[Anatomy] Gluteal Region & Thigh

Front 1

gluteal region (area)

Back 1

posterior to pelvis from level of iliac crests (L4) to the inferior border of gluteus maximus; Intergluteal cleft is midline groove

Front 2

gluteal fold

Back 2

marks inferior border of the gluteus maximus; disappears when hip joint is flexed; marks the boundary between gluteal region and posterior thigh

Front 3

intramuscular injections

Back 3

gluteal region is a common site; In order to avoid the sciatic nerve, the superolateral quadrant is considered a "safe zone" for injection

Front 4

superficial gluteal muscles

Back 4

gluteus maximus, gluteaus medius, gluteus minimus, tensor fascia lata; innervation by inferior or superior gluteal nerves

Front 5

gluteus maximus

Back 5

• Origin: ilium, sacrum, coccyx, sacrotuberous ligament
• Insertion: iliotibial tract and gluteal tuberosity of the femur
• Innervation: inferior gluteal n.
• Action: extend hip joint (e.g., rising from sitting position, climbing stairs)
• Associated Bursae: Trochanteric; Ischial

Front 6

gluteus medius

Back 6

• Origin: ilium (deep to gluteus maximus)
• Insertion: greater trochanter of femur
• Innervation: superior gluteal n.
• Action: abduct hip joint; keep pelvis level when contralateral leg is raised

Front 7

gluteus minimus

Back 7

▪ Origin: ilium (deep to gluteus medius)
▪ Insertion: greater trochanter
▪ Innervation: superior gluteal n.
▪ Action: abduct hip joint; keep pelvis level when contralateral leg is raised

Front 8

tensor fascia lata

Back 8

▪ Origin: ASIS
▪ Insertion: iliotibial tract
▪ Innervation: superior gluteal n.
▪ Action: tense the fascia lata, thus improving efficiency of other thigh muscles and assisting venous return

Front 9

lesion of superior gluteal nerve

Back 9

o If the superior gluteal n. is injured, when a person is asked to stand on one limb, the pelvis tilts towards the unsupported side (this is called a positive Trendelenburg test)
o So, injury to the left superior gluteal n. will cause the pelvis to tilt on the right side.

Front 10

deep gluteal muscles

Back 10

laterally rotate and stabilize hip joint; innervation by branches of sacral plexus; priformis, obturator internus, superior and inferior gemelli, quadratus femoris

Front 11

piriformis

Back 11

▪ part of deep gluteal muscles
▪ inn: branches of sacral plexus, action: laterally rotate and stabilize hip
▪ Superior gluteal vessels/nerve emerge superior to it
▪ Inferior gluteal vessels/nerve emerge inferior to it
▪ Origin: anterior surface of the sacrum
▪ Insertion: greater trochanter

Front 12

obturator internus

Back 12

▪ deep gluteal muscle; laterally rotate and stabilize hip joint; innervation: branches of sacral plexus
- Origin: internal aspect of obturator membrane and border of obturator foramen
▪ Insertion: trochanteric fossa

Front 13

superior and inferior gemelli

Back 13

▪ part of deep gluteal muscles
▪ laterally rotate and stabilize hip joint
▪ inn: branches of sacral plexus
▪ Origin: ischial spine (superior gemellus); ischial tuberosity (inferior gemellus)
▪ Insertion: trochanteric fossa

Front 14

quadratus femoris

Back 14

▪ deep gluteal muscle
▪ laterally rotate and stabilize hip joint
▪ inn: branches of sacral plexus
▪ Origin: ischial tuberosity
▪ Insertion: intertrochanteric crest

Front 15

gluteal vessels

Back 15

• Gluteal arteries arise from the internal iliac a.
• Superior gluteal a.
o Exits greater sciatic foramen superior to piriformis
• Inferior gluteal a.
o Exits greater sciatic foramen inferior to piriformis
• Superior and inferior gluteal veins accompany the arteries and are tributaries of the internal iliac vein

Front 16

sciatic nerve

Back 16

• (L4-S3)
• Exits greater sciatic foramen inferior to piriformis
• Courses deep to gluteus maximus (but does NOT innervate gluteal muscles)
• Sciatic nerve really consists of two nerves: tibial n. and common fibular n.

