Gluteal Region and Posterior Thigh Flashcards
What are the 9 muscles of the gluteal region?
Gluteus maximus Gluteus medius Gluteus minimus Tensor fasciae latae Piriformis Obturator internus superior gemellus inferior gemellus quadratus femoris
What is the nerve supply and action of the gluteus maximus?**
Supplied by the inferior gluteal nerve
-extends and laterally rotates the femur at the hip joint
-helps maintain kneejoint in extension
=note only called into action during rapid and powerful extension, not during normal gait. used going upstairs, climbing etc
What is the nerve supply of the gluteus medius nerve, and what is its function?
Supplied by the superior gluteal nerve
-abducts and medially rotates the femur at the hip joint
What is the nerve supply of the gluteus minimus, and what is its action?
Is supplied by the superior gluteal nerve
-abducts and medially rotates femur at hip joint
What are the 2 chief abducts of the thigh?**
gluteus medius and gluteus minimus
-note that they also steady the pelvis while walking
What occurs if the gluteus medius and minimus are paralyzed unilaterally?
results in Trendelenburg gait
Pelvis is dropped on the unaffected side and there is lateral flexion of the trunk towards the paralyzed side in order to compensate for the shift in center of gravity
What is the nerve supply of the tensor fasciae latae, and what is its action?
supplied by the superior gluteal nerve
flexes and abducts the femur at the hip joint
-The tensor fasciae latae (along with the gluteus maximus) insert in the iliotibial tract, and assist in stabilizing the knee in extension; also help stabilize hip joint
What is the nerve supply of the piriformis, and what is its action?
supplied by the nerve to the piriformis
Laterally rotates the femur at the hip joint
What are the 4 muscles below the piriformis?
Obturator internus superior gemellus inferior gemellus quadratus femoris =they are all pure lateral rotators
What is the nerve supply and action of the obturator internus?
Supplied by the nerve to obturator internus
laterally rotates the femur at the hip joint
What is the nerve supply and action of the superior gemellus?
nerve to obturator internus
laterally rotates the femur at the hip joint
What is the nerve supply and action of the inferior gemellus?
supplied by the nerve to the quadratus femoris
laterally rotates the femur at the hip joint
What is the nerve supply and action of the quadratus femoris?
supplied by the nerve to the quadratus femoris
laterally rotates the femur at the hip joint
On the anterior surface of what muscle does the sacral plexus lie?
On the anterior surface of the piriformis muscle
What are the 7 major branches of the sacral plexus? Through which foramen do they all leave the pelvis?
Sciatic nerve (L4 - S3) Posterior cutaneous nerve of the thigh Superior gluteal nerve Inferior gluteal nerve Nerve to the quadratus femoris Pudendal nerve Nerve to obturator internus
All leave the pelvis through the greater sciatic foramen
How does the sciatic nerve emerge from the pelvis? What muscle does it reach?
Through greater sciatic foramen below the piriformis muscle
Passes posterior surface of superior gemellus, obturator internus, inferior gemellus, and quadratus femoris to reach back of adductor magnus
What are the 2 nerves contained in the sciatic nerve?
Tibial nerve
Common fibular nerve
What does the posterior cutaneous nerve of the thigh supply?
Supplies cutaneous to the posterior thigh (to buttocks, scrotum, labia majora)
What does the superior gluteal nerve supply?
Supplies the gluteus medius, gluteus minimus, and tensor fasciae latae muscles
What does the inferior gluteal nerve supply?
Supplies the gluteus maximus muscle
What does the quadratus femoris nerve supply?
Supplies the quadratus femoris and inferior gemellus
What does the pudendal nerve supply?
Supplies the perineum
What does the obturator internus nerve supply?
Supplies obturator internus and superior gemellus
Which branches of the sacral plexus emerge from the pelvis above, and which below, the piriformis muscle?
Above piriformis: -Superior gluteal nerve Below piriformis: -sciatic nerve -posterior cuteanous nerve of the thigh -inferior gluteal nerve -nerve to quadratus femoris -pudendal nerve and nerve to obturator internus
What muscles are contained in the posterior compartment of the thigh? What is the blood and nerve supply of the posterior compartment
Biceps femoris
Semitendinosus
Semimembranosus
Hamstring portion of adductor magnus
Blood supply: branches of profunda femoris artery (perforating branches)
Nerve supply: tibial division of the sciatic nerve
What is the group action of the posterior compartment of the thigh? What do all of these muscles attach to?
Extension of the thigh and flexion of the leg (but the hamstring portion of the adductor magnus does NOT cause flexion of the leg)
-all of these muscles attach to the ischial tuberosity*
What is the only muscle in the posterior compartment that does not cause flexion of the leg?**
Hamstring portion of the adductor magnus
because it does NOT cross the knee joint**
What compartment is the biceps femoris in, what is the nerve supply to the long and short head, and what is its action?
In posterior compartment
tibial nerve supplies long head
common fibular nerve supplies short head
-extends femur at hip joint, flexes and laterally rotates the leg at the knee joint
What compartment is the semitendinosus muscle in, what is its nerve supply and its action?
in the posterior compartment
supplied by tibial nerve
extends femur at hip joint, flexes and medially rotates the leg at the knee joint
What compartment is the semimembranosus muscle in, what is its nerve supply and what is its action?
in the posterior compartment
supplied by the tibial nerve
extends femur at hip joint, flexes and medially rotates the leg at the knee joint
What does the heavy lateral expansion of the semimembranosus muscle form?
Oblique popliteal ligament
What tears in hamstring injuries?
The proximal tendinous attachments to the ischial tuberosity
What 3 muscles make up the per anserinus tendons? What nerve are each of them supplied by?
Sartorius - femoral nerve
Gracilus - obturator nerve
Semitendinosus - tibial nerve
What is the group action of the per anserinus tendons, which side of the knee joint are they on?
They all flex the knee joint
All provide additional support to knee joint
on medial side of knee joint
What are the superficial contents of the popliteal fossa?
Fat
Small saphenous vein
3 cutaneous nerves
What are the deep contents of the popliteal fossa?
Popliteal artery and vein
Tibial and common fibular nerves
popliteal lymph nodes
What is contained in the center of the fossa (from medial to lateral and deep to superficial)?
Deep -> Superficial and Medial -> Lateral
- Popliteal artery
- Popliteal vein
- tibial nerve
What artery is the popliteal artery a direct continuation of?
Femoral artery after passing through adductor hiatus
What 2 arteries does the popliteal artery divide into, and where?
At the lower border of the popliteus muscle, divides into:
- anterior tibial artery
- posterior tibial artery
What artery is the main supply to the knee joint?
Genicular branches of the popliteal artery
What vein receives the small saphenous vein?
popliteal vein
