internal acoustic meatus the opening on the posteromedial surface of the petrous part of the temporal bone it transmits the facial n., the vestibulocochlear n., and the labyrinthine a.
facial canal a canal which courses through the petrous part of the temporal bone it transmits the facial n. from the internal acoustic meatus to the stylomastoid foramen
carotid canal a canal which courses through the petrous part of the temporal bone it transmits the internal carotid a. and the internal carotid plexus of nerves into the cranial cavity
mastoid process the process located posteroinferior to the external acoustic meatus it projects inferiorly from the junction of the petrous and squamous parts of the temporal bone; it contains the mastoid air cells that open into tympanic cavity through the mastoid antrum
tegmen tympani thin plate of bone forming the roof of the tympanic cavity located on the floor of the middle cranial fossa
jugular fossa a depression on the posterior surface of the petrous part of the temporal bone it forms the anterior margin of the jugular foramen; the occipital bone forms the posterior margin of the jugular foramen
styloid process the spike of bone that projects inferiorly from the petrous part of the temporal bone it is the attachment site for the stylohyoid, styloglossus and stylopharyngeus mm. and the stylomandibular and stylohyoid ligaments
tympanic part the part of the temporal bone consisting of the external acoustic meatus and the tympanic ring the medial 1/3 of the external acoustic meatus is bony and the lateral 2/3 is formed by cartilage
external acoustic meatus the opening in the lateral surface of the temporal bone it extends medially from the surface to the tympanic membrane; it allows sound to reach the tympanic membrane; the medial 1/3 of the external acoustic meatus is bony and the lateral 2/3 is formed by cartilage
tympanic ring the rim of bone surrounding the medial end of the external acoustic meatus it is the attachment site of the tympanic membrane
squamous part the thin flat portion of the temporal bone that constitutes the side of the skull above the ear it articulates with the parietal bone and the greater wing of the sphenoid bone at the squamous suture
zygomatic process the projection of bone that arises anterior to the external acoustic meatus it articulates with the temporal process of the zygomatic bone to form the zygomatic arch
mandibular fossa the depression located medial to the origin of the zygomatic process it articulates with the condylar process of the mandible
articular tubercle an inferior projection located anterior to the mandibular fossa dislocations of the temporomandibular joint result when the mandibular condyle slides anterior to this structure
vomer thin plate of bone forming the posteroinferior part of the nasal septum articulates superiorly with the perpendicular plate of the ethmoid bone and the body of the sphenoid bone; articulates inferiorly with the palatine processes of the maxilla and the horizontal plate of the palatine bone
wormian bone small irregular bone that occurs between sutures of the skull wormian bones are variable in occurrence and are especially common at the junction of the squamous suture and the lambdoid suture
zygomatic the bone that forms the cheek the zygomatic bone is frequently fractured in blows to the side of the orbit; the temporal fascia attaches to the zygomatic arch
temporal process the portion of the zygomatic bone that projects posteriorly it articulates with the zygomatic process of the temporal bone to form the zygomatic arch
frontal process the portion of the zygomatic bone that projects superiorly and medially it forms the inferior part of the lateral orbital margin and the anteroinferior part of the lateral orbital wall; it articulates with the frontal bone anteriorly and the greater wing of the sphenoid bone posteriorly
maxillary process the part of the zygomatic bone that projects medially it forms the lateral part of the inferior orbital margin and the anterolateral part of the orbital floor; it articulates with the maxilla
zygomaticofacial foramen a small opening on the lateral surface of the zygomatic bone it transmits the zygomaticofacial n.

