Lumbar and Sacral Plexus

Question 1

Obturator nerve (L2-L4) supply

Motor and sensory supply

Answer 1

• skin medial thigh
  ; hip joint.
• articular branches to the hip and knee joint
• supply most of the adductor muscles
  and - gracilis, obturator externus,

Question 2

Femoral nerve (L2-L4) motor and cutaneous supply?

Answer 2

• supply the quadriceps muscles
• as well as sending muscular branches to the illicit and pectineus muscle.
• skin to the medial leg and foot
• provide articular branches to the knee joint.

Question 3

if someone had impact injuries to the lateral side of the leg, what nerve should we be concern about?

Answer 3

Common Peroneal Nerve because it wraps around the fibular head and can be crushed.

Question 4

Genitofemoral nerve supply?

and its divisions

Answer 4

• genital and femoral division
• skin of proximal medial thigh
• skin of the anterior scrotum for males or labia majora for females, male cremaster muscle

Question 5

Nerve supply of the lateral cutaneous nerve of the thigh?

Answer 5

• L2-L3
• L2-L3
• no muscular branch
• supply the skin on the antero-lateral thigh to the knee…
• anterior & posterior branches

Journey:
- pass in front of the illicit muscle, medial to the anterior superior iliac spine to reach the upper antero-lateral region of the thigh

Question 6

Knee extension is innervated by which nerve and nerve root?

Answer 6

Femoral nerve (L2-L4)

Question 7

Hip adduction is innervated by which nerve ?

Answer 7

Obturator nerve (L2-L4)

Question 8

Illioinguinal Nerve (L1)

Answer 8

• supply the skin and muscles of the lower abdominal wall

more specifically it supply the transverse abdominis and the internal oblique muscles

• anterior divisions only
• skin over the pubic bone
• skin around the upper medial part of the femoral triangle & part of the external genitalia (scrotum, labia)

Question 9

Ilio-hypo-gastric nerve (L1)

Answer 9

• supply transverse abdomens and the internal oblique muscles
• outer strip of the lateral buttock, pubis
• sends out anterior and lateral branches
• transverse over the iliac crest

Question 10

Saphenous nerve (L3-L4)

Answer 10

• terminal branch from the femoral nerve, right below to the knee joint (infra-patella branch)
• wraps around the knee, traveling with the saphenous vein to supply the medial leg

Question 11

The location of the sacral plexus

Answer 11

The sacral plexus is formed on the anterior surface of the piriformis muscle, postern-lateral border of the pelvic wall.

Question 12

The sacral plexus descends down the posterior wall of the pelvis and have 3 possible courses.

Answer 12

1) leave via the greater sciatic foramen and enter the gluteal region either below or above the piriformis muscle
2) remains within the pelvis innervate the pelvis muscle, organs and perineum
3) exit the greater sciatic foramen just to loop around the sacraspinous ligament and re-enter via the lesser sciatic foramen, supplying the lateral pelvic structures and perineum structures.

Question 13

What is the sacral plexus?

Answer 13

is a network of nerve fibers that supplies the skin and muscle of the pelvis and lower limb.

It is formed by the anterior rami of nerve roots L4–S4 and divided into 5 major peripheral nerves.

Question 14

What is the limbo-sacral trunk

Answer 14

It is formed through nerve root L4 & L5 which joins with the sacral plexus in the pelvis.

Question 15

Which nerve and nerve root innervates the Tensor Fascia Lataa

Answer 15

The superior gluteal nerve (L4-S1)

Question 16

The ventral division of the sciatic nerve and nerve roots?

Answer 16

Tibial nerve (L4, L5, S1, S3)

Question 17

The sciatic nerve give branches to which muscles?

Answer 17

• semimembranosus
• semitendonosis
• biceps femoris
• adductor Magnus hamstring part

Specifically, these muscles are innervated by the tibial component of the sciatic nerve.

Question 18

Which nerve innervates the posterior compartment of the leg?

Answer 18

Tibial nerve

Question 19

Which nerve innervates the muscles in the sole of the foot?

Answer 19

Tibial nerve

Question 20

Which nerve innervates the muscles on the anterior and lateral compartment of the leg?

Answer 20

Common peroneal nerve

Question 21

This nerve innervates the biceps femoris shorthead and the extensor digitorum brevis muscle

Answer 21

Common peroneal nerve

Question 22

Which nerve innervates the lateral leg muscles?

Answer 22

The superficial peroneal nerve of the common peroneal nerve

Question 23

Which nerve innervates the anterior leg muscles

Answer 23

The deep peroneal nerve

Question 24

Which nerve innervates the skin of the lateral ankle and dorsum of the foot?

Answer 24

The superficial peroneal nerve

Question 25

The course of the posterior cutaneous nerve of the thigh? and nerve roots and supply?

Answer 25

Like the other 4 major peripheral nerves from the sacral plexus,

• exits the greater sciatic foramen inferior to the piriformis muscle and run deep to the gluteus Maximus and run down the back of the thigh to the knee
• innervates the skin at the back of the thigh and the leg and the skin of the perineum
• S1-S3

Question 26

The obturator nerve and the pedestal nerve are the only two nerves that do what?

Answer 26

• Exit the greater sciatic foramen, loop around the sacraspinous ligament, re-entered the pelvic cavity via the lesser sciatic foramen

Question 27

The pudental nerve supply

Answer 27

muscles of the perineum, external urethral sphincter, anal and the LEVATOR ANI muscles.

the penis and the clitoris and most of the skin of the perineum

Question 28

Inferior Gluteal nerve supply

Answer 28

dorsal division of the anterior rami of L5-S1
supply the gluteus Maximus muscle
no cutaneous supply

Question 29

Nerve to piriformis muscle

Answer 29

S2, and sometimes S1

innervates the piriformis directly

Question 30

Nerve to obturator internus

Answer 30

L5-S2

also supply the gemellus muscle, superior

Question 31

Nerve to quadrates femoris

Answer 31

L4-S1 also innervates the inferior gemellus muscle