TBL8 - Posterior Thigh Flashcards
What are three posterior thigh muscles that attach proximally to the ischial tuberosity? What part of another muscle attaches proximally to the ischial tuberosity? Where does the short head of the biceps femoris attach to proximally?
1) The semitendinosus, semimembranosus, and long head of the biceps femoris attach proximally to the ischial tuberosity
2) The tuberosity is the proximal attachment site for the hamstring portion of the adductor magnus
3) The short head of the biceps femoris attaches proximally to the linea aspera
Where do the semitendinosus and semimembranosus attach to distally? Where does the biceps femoris (long and short heads) attach to distally? What innervates the semitendinosus, semimembranosus, and two heads of the biceps femoris? What is the synergistic function of these muscles?
1) The semitendinosus and semimembranosus muscles attach distally to the superior tibia
2) The common distal attachment for the biceps femoris is the head of the fibula
3) The tibial division of sciatic nerve part of tibia (L5, S1, S2) innervates the semitendinosus, semimembranosus and the long head of the biceps femoris
4) The common fibular division of sciatic nerve (L5, S1, S2) innervates the short head of the biceps femoris
5) The muscles synergistically extend the thigh and flex the leg
What forms the pes anserinus (goose’s foot)? What separates the tendons from the tibia? What is a common source of medial knee pain in runners?
1) On the superomedial tibia, tendons of the semitendinosus, sartorius, and gracilis muscles form the pes anserinus (goose’s foot)
2) The tendons are separated from the tibia by the anserine bursa
3) Anserine bursitis is a common source of medial knee pain in runners
Where do the superior gluteal nerve and artery emerge from? Where do the inferior gluteal nerve and artery emerge from?
1) The superior gluteal nerve and artery emerge from the pelvis in the greater sciatic foramen superior to the piriformis
2) The inferior gluteal nerve and artery traverse the foramen inferior to the muscle
Where does the sciatic nerve emerge from? What is characteristic of the sciatic nerve?
1) The sciatic nerve emerges from the pelvis in the greater sciatic foramen inferior to the piriformis
2) The sciatic nerve, which arises from spinal cord segments L4-S3, is the largest nerve in the body
What nerves does the sciatic nerve consist of? Where do these nerves separate? What innervates the muscles of the anterior and lateral leg?
1) The sciatic nerve consists of the loosely bound common fibular (peroneal) and tibial nerves that separate in the distal thigh
2) The terminal branches of the common fibular (peroneal) nerve innervate muscles of the anterior and lateral leg
Why are both heads of the biceps femoris not always paralyzed after nerve injury in the posterior thigh?
Because each of the two heads of the biceps femoris has a different nerve supply (long head - tibial nerve (L5-S2); short head - common fibular nerve (L5-S2)), a wound in the posterior thigh with nerve injury may paralyze one head and not the other
Why does complete section of the sciatic nerve, although uncommon, cause loss of ipsilateral lower limb function?
1) Complete section of the sciatic nerve is uncommon; however, when it occurs, the leg is useless because extension of the hip is impaired, as is flexion of the leg
2) All ankle and foot movements are also lost
Where does the posterior cutaneous nerve to the thigh travel?
The posterior cutaneous nerve to the thigh courses through the greater sciatic foramen medial to the sciatic nerve
What are the gluteal arteries branches of? What do they supply? What does the deep artery of the thigh supply?
1) The gluteal arteries are branches of the internal iliac artery
2) They supply the muscles of the gluteal region
3) The deep artery of the thigh supplies the hamstring muscles