Bones of the Thorax

Bone Structure Description Notes
rib the bone forming the lateral thoracic wall 12 pairs; several types are described: typical or "true" ribs, "false" ribs, "floating" ribs; all three types of ribs have many features in common: head, neck, tubercle, angle, body, costal groove
head posteromedial end of the rib it articulates with demifacets of two adjacent vertebral bodies
neck the constricted region lateral to the head of the rib the neck of the rib is located between the head and the tubercle
tubercle a projection located posteroinferior and lateral to the neck of the rib it articulates with the transverse process of a vertebra
body the shaft of the rib the body is the longest part of a typical rib
angle the marked angulation of the body located just lateral to the tubercle the angle of the rib is its most posterior part
costal groove the groove on the inner surface of the inferior border of the body of the rib it accommodates the intercostal neurovascular bundle; the costal groove provides a protective function for the intercostal neurovascular bundle,
ribs 1-7 "true" ribs - those which attach directly to the sternum true ribs actually attach to the sternum by means of a costal cartilage and a true synovial joint
rib 1 the most cephalic rib it is the broadest, shortest and widest of the ribs; the scalene tubercle marks its superior surface and is an elevation between grooves for the subclavian vein & artery; the scalene tubercle is the attachment site of the scalenus anterior m.
rib 2 the rib attached to the 1st and 2nd thoracic vertebrae it articulates via a costal cartilage with the sternum at the level of the sternal angle; its superior surface is roughened by the attachments of the scalene mm.
rib 8-10 "false" ribs they articulate via costal cartilages with the costal cartilage of rib 7
rib 11-12 "floating" ribs the anterior ends of these ribs do not articulate with the sternum or the costal cartilage of the rib above; their costal cartilages are short and end in the muscle of the posterolateral abdominal wall
sternum the broad flat bone forming the anterior thoracic wall it is formed by three parts: manubrium, body, xiphoid process
manubrium the superior part of the sternum manubrium means "handle", as in the handle of a sword
jugular (suprasternal) notch a notch on the superior border of the manubrium it is located between the clavicular notches which articulate with the sternal ends of the clavicles
clavicular notch a notch on the superolateral border of the manubrium it articulates with the sternal end of the clavicle
sternal angle the junction of the manubrium and body of the sternum it is an anterior projection located at the level of the costal cartilage of rib 2; an important landmark for internal thoracic anatomy
body the middle part of the sternum it articulates with the manubrium superiorly and the xiphoid process inferiorly; laterally it articulates with the costal cartilages of ribs 2-7
xiphoid process the inferior part of the sternum xiphoid means "sword shaped"; it is variable in size, shape & ossification; it articulates with the body of the sternum superiorly