Front 17

tibial and common fibular nerve

Back 17

usually separate in the distal thigh (e.g., just proximal to the popliteal fossa); however, this can vary (e.g., in ~12% of people, the two nerves separate as they leave the pelvis, with the common fibular n. passing through piriformis)

Front 18

pifiromis syndrome

Back 18

• Excessive use of the gluteal muscles in some athletes (e.g., ice skaters, cyclists, rock climbers) can lead to hypertrophy or spasm of the piriformis muscle, which can compress the sciatic nerve

Front 19

compression of common fibular nerve

Back 19

In individuals with a proximal split of the sciatic nerve (~12%), the common fibular n. can become compressed as it passes through piriformis.

Front 20

posterior compartment of thigh

Back 20

hamstrings (inn: tibial nerve, extend hip joint and flex knee joint), short head of biceps femoris (inn: common fibular n, flex knee joint)

Front 21

hamstrings

Back 21

posterior compartment of thigh
▪ Origin: ischial tuberosity
▪ Innervation: tibial n. (of sciatic n.)
▪ Action: extend hip joint and flex knee joint
▪ Semitendinosus (medial)
o Insertion: medial aspect of proximal tibia
▪ Semimembranosus (medial, deep to semitendinosus)
o Insertion: medial tibial condyle
▪ Long head of Biceps femoris (lateral)
o Insertion: proximal fibula

Front 22

short head of biceps femoris

Back 22

posterior compartment of thigh
▪ Origin: linea aspera
▪ Insertion: proximal fibula (via shared tendon with long head)
▪ Innervation: common fibular n. (of sciatic n.)
▪ Action: flex knee joint

Front 23

anterior compartment of thigh

Back 23

action: flex hip joint and extend knee joint; innervation: femoral nerve; iliopsoas, sartorius, quadriceps femoris, pectineus

Front 24

femoral nerve

Back 24

o (L2-L4)
o Passes deep to the inguinal ligament
o Innervates muscles in the anterior compartment of the thigh and skin on anteromedial thigh
o Terminal branch, the saphenous nerve, innervates skin on anteromedial aspect of knee, leg, and foot

Front 25

iliopsoas

Back 25

▪ anterior compartment of thigh
▪ Origin: iliac fossa (iliacus); lumbar vertebrae (psoas major)
▪ Insertion: lesser trochanter of femur
▪ Action: flex hip joint (if LE is free); flex and stabilize the trunk (if LE is fixed)

Front 26

psoas abscess

Back 26

Infections/diseases (e.g., tuberculosis) of posterior abdominal structures (e.g., vertebrae) can spread to the sheath covering psoas major

Front 27

iliopsoas test

Back 27

Iliopsoas is closely related to many abdominal organs. In cases of suspected intra-abdominal disease/inflammation, the patient is asked to flex the hip joint against resistance on the affected side

Front 28

sartorius

Back 28

▪ anterior compartment of thigh
▪ Origin: ASIS
▪ Insertion: medial aspect of proximal tibia
▪ Action: flex, abduct, laterally rotate hip joint; flex knee joint (sit cross legged)

Front 29

muscles of quadriceps femoris

Back 29

rectus femoris, vastus lateralis, vastus medialis, vastus intermedius

Front 30

quadriceps femoris

Back 30

in anterior compartment of thigh; flex hip joint and extend knee joint, innervated by femoral nerve
o rectus femoris, vastus lateralis, vastus medialis, vastus intermedius

