Breast, Anterior Axioappendicular Muscles of the Upper Limb

Gross Anatomy


Superficial Features of the Thoracic Wall; Breasts; Anterior Axioappendicular Muscles


Anatomy Tables for Today's Topic


Bones of the Pectoral Region
Muscles of the Pectoral Region and Anterior Thoracic Wall
Joints of the Anterior Thorax
Nerves of the Pectoral Region
Arteries of the Pectoral Region
Fasciae of the Pectoral Region
Topographic Anatomy of the Pectoral Region




Bones of the Pectoral Region

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 which attaches it to 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
glenoid fossa 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
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
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)
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 humerus it articulates with the glenoid cavity of the scapula to form the shoulder joint
anatomical neck the constricted region located adjacent 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 vessels
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. which are three members of the rotator cuff group
lesser tubercle the projection located on the anterior surface of the proximal end of the humerus it is the insertion site of the subscapularis m., a member of the rotator cuff group
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.
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 tendon of the long head of the biceps in place; it is the attachment site for the tendon of the pectoralis major (lateral lip), teres major (medial lip), and latissimus dorsi (floor)
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.
rib the skeletal element of the 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 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

Muscles of the Pectoral Region and Thoracic Wall

Muscle Origin Insertion Action Innervation Artery Notes
pectoralis major medial 1/2 of the clavicle, manubrium & body of sternum, costal cartilages of ribs 2-6, sometimes from the rectus sheath of the upper abdominal wall crest of the greater tubercle of the humerus flexes and adducts the arm, medially rotates the arm medial and lateral pectoral nerves (C5-T1) pectoral branch of the thoracoacromial trunk; also, the deltoid branch of the thoracoacromial trunk supplies the insertion end of this muscle the deep fascia on the anterior surface of the pectoralis major m. should be separated from the mammary gland by the retromammary bursa - if fused to the gland, this is an important clinical sign indicating breast disease
pectoralis minor ribs 3-5 coracoid process of the scapula draws the scapula forward, medialward, and downward medial pectoral nerve (C8, T1) pectoral branch of the thoracoacromial trunk branches of medial pectoral nerve usually pierce pectoralis minor to reach the pectoralis major muscle
subclavius first rib and its cartilage inferior surface of the clavicle draws the clavicle (and hence the shoulder) down and forward nerve to subclavius (C5) clavicular br. of the thoracoacromial trunk it serves an important protective function - it cushions the subclavian vessels from bone fragments in clavicular fractures
serratus anterior ribs 1-8 or 9 medial border of the scapula on its costal (deep) surface it draws the scapula forward; the inferior fibers rotate the scapula superiorly long thoracic nerve (from ventral primary rami C5-C7) lateral thoracic a. a lesion of long thoracic nerve will cause winging of the scapula (i.e., the medial border of the scapula falls away from the posterior chest wall and looks like an angel's wing)

Joints of the Anterior Thorax

Joint or ligament Description Notes
sternoclavicular joint the joint what connects the clavicle with the sternum a synovial joint; its joint capsule is subdivided by a fibrous articular disc; it is strengthened by the sternoclavicular, interclavicular and costoclavicular ligaments; the sternoclavicular joint has the range of movement, but not the form, of a ball and socket joint
sternoclavicular ligament a ligament that reinforces the capsule of the sternoclavicular joint the sternoclavicular ligament has two parts: anterior and posterior; it is a very strong ligament; the combined effect of this ligament, the costoclavicular ligament and the interclavicular ligament is to produce a very strong sternoclavicular joint that seldom dislocates
coracoclavicular joint the joint between the coracoid process of the scapula and the inferior surface of the lateral portion of the clavicle a syndesmosis; this joint provides stability to the acromioclavicular joint
coracoclavicular ligament the ligament that connects the upper surface of the coracoid process to the under surface of the clavicle it has two parts: conoid ligament (posteromedial part) and trapezoid ligament; tearing of the coracoclavicular ligament permits the acromion to move inferior to the distal end of the clavicle (shoulder separation), a condition which could result from a fall on the point of the shoulder
coracoacromial ligament the ligament that connects the coracoid process to the acromion of the scapula it passes superior to both the head of the humerus and the supraspinatus tendon; it provides support for the head of the humerus that prevents superior dislocation
sternocostal joints the articulations that connect the costal cartilages with the sternum a synchondrosis (rib 1) or synovial joints (ribs 2-10); sternocostal synovial joints involving ribs 2-7 contain thin joint capsules; interchondral joints involving ribs 8-10 have simple gliding synovial articulations; radiate sternocostal ligaments reinforce the sternocostal articulations
xiphisternal joint the articulation that connects the xiphoid process with the body of the sternum a synchondrosis; the cartilage within this joint usually becomes ossified in old age; the xiphisternal joint marks the inferior extent of the thoracic cavity

