Nerves of the lower extremity

Question 1

lumbar plexus

Answer 1

• this is formed from the anterior rami of spinal nerves L1-L4
• this is what contributes the femoral nerve and obturator nerve

Question 2

sacral plexuses

Answer 2

this is formed from the anterior rami of spinal nerves L4-S4

• this is what contributes to the superior gluteal nerve, the inferior gluteal nerve and the sciatic nerve

Question 3

what exits the greater sciatic foramen superior to the piriformis

Answer 3

• the superior gluteal nerve

- the superior gluteal artery

Question 4

superior gluteal nerve

Answer 4

• this innervates the gluteus medius, the gluteus minimus, and the tensor fasciae latae
• exits the greater sciatic foramen superior to the piriformis

Question 5

inferior gluteal nerve

Answer 5

this innervates the gluteus maximus

• exits the greater sciatic foramen inferior to the piriformis

Question 6

what exits the greater sciatic foramen inferior to the piriformis

Answer 6

• the inferior gluteal nerve

- the inferior gluteal artery

Question 7

obturator nerve

Answer 7

• innervates all adductors muscles
• this innervates all of the muscles in the medial thigh (some may have other innervation as well but all at least have this nerve)

-cutaneous innervation: is the medial thigh region

Question 8

femoral triangle

Answer 8

this is an important landmark that has the femoral artery, vein, and nerve traveling within the femoral sheath

boundaries:
inguinal ligament superiorly
sartorius muscle laterally
adductor longus muscle medially

Question 9

femoral nerve

Answer 9

• this comes from the lumbar plexus
• innervates anterior thigh muscles
• has partial innervation of the pectineus along with the obturator

cutaneous innervation: anterior thigh and medial leg

Question 10

where is the adductor hiatus

Answer 10

this is in the adductor magnus

-this is what the femoral artery travels through to become the popliteal artery

Question 11

sciatic nerve

Answer 11

• this is a major branch of the sacral plexus that exits the greater sciatic foramen inferior to the piriformis muscle
• this is actually two nerves that are wrapped in a common sheath (the tibial and common fibular nerve)

Question 12

tibial division of sciatic

Answer 12

• this innervates the long head of the biceps femoris, the semimembranosus, the semitendinosus, and the hamstring part of the adductor magnus

this innervates all but one of the muscles of the thigh

Question 13

tibial nerve

Answer 13

• this is one of the two nerves that the sciatic nerve branches into at the popliteal fossa
• this is innervating the superficial and deep posterior compartment muscles
• this runs posterior to the medial malleolus on the ankle and then turns into the medial and lateral plantar nerves

Question 14

common fibular nerve

Answer 14

• this is one of the two nerves that the sciatic nerve branches into at the popliteal fossa
• this innervates the short head of the biceps femoris
• this branches into the superficial fibular nerve and the deep fibular nerve
• the two branches work together to innervate the skin of the lateral and anterior leg and dorsal foot

Question 15

superficial fibular nerve

Answer 15

• this is innervating the lateral compartment muscles of the leg

Question 16

deep fibular nerve

Answer 16

this is innervating the anterior compartment muscles

Question 17

piriformis syndrome

Answer 17

this is when the sciatic nerve (or a portion of the sciatic nerve) pierces the piriformis muscle

• this muscle contracts alot and this can put pressure on the nerve and lead to a pain that travels down the leg due to constriction of the sciatic nerve
• if only one part of the nerve is piercing the muscle, then the individual will only feel pain where that portion is innervating

Question 18

medial and lateral plantar nerves

Answer 18

the tibial nerve continues down and divides into the medial and lateral plantar nerves