Front 31

rectus femoris

Back 31

• part of quadriceps femoris of anterior compartment
▪ inn: femoral nerve
▪ Origin: anterior inferior iliac spine (AIIS)
• Action: flex hip joint and extend knee joint

Front 32

vastus lateralis

Back 32

• part of quadriceps femoris of anterior compartment
▪ inn: femoral nerve
▪ Origin: greater trochanter and linea aspera
• Action: extend knee joint

Front 33

vastus medialis

Back 33

• part of quadriceps femoris of anteiror compartment
▪ inn: femoral nerve
▪ Origin: linea aspera
• Action: extend knee joint

Front 34

vastus intermedius

Back 34

• part of quadriceps femoris of anterior compartment of thigh
▪ inn: femoral nerve
▪ Origin: femoral shaft (deep to rectus femoris)
• Action: extend knee joint

Front 35

quadriceps tendon

Back 35

4 parts of quadricep unite distally to form the quadriceps tendon; continues as patellar ligament and inserts on the tibial tuberosity

Front 36

patella

Back 36

▪ (large sesamoid bone) is embedded in quadriceps tendon
▪ Protects the joint capsule and quadriceps tendon, particularly during activities like kneeling
▪ Increases leverage of the quadriceps (increasing the power of knee extension)

Front 37

patellar tendon reflex

Back 37

tests the L4 spinal nerve. With knees flexed and relaxed, the patellar ligament is tapped to elicit a "knee jerk" reaction (patellar reflex). Tapping the patellar ligament stimulates nerve fibers in the quadriceps, causing the muscle to contract and extend the knee.

Front 38

prepatellar bursa

Back 38

between skin and patella; can develop bursitis

Front 39

suprapatellar bursa

Back 39

deep to quadriceps tendon; can develop bursitis

Front 40

trochanter bursa

Back 40

between gluteus maximus and greater trochanter

Front 41

ischial bursa

Back 41

between gluteus maximus and ischial tuberosity

Front 42

pectineus

Back 42

▪ Origin: pubis
▪ Insertion: proximal femur
▪ Action: adduct hip joint; weakly flex hip joint
▪ Innervation: typically femoral n. (similar to the rest of the compartment), but may receive branch of obturator n.)

Front 43

medial compartment of thigh

Back 43

• Origin: pubis
• Action: adduct hip joint
• Innervation: obturator nerve (L2-L4)
• adductor longus, brevis, magnus; gracilis, obturator externus

Front 44

obturator nerve

Back 44

o (L2-L4)
o Courses along lateral wall of pelvis and exits via obturator canal
o Innervates muscles of medial compartment of thigh; skin on medial thigh

Front 45

adductor longus

Back 45

Insertion: linea aspera; addcut hip joint; in medial compartment of thigh

Front 46

adductor brevis

Back 46

medial compartment of thigh; deep to pectineus and adductor longus; insertion: linea aspera

Front 47

adductor magnus

Back 47

o Adductor part
• Insertion: linea aspera
▪ action: adduct hip, inn: obturator

o Hamstring part
• Origin: ischial tuberosity
• Insertion: adductor tubercle of femur
• Action: extend hip joint
• Innervation: tibial n. (of sciatic n.)
• Distally, its tendon creates the adductor hiatus

Front 48

gracilis

Back 48

▪ medial compartmentn of thigh
▪ inn: obturator nerve
▪ forms pes anserinus with tendons of sartorius and semitendinosus
▪ Insertion: medial aspect of proximal tibia
▪ Actions: weakly adduct hip joint, flex/medially rotate knee joint

Front 49

pes anserinus

Back 49

The tendons of gracilis, sartorius, and semitendinosus fuse distally to insert on the proximal tibia, forming the pes anserinus, or "goose's foot." Irritation of the bursa underlying the pes anserinus (pes anserinus bursitis) can cause pain on the medial aspect of the knee.