Bones of the Abdomen, Pelvis and Perineum

Bone Structure Description Notes
os coxae one of three bones that form the pelvis paired; the os coxae forms the lateral part of the pelvis; it is formed by three fused bones: ischium, ilium & pubis; also known as the innominate bone
acetabulum a cup-shaped depression in the lateral surface of the os coxae bone acetabulum means vinegar cup; it is the socket for the head of the femur; it is formed by the: ilium (1/5), ischium (2/5) and pubis (2/5); the acetabular fossa lies in the floor of the acetabulum
acetabular notch a notch in the inferior margin of the acetabulum it is spanned by the transverse acetabular ligament; the acetabular br. of the obturator a. enters the hip joint by passing through the acetabular notch
acetabular fossa a roughened depression in the center of the acetabulum the ligament of the head of the femur occupies the acetabular fossa
lunate surface of the acetabulum the smooth articular surface of the acetabulum the lunate surface surrounds the acetabular fossa and the acetabular notch
obturator foramen a large foramen formed by the pubic and ischial rami obturator means to occlude or stop up, a reference to the fact that the obturator membrane closes the obturator foramen almost completely; a site of attachment for the obturator externus m. and the obturator internus m.
pubis an angulated bone the forms the anterior part of the pelvis one of three bones that form the os coxae: ilium, ischium, pubis; its body forms 1/5 of the acetabulum; its symphyseal surface unites with the pubis of the opposite side to form the pubic symphysis; the superior and inferior pubic rami participate in the formation of the obturator foramen
body superolateral portion of the pubis the body of the pubis forms about 1/5 of the acetabulum
pubic crest ridge on the superior border of the superior ramus attachment of rectus abdominis & pyramidalis mm.
pubic tubercle process at the lateral end of pubic crest attachment point of the medial end of the inguinal ligament
superior ramus superior "limb" that passes medially from the body of the pubis articulates with the superior ramus of the opposite side at the pubic symphysis
pecten ridge on superior surface of the superior pubic ramus attachment point of the pectineal ligament
inferior ramus inferior "limb" that passes inferolaterally from the pubic symphysis articulates with the ischial ramus to form the ischiopubic ramus; attachment site for the root of the penis (clitoris) and perineal membrane
obturator groove groove on the inferior surface of the superior pubic ramus marks the area of passage of the obturator vessels and n. in the obturator canal
ischium   the "V"- shaped bone that forms the posteroinferior part of the pelvis one of the three bones that form the os coxae: ilium, ischium, pubis
ischial ramus the limb of the ischium that passes anteriorly and superomedially toward the pubis it articulates with the inferior ramus of the pubis to form the ischiopubic ramus; attachment site for the perineal membrane
body the part of the ischium that participates in the formation of the acetabulum it articulates with the ilium and the pubis at the acetabulum; the body of the ischium forms 2/5 of the acetabulum
ischial tuberosity the roughened projection that protrudes posteroinferiorly from the body of the ischium it is the site of attachment of the sacrotuberous ligament; it is the site of origin of the inferior gemellus m., quadratus femoris m. and the hamstring mm. (semitendinosus, semimembranosus, long head of biceps femoris, ischiocondylar portion of the adductor magnus)
lesser sciatic notch the notch located between the ischial tuberosity and the ischial spine the lesser sciatic notch is converted to the lesser sciatic foramen by the sacrospinous ligament and the sacrotuberous ligament
ischial spine the spine that arises just superior to the lesser sciatic notch it is the site of attachment of the sacrospinous ligament and the site of origin of the superior gemellus m.
ilium fan-shaped bone that forms the lateral prominence of the pelvis one of three bones that form the os coxae: ilium, ischium, pubis
body the portion of the ilium that participates in the formation of the acetabulum the body of the ilium forms 2/5 of the acetabulum
iliac crest arching superior edge the ilium that forms the rim of the "fan" attachment for abdominal wall muscles
iliac fossa broad depression on the medial surface of the ilium iliac fossa is part of the false (greater) pelvis
iliac tubercle roughened area along the outer edge of the iliac crest
anterior superior iliac spine spine at the anterior end of the iliac crest lateral attachment of the inguinal ligament
posterior superior iliac spine spine at the posterior end of the iliac crest position marked by a dimpling of the skin
arcuate line ridge running from anteroinferior to posterosuperior on the inner surface of the ilium inferior boundary of the iliac fossa; marks the plane of transition from abdominal cavity to pelvic cavity
sacrum   a triangular bone that is the posterior skeletal element forming the pelvis it is formed by 5 fused vertebrae; the sacrum and two os coxae bones form the pelvis
base the superior part of the sacrum the base of the sacrum includes the articular surface for the fifth lumbar vertebra and the superior portion of the two ala
promontory a projection of the superior part of the sacrum in an anterior direction the body of the fifth lumbar vertebra sits on the sacral promontory and articulates with it through a symphysis
ala the lateral portion of the sacrum paired; it projects laterally from the body of the sacrum; it represents the fused costal and transverse processes of the first sacral vertebra
anterior sacral foramina an opening in the anterior surface of the sacrum there are four pairs; each transmits the ventral primary ramus of the respective sacral spinal nerve; branches of the lateral sacral aa. enter the sacral canal through these openings
posterior sacral foramina an opening in the posterior surface of the sacrum there are four pairs; each transmits the dorsal primary ramus of the respective sacral spinal nerve
sacral canal the opening in the center of the sacrum it is the continuation of the vertebral canal at sacral vertebral levels
sacral hiatus an opening in the posterior surface of the sacrum in the midline it is a normal feature that results from the failure of fusion of the laminae of the fifth sacral segment (and sometimes the fourth) during development
articular surface the roughened area located on the lateral surface of the sacrum this surface articulates with the ilium in the sacroiliac articulation
body the central portion of the sacrum the body is equivalent to the bodies of the other vertebra
base the superior surface of the sacrum the base of the sacrum articulates with the fifth lumbar vertebra through an intervertebral disk
coccyx   the most inferior portion of the vertebral column the coccyx results from the fusion of the four coccygeal vertebrae; it may be a single bone or the first coccygeal vertebra may be separated from the other three; it articulates with the fifth sacral segment; coccygeal vertebrae are reduced in complexity, having no pedicles, laminae or spines

