UAMS Gross Anatomy

Gross Anatomy


Hip and Buttocks: The Gluteal Region


Anatomy Tables for Today's Topic

Bones of the Gluteal Region
Muscles of the Gluteal Region
Nerves of the Gluteal Region
Arteries of the Gluteal Region
Lymphatics
Topographic Anatomy
Joints

Bones of the Gluteal Region

Bone Structure Description Notes
os coxae (pelvic or innominate bone)three fused bones: ischium, ilium & pubis
acetabulumsocket for head of femur
acetabular notchnotch in the inferior margin of the acetabulum
lunate surface of acetabulumsmooth articular surface within the acetabulum
obturator foramenlarge foramen surrounded by the superior and inferior pubic rami, the ischial ramus and the acetabulum
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)
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
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
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.

Muscles of the Gluteal Region

Muscle Origin Insertion Action Innervation Artery Notes
gemellus, inferior ischial tuberosity obturator internus tendon laterally rotates the femur nerve to the quadratus femoris m. inferior gluteal a. gemellus is a Latin word that means "little twin"
gemellus, superior ischial spine obturator internus tendon laterally rotates the femur nerve to the obturator internus m. inferior gluteal a. gemellus is a Latin word that means "little twin"
gluteus maximus posterior gluteal line, posterior surface of sacrum and coccyx, sacrotuberous ligament upper fibers: iliotibial tract; lowermost fibers: gluteal tuberosity of the femur extends the thigh; laterally rotates the femur inferior gluteal nerve superior and inferior gluteal aa. gluteus maximus is a site of intramuscular injection
gluteus medius external surface of the ilium between the posterior and anterior gluteal lines greater trochanter of the femur abducts the femur; medially rotates the thigh superior gluteal nerve superior gluteal a. the angle at which the gluteus medius tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation
gluteus minimus external surface of the ilium between the anterior and inferior gluteal lines greater trochanter of the femur abducts the femur; medially rotates the thigh superior gluteal nerve superior gluteal a. the angle at which the gluteus minimus tendon approaches the greater trochanter of the femur is anterior to the axis of rotation of the thigh, resulting in medial rotation
obturator externus the external surface of the obturator membrane and the superior and inferior pubic rami trochanteric fossa of the femur laterally rotates the thigh obturator nerve obturator a. the tendon of the obturator externus m. passes inferior to the neck of the femur to reach its insertion site
obturator internus the internal surface of the obturator membrane and margin of the obturator foramen greater trochanter on its medial surface above the trochanteric fossa laterally rotates and abducts the thigh nerve to the obturator internus m. obturator a. the obturator internus m. leaves the pelvis by passing through the lesser sciatic foramen; the superior and inferior gemellus mm. insert on the obturator internus tendon
piriformis anterior surface of sacrum upper border of greater trochanter of femur laterally rotates and abducts thigh ventral rami of S1-S2   piriformis leaves the pelvis by passing through the greater sciatic foramen
quadratus femoris lateral border of the ischial tuberosity quadrate line of the femur below the intertrochanteric crest laterally rotates the thigh nerve to the quadratus femoris m. inferior gluteal a. the nerve to the quadratus femoris m. also innervates the inferior gemellus m.
tensor fasciae latae anterior part of the iliac crest, anterior superior iliac spine iliotibial tract flexes, abducts, and medially rotates the thigh superior gluteal nerve superior gluteal a. tensor fascia latae redirects the rotational forces of the gluteus maximus m.

Nerves of the Gluteal Region

Nerve Source Branches Motor Sensory Notes
gluteal, inferior sacral plexus (ventral primary rami of spinal nerves L5, S1-S2) no named branches gluteus maximus m. none inferior gluteal n. passes through the greater sciatic foramen inferior to the piriformis m.
gluteal, superior sacral plexus (ventral primary rami of spinal nerves L4-L5, S1) superior & inferior brs. gluteus medius m., gluteus minimus m., tensor fasciae latae m. none superior gluteal n. passes through the greater sciatic foramen superior to the piriformis m.
sciatic n. sacral plexus (ventral primary rami of spinal nerves L4-L5 and S1-S3) tibial n., common fibular (peroneal) n. semitendinosus m., semimembranosus m., biceps femoris m., ischioconylar part of the adductor magnus m.; its branches supply all muscles of the leg and foot its branches supply the skin of the leg and foot (excluding the medial side of leg & foot) sciatic n. is composed of tibial and common fibular divisions; branches to muscles come from one of the two divisions, so that the sciatic n. is considered to have no direct muscular brs., only 2 terminal brs.
to obturator internus m. sacral plexus (ventral primary rami of spinal nerves L5-S2 ) n. to the superior gemellus m. obturator internus m., superior gemellus m. none nerve to obturator internus m. crosses the ischial spine and enters the ischioanal fossa by passing through the lesser sciatic foramen
to quadratus femoris m. sacral plexus (ventral primary rami of spinal nerves L4-L5, S1) n. to the inferior gemellus m. quadratus femoris m., inferior gemellus m. none nerve to the quadratus femoris m. passes anterior to the obturator internus tendon