Front 50

obturator externus

Back 50

▪ medial compartment of thigh; Origin: external aspect of obturator membrane, border of obturator foramen
▪ Insertion: trochanteric fossa of femur
▪ Action: laterally rotate and stabilize the hip joint

Front 51

arteries of thigh

Back 51

femoral artery, deep artery of thigh, lateral and medial circumflex femoral arteries, obturator artery

Front 52

veins of thigh

Back 52

great saphenous vein, deep veins (accompany arteries and share the same names; femoral vein), perforating veins

Front 53

femoral vein

Back 53

▪ Receives blood from popliteal vein, deep vein of the thigh, and great saphenous vein
▪ Drains into the external iliac vein

Front 54

perforating veins

Back 54

connect the superficial to the deep veins of the thigh

Front 55

great saphenous vein

Back 55

o Courses along medial aspect of thigh
o Enters saphenous opening in the fascia lata to drain into femoral vein

Front 56

femoral triangle borders

Back 56

o Inguinal ligament (superiorly)
o Adductor longus (medially)
o Sartorius (laterally)

Front 57

femoral triangle contents

Back 57

o "NAVEL" (lateral to medial: Nerve, Artery, Vein, Empty space, Lymph)
o Femoral nerve (and its branches)
o Femoral sheath (AVEL)

Front 58

femoral sheath

Back 58

o Fascial tube enclosing the femoral vessels and femoral canal
o Does not enclose the femoral nerve
o Divided into 3 compartments:
• Lateral contains the femoral artery
• Intermediate contains the femoral vein
• Medial contains the femoral canal

Front 59

femoral ring

Back 59

o The proximal opening of the femoral canal
o area of weakness where femoral hernias can occur
o Normally, the ring is closed by extraperitoneal fatty tissue, and this fatty tissue is overlaid by parietal peritoneum

Front 60

femoral hernia

Back 60

o Abdominal viscera (loop of intestine) can protrude through the femoral ring into the femoral canal, forming a femoral hernia
o lies in the femoral triangle, medial to the femoral vein, lateral to the lacunar ligament, and inferior to the inguinal ligament
o may emerge through the saphenous opening into the subcutaneous tissue of the thigh
o occur more frequently in females

Front 61

femoral canal

Back 61

o contains loose connective tissue, fat, lymphatic vessels
o Primary function is to allow expansion of femoral vein when venous return from the lower limb is increased (e.g., during strenuous activity)

Front 62

femoral artery

Back 62

• Primary source of blood to lower extremity
• Continuation of external iliac artery (change names at inguinal ligament)
• Supplies anterior and medial compartments of thigh

Front 63

femoral pulse

Back 63

can be felt just inferior to the midpoint of the inguinal ligament, with patient in supine position. Compression at this location will stop blood flow through the femoral artery.

Front 64

deep artery of thigh

Back 64

• Largest branch of femoral artery
• Supplies posterior compartment of thigh

Front 65

lateral and medial circumflex femoral arteries

Back 65

o Typically branches of the deep artery of the thigh (can be branches of the femoral a.)
o Medial circumflex femoral a. supplies most of the blood to the head and neck of the femur
o Lateral circumflex femoral a. supplies muscles on the lateral aspect of thigh

Front 66

obturator artery

Back 66

• Branch of the internal iliac artery
• Passes through obturator canal to enter medial compartment of the thigh
• Supplies medial and posterior compartments of thigh

Front 67

adductor canal boundaries

Back 67

o Vastus medialis (anterolateral)
o Adductor longus and magnus (posterior)
o Sartorius (medial)

Front 68

adductor canal contents

Back 68

o Femoral artery
o Femoral vein
o Saphenous nerve (terminal branch of femoral n.)

Front 69

adductor canal

Back 69

• A fascial tunnel running from the apex of the femoral triangle to the adductor hiatus in the tendon of adductor magnus
• Provides a passage for femoral vessels to reach the popliteal fossa on the posterior aspect of the knee, where they become popliteal vessels