Bones of the Lower Limb - Listed in Proximal to Distal Order

Bone Structure Description Notes
femur   the bone of the thigh the femur is the longest and strongest bone in the body
  head smooth, rounded proximal end the head of the femur articulates with the acetabulum of the pelvis
fovea capitis femoris a shallow pit in the head of the femur it is the attachment site of the ligamentum capitis femoris; a small artery for supply of the head is found within this ligament
neck the constricted area distal to the head of the femur most of the blood supply to the head of the femur courses along the surface of the neck; fractures of the neck of the femur may result in avascular necrosis of the head
greater trochanter a large process that projects superiorly from the junction of the neck and shaft of the femur the greater trochanter is the insertion site of the gluteus medius m., gluteus minimus m., piriformis m. and obturator internus m.
gluteal tuberosity a roughened area located on the posterior surface of the femur at the superior end of the lateral lip of the linea aspera it is one of the insertion sites of the gluteus maximus m.
lesser trochanter a large process that projects from the posteromedial surface of the femur just distal to neck it is the insertion site of the common tendon of the psoas major and iliacus mm. (iliopsoas m.)
trochanteric fossa a depression on the medial side of the greater trochanter on its posterior surface where the greater trochanter joins the neck it is the insertion site of the obturator internus m., superior gemellus m. and inferior gemellus m.
intertrochanteric line a ridge on the anterior surface of the femur that connects the greater and lesser trochanters it is the line of attachment of the fibrous joint capsule
intertrochanteric crest a heavy ridge on the posterior surface of the femur that connects the greater and lesser trochanters the quadratus femoris m. inserts on the intertrochanteric crest
body the long slender shaft of the femur the linea aspera runs the entire length of the posterior surface of the body
linea aspera a vertical ridge on posterior surface of the femur it is the insertion site of the medial (adductor) group of thigh muscles and the origin of the vastus intermedius m. and the short head of the biceps femoris m.
adductor tubercle a process that projects superior to the medial epicondyle of the femur it is the insertion site of the ischiocondylar part of the adductor magnus m.
medial epicondyle the enlargement of bone on the medial side of the femur just superior to the medial condyle it is the attachment site of the tibial collateral ligament of the knee joint
lateral epicondyle the enlargement of bone on the lateral side of the femur just superior to the lateral condyle it is the attachment site of the fibular collateral ligament and the site of origin of the popliteus m.
medial condyle the rounded inferior end of the femur on the medial side it articulates with the medial condyle of the tibia
lateral condyle the rounded inferior end of the femur on the lateral side it articulates with the lateral condyle of the tibia
intercondylar fossa the deep depression on the posterior surface of the femur between the condyles the anterior and posterior cruciate ligaments are located here
  patellar surface the smooth anterior surface at the inferior end of the femur it articulates with the posterior surface the patella
patella   the bone that forms the knee cap the patella is a sesamoid bone in the tendon of the quadriceps femoris muscle; it provides a protective function by withstanding the grinding forces of the quadriceps femoris tendon against the patellar surface of the femur, especially in full knee flexion
tibia   the bone on the medial side of the leg the tibia is the weight-bearing bone of the leg
  medial condyle the heavy prominence on the medial side of the proximal end of the tibia the medial condyle articulates with the medial condyle of the femur; it is larger than the lateral condyle of the tibia
lateral condyle the heavy prominence on the lateral side of the proximal end of the tibia the lateral condyle articulates with the lateral condyle of the femur and with the head of the fibula
intercondylar eminence the ridge of bone on the proximal end of the tibia that projects between the condyles the intercondylar eminence has a medial and a lateral tubercle; it is the attachment site for the cruciate ligaments, medial meniscus and lateral meniscus
tibial tuberosity the roughened protuberance on the anterior surface of the tibia located just distal to the condyles it is the attachment site of the patellar ligament, which represents the insertion of the quadriceps femoris tendon
body the long, robust shaft of the tibia the medial surface of the body of the tibia is subcutaneous throughout its length; when the shin is painfully bumped, the nerve endings are stimulated in the periosteum covering the body of the tibia
interosseous border the sharp ridge that runs longitudinally along the junction of the lateral surface and the posterior surface of the tibia the interosseous membrane attaches to the interosseous border of the tibia
soleal line a ridge of bone that descends obliquely from lateral to medial on the posterior surface of the tibia it is the site of origin of the soleus m.
