anterior compartment of the thigh

Question 1

Iliopsoas

Answer 1

origination: The psoas major originates from the lumbar vertebrae, and the iliacus originates from the iliac fossa of the pelvis.
insertion: They insert together onto the lesser trochanter of the femur.
Actions: Flexion of the the thigh at the hip joint.
Innervation: The psoas major is innervated by anterior rami of L1-3, while the iliacus is innervated by the femoral nerve.
(These muscles arise in the pelvis and pass under the inguinal ligament)

Question 2

Quadriceps Femoris

Answer 2

The quadriceps femoris consists of the three vastus muscles and the rectus femoris.
It is one of the most powerful muscles in the body.

The four muscles collectively insert onto the patella via the quadriceps tendon. The patella, in turn, is attached to the tibial tuberosity by the patella ligament.

Question 3

Vastus Lateralis

Answer 3

Originates from the greater trochanter and the lateral lip of linea aspera of the femur.
Actions: Extension of the knee joint. It has a secondary function of stabilising the patella.
Innervation: Femoral nerve.

Question 4

Vastus Intermedius

Answer 4

Originates from the anterior and lateral surfaces of the femoral shaft.
Actions: Extension of the knee joint. It has a secondary function of stabilising the patella.
Innervation: Femoral nerve.

Question 5

Vastus Medialis

Answer 5

Originates from the intertrochanteric line and medial lip of the linea aspera of the femur.
Actions: Extension of the knee joint. It has a secondary function of stabilising the patella.
Innervation: Femoral nerve.

Question 6

Rectus Femoris

Answer 6

Originates from the anterior inferior iliac spine and the ilium of the pelvis.
It attaches to the patella via the quadriceps femoris tendon.
Actions: Extension of the knee joint and flexion of the hip joint (it is the only muscle of the quadriceps group to cross both the hip and knee joints).
Innervation: Femoral nerve.

Question 7

The sartorius

Answer 7

The sartorius is the longest muscle in the body. It is long and thin, running across the thigh in a inferomedial direction.
Originates from the anterior superior iliac spine, and attaches to the superior, medial surface of the tibia.
Actions: At the hip joint, it is a flexor, abductor and lateral rotator. At the knee joint, it is also a flexor.
Innervation: Femoral nerve.

Question 8

Pectineus(medial compartment)

Answer 8

The pectineus is a flat, quadrangular-shaped muscle which contributes to the floor of the femoral triangle.

Originates from the pectineal line of the pubis bone.
It inserts onto the pectineal line on the posterior aspect of the femur, immediately inferior to the lesser trochanter.
Actions: Adduction and flexion at the hip joint.
Innervation: obturator nerve.