Anatomy 2: Anterior & Medial Thigh

Question 1

Identify the compartments of the thigh, and know their contents.

Answer 1

a. Anterior
- i. Main extensors of knee and flexors of thigh.
- ii. Innervated by: Femoral nerve (ventral rami L2-4)
- iii. Blood supply by Femoral artery and perforating branches from deep artery of thigh

b. Medial
- i. Main action: adduction of thigh
- ii. Innervation: Obturator nerve
- iii. Blood supply: Obturator artery

c. Posterior:
- i. Flexion of leg and extension of hip
- ii. Innervation = sciatic nerve
- iii. Blood supply: deep artery of thigh

Question 2

Identify the muscles of the medial compartment of the tight; know their origins, insertions, actions, relative locations, and innervation.

Answer 2

*Gracilis
Origin: body and inferior ramus of pubus Insertion: pes anserinus
Adduction, flexion and medial rotation of thigh
Obturator (L2-3)
Deep art of thigh

*Adductor longus
Origin: Body of pubis inferior to crest
Insertion: middle third of linea aspera
Adducts thigh
Anterior division of obturator (L2-4)
Deep art of thigh

*Adductor brevis
Origin: Body and inferior ramus of pubis
Insertion: pectineal line and proximal linea aspera
Adducts thigh, minor flexor
Anterior division of obturator
Deep art of thigh

*Adductor magnus adductor part
Origin: inferior ramus of pubus and ischium
Insertion: gluteal tuberosity, linea aspera, medial supracondylar line
Adduction of thigh
Posterior division of obturator (L2-4)
Obturator, deep art of thigh, fem art

*Adductor magnus *ischiocondylar part*
Origin: ischial tuberosity Insertion: adductor tubercle of femur
Extends thigh
Tibial part of sciatic (T4)
Deep art of thigh

Obturator externus
Origin: obturator membrane and margins of obturator foramen
Insertion: trochanteric fossa
Lateral rotation of thigh and stabilization of femur in acetabulum
Obturator nerve (L3-4)
Obturator artery

Question 3

Identify the muscles of the anterior compartment of the thigh; know their origins, insertion, actions, relative locations, and innervation.

Answer 3

*Rectus femoris	
Origin: AIIS and groove above acetabulum
Insertion: Tibial tuberosity	
Flexion of thigh, Extension of hip	
Femoral nerve	
Fem art

*Vastus lateralis	
Origin: Greater trochanter and lateral lip of linea aspera
Insertion: Tibial tuberosity	
Extension of knee (LARGEST OF QUADS)	
Femoral nerve	
Deep artery of thigh

*Vastus medialis	
Origin: Medial lip of linea aspera
Insertion: tibial tuberosity	
Extensor of leg	
Femoral nerve	
Fem art

*Vastus intermedius	
Origin: anterior surface of femoral shaft
Insertion: tibial tuberosity	
Extension of leg	
Femoral nerve	
Fem art AND perf. Branches of deep thigh

*Sartorius
Origin: ASIS
Insertion: Superior medial tibia (pes anserinus)
Flexion, abduction and lateral rotation of hip. Flexion of knee
Femoral
Fem art

*Iliopsoas	
Origin: Iliacus and psoas
Insertion: lesser trochanter	
Flexion of thigh	
Direct ventral rami and femoral nerve	

*Pectineus	
Origin: Pectineal line of pubus
Insertion: pectineal line of femur	
Adducts, flexes, medially rotates	
Femoral nerve	
Medial circumflex femoral

Question 4

Describe the course and branches of the femoral artery in the thigh.

Answer 4

a. Superficial circumflex iliac
b. Superficial epigastric
c. Superficial external pudendal
d. Deep external pudendal
e. Deep artery of thigh
–i. Lateral circumflex femoral (ascending, transverse and descending branches)
–ii. Medial circumflex femoral (supplies femur) usually 5 branches:
—1) Small = anastamoses with obturator
—2) Superficial branch to pectineus and adductor longus
—3) Ascending branch - adductor brevis, magnus and obturator externus
—4) Transverse/descending to quadrator femoris and adductor magnus. Part of cruciate
anastomoses.
—5) Deep branch - anastamose with descending branch of LCF
–iii. Perforating branches
f. Descending genicular artery

Question 5

Describe the femoral triangle, its boundaries, and its contents.

Answer 5

a. Boundaries
- i. Base = superior margin. Inguinal ligament
- ii. Medial border = adductor longus
- iii. Lateral border = sartorius
- iv. Apex = adductor magnus + sartorius
- v. Floor = iliopsoas and pectineus
- vi. Roof = cribiform fascia

b. Contents
- i. NAVL (lateral to medial)

Question 6

Describe the adductor canal, its boundaries, and its contents.

Answer 6

a. Boundaries
- i. Anterolateral - vastus medialis
- ii. Medial border/roof = sartorius
- iii. Posterior border - adductor longus and magnus

b. Content
- i. Femoral artery/vein, saphenous nerve, nerve to vastus medialis.

Question 7

Describe the course and branches of the femoral and obturator nerve in the thigh.

Answer 7

a. Femoral
- i. Supplies iliacus and pectineus muscles. Divides anterior and medial branches
- -1) Anterior cutaneous branches
- -2) Numerous motor branches (quadriceps femoris muscles, sartorius muscles)
- -3) Skin on medial side of leg and foot via saphenous nerve

b. Obturator
- i. Originates from lumbar plexus (L2-4)
- ii. Supplies most adductor muscles on medial portion of thigh
- iii. Anterior and posterior branches divided by adductor brevis
- -1) Anterior branch = gracilis, adductor longus and adductor brevis, as well as cutaneous skin of med. Thigh
- -2) Posterior branches = obturator externus, adductor brevis, adductor magnus.

Question 8

Which muscles are responsible for flexion of the hip?

Answer 8

Iliopsoas, tensor fasciae latae, rectus femoris, adductors, sartorius, pecineus, gracilis.