2b - Muscles In the Anterior Thigh

Question 1

Iliacus - Origin, Insertion, Action(s), and Innervation

Answer 1

Origin: Iliac fossa and ala of sacrum
Insertion: Lesser trochanter of femur via iliopsoas tendon
Primary action: Prime mover in thigh flexion and flexing trunk
Innervation: Femoral

Question 2

Psoas major - Origin, Insertion, Action(s), and Innervation

Answer 2

Origin: Fleshy slips from transvere processes, bodies, and discs of T12 - L5 vertebrae
Insertion: Lesser trochanter of femur via iliopsoas tendon
Primary action: Thigh flexion and trunk flexion.
Innervation: Femoral

Question 3

Tensor fasciae latae - Origin, Insertion, Action(s), and Innervation

Answer 3

Origin: Anterior aspect of iliac crest and anterior superior iliac spine
Insertion: Iliotibial tract
Primary action: Steadies trunk on thigh
Other action(s): Flexes, abducts, and medially rotates thigh
Innervation: Superior gluteal

Question 4

Sartorius - Origin, Insertion, Action(s), and Innervation

Answer 4

Origin: Anterior superior iliac spine
Insertion: Winds around medial aspect of knee and inserts into medial aspect of proximal tibia
Primary action: Flexes, abducts, and laterally rotates thigh. Flexes leg.
Other action(s): Helps produce the cross-legged position
Innervation: Femoral

Question 5

What four muscles make up the Quadriceps femoris?

Answer 5

The Rectus Femoris, Vastus Lateralis, Vastus Medialis, and Vastus Intermedius.

Question 6

Rectus femoris - Origin, Insertion, Action(s), and Innervation

Answer 6

Origin: Anterior inferior iliac spine and superior margin of acetabulum
Insertion: Patella and tibial tuberosity via patellar ligament
Primary action: Extends knee and flexes thigh
Innervation: Femoral

Question 7

Vastus lateralis - Origin, Insertion, Action(s), and Innervation

Answer 7

Origin: Greater trochanter, intertrochanteric line, and linea aspera
Insertion: Patella and tibial tuberosity via patellar ligament
Primary action: Extends knee
Innervation: Femoral

Question 8

Vastus intermedius - Origin, Insertion, Action(s), and Innervation

Answer 8

Origin: Anterior and lateral surfaces of shaft of femur
Insertion: Patella and tibial tuberosity via patellar ligament
Primary action: Extends knee
Innervation: Femoral

Question 9

Vastus medialis - Origin, Insertion, Action(s), and Innervation

Answer 9

Origin: intertrochanteric line, linea aspera, and medial supracondylar line
Insertion: Patella and tibial tuberosity via patellar ligament
Primary action: Extends knee and helps stabilize patella
Innervation: Femoral