Lower Limb - Anterior Thigh Muscles (1)

Question 1

Briefly describe the pectineus muscle.

Answer 1

Pectineus is a small muscle.
Proximal attachment: superior pubic ramus.
Distal attachment: femur
Adducts and flexes thigh.

Question 2

Name the proximal and distal attachments of psoas major.

Answer 2

Proximal: Transverse processes of T12 and all lumbar vertebrae
Distal: Lesser trochanter of femur

Question 3

Name the proximal and distal attachments of iliacus.

Answer 3

Proximal: iliac crest and iliac fossa of the hip bone
Distal: Lesser trochanter of femur

Question 4

Describe the chief flexor of the thigh.

Answer 4

The iliopsoas is the chief flexor of the thigh. It is formed by the psoas major and the iliacus muscles.

Question 5

Name the proximal and distal attachments of sartorius.

Answer 5

Proximal: ASIS
Distal: Tibia, on the superior medial surface.

Question 6

What is the action of sartorius?

Answer 6

Sartorius is not a strong muscle, it is mainly a synergist. It brings the lower legs into the cross-legged position.

Question 7

Name the four muscles that make up the quadriceps femoris.

Answer 7

Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius

Question 8

Name the proximal attachment of rectus femoris.

Answer 8

The Anterior Inferior Iliac Spine, which is at the ilium, just superior to acetabulum.

Question 9

Name the proximal attachment of the three vastus heads of the quadriceps.

Answer 9

All come from the femur.
Vastus lateralis: greater trochanter
Vastus medialis: medial side of femur
Vastus intermedius: shaft of femur

Question 10

Describe the distal attachment of the quadriceps muscle.

Answer 10

All four heads converge to form the quadriceps tendon, which inserts at the patella, continuing over the patella to the tibial tuberosity as the patellar ligament. The medial and lateral vasti also attach to the tibia via the medial and lateral patellar retinacula (additional tendons)

Question 11

What is the innervation to most of the anterior thigh muscles?

Answer 11

Femoral nerve. (all muscles except for psoas major and minor, which are innervated by lumbar nerves L1-L2-L3)

Question 12

What are the actions of rectus femoris?

Answer 12

Rectus femoris crosses two joints, which means that it can flex the thigh AND extend the leg.