Nerves of the Pectoral Region

Nerve Source Branches Motor Sensory Notes
intercostal n. ventral primary rami of spinal nerves T1-T11 lateral & anterior cutaneous brs. intercostal muscles; abdominal wall muscles (via T7-T11); muscles of the forearm and hand (via T1) skin of the chest and abdomen anterolaterally; skin of the medial side of the upper limb (via T1-T2) intercostal n.travels below the posterior intercostal a. in the costal groove
lateral pectoral n. lateral cord of the brachial plexus no named branches pectoralis major m. no cutaneous branches lateral pectoral n. communicates with the medial pectoral n. anterior to the axillary a.; it pierces the clavipectoral fascia
medial pectoral n. medial cord of the brachial plexus no named branches pectoralis minor m., pectoralis major m. no cutaneous branches medial pectoral n. communicates with the lateral pectoral n. anterior to the axillary a.; it pierces the pectoralis minor m.
subclavius m., n. to superior trunk of the brachial plexus no named branches subclavius m. no cutaneous branches nerve to subclavius m. is one of two nerves to arise from the superior trunk of the brachial plexus; suprascapular n. is the other one
supraclavicular, intermediate cervical plexus (C3&C4) no named branches postganglionic sympathetic skin of the root of the neck and upper chest, near the mid-clavicle pain from respiratory diaphragm is referred to the shoulder
supraclavicular, lateral cervical plexus (C3&C4) no named branches postganglionic sympathetic skin of the root of the neck and upper shoulder pain from respiratory diaphragm is referred to the shoulder
supraclavicular, medial cervical plexus (C3&C4) no named branches postganglionic sympathetic skin of the root of the neck and upper chest, anteriorly pain from respiratory diaphragm is referred to the shoulder
intercostal n. ventral primary rami of spinal nerves T1-T11 lateral & anterior cutaneous brs. intercostal muscles; abdominal wall muscles (via T7-T11); postganglionic sympathetic skin of the chest and abdomen anterolaterally; skin of the medial side of the upper limb (via T1-T2) intercostal n. travels below the posterior intercostal a. in the costal groove

Arteries of the Pectoral Region

Artery Source Branches Supply to Notes
thoracoacromial axillary a., 2nd part pectoral br., clavicular br., acromial br., deltoid br. pectoralis major m., pectoralis minor m., subclavius m., deltoid m., shoulder joint thoracoacromial trunk pierces the costocoracoid membrane
pectoral thoracoacromial trunk unnamed muscular branches pectoralis major m., pectoralis minor m. pectoral br. of thoracoacromial a. accompanies the lateral pectoral n.
clavicular thoracoacromial trunk unnamed muscular branches subclavius m. this vessel also supplies the sternoclavicular joint
acromial thoracoacromial trunk unnamed muscular branches deltoid m. participates in formation of a network of vessels on the surface of the acromion
deltoid thoracoacromial trunk unnamed muscular branches deltoid m., pectoralis major m. deltoid br. of thoracoacromial a. accompanies the cephalic v. in the deltopectoral groove

Topographic Anatomy of the Pectoral Region

Structure/Space Description/Boundaries Significance
midaxillary line an imaginary vertical line passing through the middle of the axilla used as a surface landmark for descriptive purposes
midclavicular line an imaginary vertical line passing through the midshaft of the clavicle used as a surface landmark for descriptive purposes
nipple located superficial to the 4th intercostal space in the male and prepuberal female location of the left nipple may be used to help locate the apex of heart, which is approximately 8 cm from the midline in the left 5th intercostal space; a surface landmark used to place the stethoscope for auscultation of the mitral valve
sternal angle a protrusion on the anterior thoracic wall at the junction of the manubrium and body of the sternum (manubriosternal symphysis) sternal angle is the location of the attachment of the costal cartilage of the 2nd rib to the sternum; an imaginary horizontal plane through the sternal angle passes through the T4/T5 intervertebral disc and marks the inferior boundary of the superior mediastinum
suprasternal notch the notch located at the superior border of the manubrium of the sternum, between the sternal ends of the clavicles also known as: jugular notch

Fasciae of the Pectoral Region

Structure Location/Description Notes
fascia, axillary deep fascia which forms the floor of the axilla inferiorly axillary fascia is attached to the suspensory ligament of the axilla; it is continuous with the pectoral fascia
fascia, clavipectoral a layer of deep fascia attaching to the clavicle superiorly and the axillary fascia inferiorly clavipectoral fascia has several named subdivisions: it surrounds the subclavius m. and is thickened inferior to the muscle where it is called the costocoracoid ligament; clavipectoral fascia extends inferiorly from the costocoracoid membrane to the pectoralis minor m., a part which is called the costocoracoid membrane (pierced by the cephalic v., lateral pectoral n., thoracoacromial a.); it encloses the pectoralis minor m. then continues inferolaterally to attach to the axillary fascia; the part of the clavipectoral fascia that spans from the pectoralis minor m. to the axillary fascia is called the suspensory ligament of the axilla
fascia, pectoral deep fascia which covers the pectoralis major m. pectoral fascia becomes continuous with axillary fascia at the lateral border of the pectoralis major m.


Other Tables of Interest:


Back Region


Upper Limb

All Anatomy Tables

Tables Organized by System Tables Organized by Region

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.

Content of tables edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2005, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.

Unauthorized use is prohibited.