PNS extended

Question 1

what two components make up the sciatic nerve?

Answer 1

common fibular and tibial nerves

Question 2

What type of nerve is Cutaneous Bb.? Where ramus does it come from? what plexus does it originate from? and what is the function?

Answer 2

Sensory

it targets the skin of the neck, back of the head, and external ear

Comes from Ventral Ramus

Cervical Plexus

Question 3

What nerve type is Ansa cervicalis? and what is the function?

Answer 3

Motor nerve
Provides motor functions to infrahyoid muscles

Question 3

What type of nerve is the Phrenic nerve? and what does it do?

Answer 3

Motor nerve
Targets the diaphragm and helps us breathe

Question 4

What type of nerve is Musculocutaneous? What is its motor target and what is its sensory target?

Answer 4

Mixed
Motor - anterior arm
Sensory - lateral arm

Question 5

what type of nerve is the median nerve? what is its motor target? what is its sensory target?

Answer 5

mixed

motor - anterior compartment of forearm muscles and muscles of hand

sensory - lateral 2/3 of hand

Question 6

what type of nerve is radial nerve? what is its sensory and motor target?

Answer 6

Mixed

Sensory - Skin on the back of the arm, forearm, and hand

Motor - Triceps, wrist, and finger extensors.

Question 7

What type of nerve is ulnar nerve? what is its motor and sensory function?

Answer 7

Mixed

Motor: 1 1/2 muscle in forearm, most intrinsic muscle of hand

Sensory: medial border/side of hand

Question 8

From which spinal nerves does the brachial plexus originate?

Answer 8

C5–T1

Question 9

What is the first structure formed in the brachial plexus after the ventral rami?

Answer 9

Roots (C5, C6, C7, C8, T1)

Question 10

After the roots, what is the next structure formed in the brachial plexus?

Answer 10

Trunks (Upper, Middle, Lower)

Question 11

What are the divisions of the brachial plexus?

Answer 11

Each trunk splits into anterior and posterior divisions

Question 12

After the divisions, what structure forms in the brachial plexus?

Answer 12

Cords (Lateral, Posterior, Medial)

Question 13

From the cords, what structure is formed next?

Answer 13

Branches (4major nerves)

Question 14

What are the 4 major branches of the brachial plexus?

Answer 14

• Musculocutaneous nerve
• Median nerve
• Radial nerve
• Ulnar nerve

Question 15

What does the musculocutaneous nerve innervate?

Answer 15

Motor: Muscles of the anterior arm (e.g., biceps brachii, brachialis)

Sensory: Skin of the lateral forearm

Question 16

Which cord gives rise to the musculocutaneous nerve?

Answer 16

Lateral cord

Question 17

Which cords give rise to the median nerve?

Answer 17

Lateral and medial cords

Question 18

What cord gives rise to the ulnar nerve?

Answer 18

Medial cord

Question 19

Which cord gives rise to the radial nerve?

Answer 19

Posterior cord

Question 20

Which nerve is most likely affected by a “Saturday night palsy” (compression of the arm in an awkward position)?

Answer 20

Radial nerve

Question 21

Injury to the ulnar nerve can cause difficulty in which movement?

Answer 21

Flexing the fingers and hand (e.g., “claw hand”)

Question 22

From which spinal nerves is the lumbar plexus formed?

Answer 22

Ventral rami of L1–L4 (sometimes L5)

Question 23

What is the major function of the lumbar plexus?

Answer 23

nnervating the lower limb, abdominal muscles, and pelvis

Question 24

What are the major branches of the lumbar plexus?

Answer 24

- Lateral femoral cutaneous nerve - Obturator nerve - femoral nerve

Question 24

What is the sensory distribution of the femoral nerve?

Answer 24

Anterior and medial thigh, medial leg

Question 25

What is the motor distribution of the femoral nerve?

Answer 25

Anterior compartment of the thigh

Question 26

What is the sensory and motor distribution of the obturator nerve?

Answer 26

Medial compartment of thigh

Question 27

What is the function of the lateral femoral cutaneous nerve?

Answer 27

Sensory for lateral thigh

Question 28

What spinal nerves form the sacral plexus?

Answer 28

L4–S4

Question 29

Which nerve from the sacral plexus is the largest nerve in the body?

Answer 29

Sciatic nerve