Semimembranosus Flashcards

Explore semimembranosus anatomy, including its ischial origin, tibial insertion, tibial nerve supply, hip extension, knee flexion, and clinical relevance.

Card 1 of 28Question

Which compartment of the thigh contains the semimembranosus?

The posterior compartment of the thigh.

In This Section

1. Which compartment of the thigh contains the semimembranosus?

The posterior compartment of the thigh.

2. Which muscle group includes the semimembranosus?

The hamstring muscle group.

3. What is the proximal bony attachment of semimembranosus?

The superolateral aspect of the ischial tuberosity.

4. What distinctive structure characterizes the proximal portion of semimembranosus?

A broad, flattened membranous tendon.

5. Where is the principal distal insertion of semimembranosus?

The posterior aspect of the medial condyle of the tibia.

6. Which ligament receives a reflected expansion from the semimembranosus tendon?

The oblique popliteal ligament.

7. Which part of the knee joint capsule is reinforced by semimembranosus tendon expansions?

The posterior fibrous capsule of the knee joint.

8. Which nerve supplies the semimembranosus?

The tibial division of the sciatic nerve.

9. Which spinal nerve roots are primarily associated with semimembranosus innervation?

L5, S1, and S2.

10. Which artery provides a major blood supply to semimembranosus?

The profunda femoris artery through its perforating branches.

11. Which additional artery can contribute to the proximal blood supply of semimembranosus?

The inferior gluteal artery.

12. Which venous system primarily drains the semimembranosus in the thigh?

Muscular tributaries of the profunda femoris venous system.

13. Which two joints are crossed by semimembranosus?

The hip and knee joints.

14. What action does semimembranosus produce at the hip?

Extension of the thigh at the hip joint.

15. What is the primary action of semimembranosus at the knee?

Flexion of the leg at the knee joint.

16. Which rotational movement is produced by semimembranosus when the knee is flexed?

Medial rotation of the leg relative to the thigh.

17. How can semimembranosus assist in unlocking the fully extended knee?

By producing medial rotation of the tibia when the foot is free.

18. Which hamstring muscle lies superficial to much of semimembranosus?

Semitendinosus.

19. What is the position of semimembranosus relative to biceps femoris?

Semimembranosus lies medially, while biceps femoris lies laterally.

20. Which boundary of the popliteal fossa is formed by semimembranosus?

The superomedial boundary, together with semitendinosus.

21. Which bursa lies between the semimembranosus tendon and the medial head of gastrocnemius?

The gastrocnemius-semimembranosus bursa.

22. Which common posterior knee swelling can arise from distension of the gastrocnemius-semimembranosus bursa?

A Baker cyst, also called a popliteal cyst.

23. Which part of the medial meniscus receives attachments from semimembranosus expansions?

The posterior horn and adjacent posteromedial capsular structures.

24. How does semimembranosus contribute to knee stability during flexion?

It helps control tibial rotation and supports the posteromedial knee structures.

25. How does semimembranosus function during the terminal swing phase of gait?

It contracts eccentrically to decelerate knee extension and hip flexion.

26. How can semimembranosus strength be assessed clinically?

By testing resisted knee flexion with the leg medially rotated.

27. What movement deficit may follow injury to the tibial division of the sciatic nerve affecting semimembranosus?

Weakness of knee flexion and medial rotation of the flexed leg.

28. Which imaging modality is particularly useful for evaluating semimembranosus tendon tears?

Magnetic resonance imaging (MRI).