Arteries of the Gluteal Region

Artery Source Branches Supply to Notes
femoral external iliac a. superficial epigastric a., superficial circumflex iliac a., superficial external pudendal a., deep external pudendal a., deep femoral a., descending genicular a., popliteal a. thigh, leg and foot femoral a. is continuous with the popliteal a., the name change occurs at the adductor hiatus
femoral, deep femoral a. medial circumflex femoral a., lateral circumflex femoral a., perforating aa. (3 or 4) hip joint, proximal thigh, posterior thigh deep femoral a. is the primary blood supply to muscles of the posterior compartment of the thigh
gluteal, inferior internal iliac a., anterior division unnamed muscular branches gluteus maximus m., hip joint inferior gluteal a. participates in the formation of the cruciate anastomoses of the hip
gluteal, superior internal iliac, posterior division superficial br., deep br. gluteus maximus m., gluteus medius m., gluteus minimus m., hip joint superior gluteal a. participates in the formation of the cruciate anastomoses of the hip
obturator internal iliac a., anterior division pubic br., acetabular br., anterior br., posterior br. medial thigh and hip anterior and posterior brs. pass on the anterior and posterior sides of the adductor brevis m.; aberrant obturator a. arises from the inferior epigastric a. in 30% of cases

Topographic Anatomy

Structure/Space Description/Boundaries Significance
lateral compartment , thigh a connective tissue compartment that contains the muscles of the gluteal region; it is located posterolateral to the hip joint lateral compartment of the thigh contains: tensor fasciae latae m., gluteus maximus m., gluteus medius m., gluteus minimis m., piriformis m., superior and inferior gemellus mm., quadratus femoris m.; obturator internus tendon; also known as: gluteal compartment of the thigh

Lymphatics

Structure Location Afferents from Efferents to Regions drained Notes
common iliac nodes along the common iliac vessels; over the sacral promontory external iliac nodes, internal iliac nodes lumbar (lateral aortic) chain of nodes lower limb; pelvic organs, perineum, lower part of the anterior abdominal wall common iliac nodes are approximately 6 in number
deep inguinal nodes along the medial side of the femoral v. deep to the fascia lata and inguinal ligament superficial inguinal nodes, popliteal nodes external iliac nodes lower limb, external genitalia, lower part of the anterior abdominal wall the deep inguinal node in the femoral canal is called the node (or gland) of Cloquet
superficial inguinal nodes in the superficial fascia parallel to the inguinal ligament and along the terminal part of the greater saphenous v. lymphatic vessels from the superficial lower limb, superficial abdominal wall, perineum external iliac nodes; deep inguinal nodes lower abdominal wall; external genitalia; superficial parts of the lower limb superficial inguinal nodes are 12-20 in number; they become inflamed during infections of the lower limb; they may become inflamed during infections of the external genitalia
common iliac nodesalong common iliac vesselsexternal & internal iliac nodeslumbar/lateral aortic nodeslower limb, pelvis & perineum, lower abdominal wall

Joints

Joint or ligament Description Notes
acetabular labrum a fibrocartilage rim around the acetabulum the acetabular labrum deepens the acetabulum; it cups around the head of the femur and holds it firmly in the acetabulum
hip joint the articulation between the os coxae and the head of the femur a synovial ball and socket joint; it is reinforced by capsular ligaments (iliofemoral, pubofemoral, ischiofemoral, zona orbicularis); the fibers of the articular capsule become taut on hip extension and lax on hip flexion; dislocation injuries of the hip are most common when the hip is flexed (sitting in a car seat during an impact that causes the knees to strike the dash board, for example)
iliofemoral ligament the ligament reinforcing the anterior surface of the articular capsule of the hip joint the iliofemoral ligament is shaped like an inverted "Y"; it connects the anterior inferior iliac spine to the anterior surface of the intertrochanteric line of the femur; also known as: ligament of Bigelow
ischiofemoral ligament the ligament reinforcing the posterior surface of the articular capsule of the hip joint the ischiofemoral ligament connects the body of the ischium to the posterior portion of the femoral neck
ligament of the head of the femur an intracapsular ligament that attaches to the fovea of the head of the femur and to the acetabular fossa the ligament of the head of the femur contains a small artery (the a. of the ligament of the head of the femur) which supplies the femoral head; in fractures of the neck of the femur the retinacular aa. that course along the neck may be damaged, so that the artery to the head may be the only blood supply to the head and proximal neck
pubofemoral ligament the ligament reinforcing the medial surface of the articular capsule of the hip joint the pubofemoral ligament connects the pubic portion of the rim of the bony acetabulum to the medial surface of the femoral neck
transverse acetabular ligament the ligament that spans the acetabular notch near the rim of the acetabulum the acetabular branch of the obturator artery enters the hip joint by passing beneath the transverse acetabular ligament; the artery of the ligament of the head of the femur is a branch of the acetabular a.

Other Tables of Interest:


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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 these tables has been edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2006, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.

Unauthorized use is prohibited.