medial malleolus the large bony prominence on the medial side of the ankle the medial malleolus of the tibia forms the medial side of the ankle joint; it articulates with the medial surface of the talus
fibula   the slender bone on the lateral side of the leg the fibula is not a weight-bearing bone, it is a muscle attachment bone
  head the enlarged proximal end of the fibula it articulates with the lateral condyle of tibia; the fibular collateral ligament of the knee attaches to the head of the fibula
neck the constricted portion of the fibula located just inferior to the head fractures of the neck of the fibula can injure the common fibular n.
body the long slender shaft of the fibula the interosseous membrane attaches to the entire length of the interosseous border of the fibula
interosseous border the sharp ridge that runs longitudinally along the medial surface of the fibula the interosseous membrane attaches to the interosseous border of the fibula
lateral malleolus the enlarged distal end of the fibula the lateral malleolus of the fibula forms the lateral side of the ankle joint; it articulates with the lateral surface of the talus; forcible lateral displacement of the foot can cause the fibula to fracture superior to the lateral malleolus, a condition called a Pott's fracture
tarsal bones   the bones of the ankle there are seven tarsal bones: talus, calcaneus, navicular, medial cuneiform, intermediate cuneiform, lateral cuneiform, cuboid
talus   the most proximal of the tarsal bones the talus articulates with the medial malleolus of the tibia and the lateral malleolus of the fibula to form the ankle mortise joint
  body the proximal part of the talus its superior (trochlear) part participates in the ankle joint and its inferior part articulates with the calcaneus
  trochlea the superior portion of the body of the talus that lies between the two malleoli it has a smooth articular surface; it participates in the formation of the ankle joint
head the portion of the talus that projects anteriorly it articulates with the navicular bone
neck the constricted part of the talus located proximal to the head
calcaneus   the tarsal bone which forms the heel it is the largest and strongest bone in the foot; a fracture of the calcaneus which separates the tuberosity from the body can be a debilitating injury
  calcaneal tuberosity the posterior roughened area of the calcaneus which contacts the ground during weight-bearing it is the insertion site of the calcaneal (Achilles') tendon
sustentaculum tali the shelf-like medial projection of bone located inferior to the medial malleolus it is a shelf of bone that articulates with and supports the talus; it is grooved inferiorly by the tendon of the flexor hallucis longus m.
navicular   the tarsal bone located distal to the talus and proximal to the three cuneiform bones it articulates with the head of the talus and all three cuneiform bones; it is the attachment site for an important ligament (plantar calcaneonavicular or "spring" ligament) that supports the medial longitudinal arch of the foot
cuneiform, medial   the most medial bone in the distal row of tarsal bones the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally
cuneiform, middle the intermediate bone of the three cuneiform bones the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally
cuneiform, lateral the bone that is located between the middle cuneiform and the cuboid bone the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally
cuboid   the most lateral bone in the distal row of tarsal bones the cuboid bone articulates with the calcaneus proximally and the fourth and fifth metatarsal bones distally
metatarsals   the bones located between the tarsal bones and the phalanges there are five metatarsal bones in the foot
base the proximal end of the metatarsal it articulates with the distal row of tarsal bones
body the slender shaft of the metatarsal it is also known as the diaphysis
head the rounded distal end of the metatarsal it articulates with the proximal phalanx of the corresponding digit
phalanx (phalanges)   the distal two or three bones in the digits of the foot there are a total of 14 phalanges in the foot; the great toe has two phalanges (proximal and distal) and each of the other four toes has three phalanges (proximal, middle and distal); phalanx means "line of soldiers"
base the proximal end of the phalanx the base of the proximal phalanx articulates with the head of the corresponding metatarsal bone; the base of the middle or distal phalanx articulates with the head of the next most proximal phalanx
body the slender shaft of the phalanx also known as the diaphysis; the body of the distal phalanx is very short
head the distal end of the phalanx the proximal, middle and distal phalanges each have a head; the head of a proximal or middle phalanx articulates with the base of the next most distal phalanx


Some of the material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest and Jaye Schlesinger
Published by ILOC, Inc., New York. Copyright 1995.

The content of these tables has been edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2009, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.
Unauthorized use is prohibited.



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