lower limb : innervation

Question 1

what does the sciatic nerve innervate?

Answer 1

motor : all myscles in posterior copartment of thigh and part of the aductor magnus attached to ischium. all muscles in the leg and foot.
sensory: skin over lateral side of leg and foot, and over the sole and dorsal of foot

Question 2

what does the superior gluteal nerve innervate?

Answer 2

(L4-S1)

muscles of the gluteal region (medius, minimus, tensor fasciae latae)

Question 3

what does the inferior gluteal nerve innervate?

Answer 3

(L5-S2)

gluteus maximus

Question 4

what does the lateral cutaneous nerve of the thigh innervate?

Answer 4

sensory - parietal peritoneum in illiac fossa, skin over anterolateral and posterior thigh.

Question 5

what does the posterior cutaneous nerve of the thigh innervate?

Answer 5

sensory -skin over perineum and posterior thigh and leg

Question 6

what innervates quadratus femoris? what else does it innervate

Answer 6

nerve to quadratus femoris, also gemellus inferior

Question 7

what innervates the obturator internus and what else does it innervate?

Answer 7

nerve to obturator internus. also gemellus superior

Question 8

what does the perforating cutaneous nerve innervate?

Answer 8

sensory - skin over media aspect of gluteal fold

Question 9

what does the ilio-inguinal nerve innervate?

Answer 9

(L1)
motor - muscles of abdominal wall.
sensory- skin, anteromedial part of upper thigh and adjacent skin of perineum

Question 10

what does genitofemoral nerve innervate?

Answer 10

(L1-L2)
motor - no motor function in lower limb, but genital branch innervates cremaster muscle in the wall of the spermatic cord in men
sensory - femoral branch innervates skin on anterior central part of upper thigh. the genital branch innervates skin in anterior part of perineum (anterior scrotum in men, and mons pubis and anterior labia majora in women)

Question 11

what does the femoral nerve innervate?

Answer 11

(L2-L4)
motor - all muscles in the anterior compartment of the thigh.; quadriceps (vastus laterals, intermdialis, medialis), sartorius, illiacus, psoas major, and pectineus muscles. in the abdomen it branches to nerves that supply the illiacus and pectineus.
sensory - skin over the anteriomedial thigh , anteromedial knee(anterior cutaneous nerves) , medial side of leg, and medial side of the foot (saphenous nerve)

Question 12

what does the obturator nerve innervate?

Answer 12

(L2-L4)
motor- all muscles in the medial compartment of the thigh (except pectineus and part of adductor magnus attached to the ischium) - graliis, obturator exernus, adductor magnus, brevis and longus muscles.

sensory - skin over upper medial aspect of thigh

Question 13

what forms the lumbar plexus? what are its major terminal nerves

Answer 13

anterior rami T12-L4.
major terminal nerves; lateral femoral cutaneous nerve, genitofemoral nerve, femoral nerve
other nerves : iliohypogastric nerve, ilioinguinal nerve, obturator nerve

Question 14

what does the iliohypogastric nerve innervate?

Answer 14

(t12 and L1)
-external and internal oblique and transverse abdominis muscles. receives sensory info from skin over inferior abdomen and buttox

Question 15

what are the terminal nerves of the sacral plexus?

Answer 15

(L40S4)
part of L4 and L5 make lumbosacral trunk, which joins sacral plexus.
five major: superior gluteal nerve, inferior gluteal nerve, sciatic nerve, posterior femoral cutaneous nerve, and branches of sciatic nerve (TIBIAL NERVE AND FIBULAR NERVE)

Question 16

what are the branches of the sciatic nerve?

Answer 16

fibular and tibial

Question 17

what does the tibial nerve innervate?

Answer 17

flexors of knee and plantarflexors of ankle. flexors of toes

skin- over posterior surface of leg and plantar of foot

Question 18

what does the fibular nerve innervate?

Answer 18

short head of biceps femoris muscle, fibularis longus, fibularis brevis, tibialis anterior uscles, and extensors of toes.
sensory- anterior of leg and skin over lateral of foot through the sural nerve (also a branch of tibial nerve)

Question 19

what innervates the skin of upper, medial of thigh ?

Answer 19

obturator nerve.
also - innervates muscles in the medial compartment of thigh EXCEPT for pectineus and part of adductor magnus
(obturator externus, adductor brevis/longus, gracilis, part of adductor magnus)

Question 20

sensory - what does the obturator nerve innervate?

Answer 20

upper, medial thigh

Question 21

sensory- what does the lateral cutaneous nerve of thigh innervate?

Answer 21

anterolateral and posterolateral of thigh

Question 22

sensory -what does the femoral nerve innervate?

Answer 22

anterior cutaneous part innervates anterior thigh and anterolateral knee.
saphenous part innervates the anteromedial lower leg and posteromedial lower leg.

Question 23

sensory - what does the common fibular nerve innervate?

Answer 23

lateral cutaneous part - lateral anterior/posterior knee to above ankle.
superficial branch - anterior/lateral lower leg and dorsal of food (except toes)

Question 24

sensory - what innervates the ankle?

Answer 24

lateral side is tibial nerve (sural nerve) which also gets lateral of foot.
superficial branch gets anterior ankle and dorsal of foot
femoral/saphenous part gets medial ankle.
tibail nerve, medial calcaneal branch gets the heel

Question 25

sensory - what innervates plantar foot?

Answer 25

medial plantar (1-half of 4th toes) and medial
lateral plantar nerve half of 4th toe and 5th, lateral
sural nerve - lateral edge
saphenous nerve. - medial edge
tibial nerve - heel

(lateral and medial are terminal of tibial nerve)