Lecture 12. PNS

Question 1

What nerve is present in the

a. spinal nerve
b. ventral ramus
c. dorsal ramus

Answer 1

all contain mixed nerves

Question 2

Which is thicker the ventral or dorsal ramus?

Answer 2

central rami

Question 3

What do the ventral ramus form

Answer 3

form the somatic nerve plexus 
somatic nerve plexus consists of : 
-cervical plexus
-lumbar plexus 
- sacral plexus

Question 4

What is the ventral rami of the thoracic spinal nerve (T1-T11) called?

Answer 4

intercostal nerve

Question 5

What is the ventral rami of the thoracic spinal nerve ( T12) called

Answer 5

subcostal nerve

Question 6

What does the dorsal rami supply?

Answer 6

supplies the paravertebral musculature and the overlying skin at the posterior end

Question 7

What is the cauda equina

Answer 7

A bundle of spinal nerves

Question 8

What is a dermatome?

Answer 8

area of skin innervated by a single spinal nerve or spinal cord segment

Question 9

What is a myotome

Answer 9

Part of the skeletal muscle innervated by a single spinal nerve or spinal cord segment

Question 10

What is a nerve plexus?

Answer 10

An intertwined network of nerve fibers

Question 11

Describe what is in the somatic plexus

Answer 11

1. carries fibers from several spinal nerves

2. fibers from each ventral ramus distributes via several different branches

Question 12

What are the branches of the cervical plexus

Answer 12

1. cutaneous branch
2. motor branch
   - phrenic
   - ansa cervicalis

Question 13

What does the phrenic subdivision of the cervical plexus innervate

Answer 13

It innervates the diaphragm, by C3, C4,C5

Question 14

What does the ansa cervicalis subdivision of the cervical plexus innervate?

Answer 14

Innervates most of the infrahyoid muscles

Question 15

What are the spinal nerves that are part of the brachial plexus

Answer 15

ventral rami of the spinal nerves C5-T1, they form the roots of the plexus

Question 16

How many trunks are there in the brachial plexus and which spinal nerves form which trunks

Answer 16

There are 3 trunks of the brachial plexus ( superior, middle and inferior).
Superior is made up of C5- C6
Middle (C7)
Inferior C8-T1

Question 17

How do the trunks of the brachial plexus divide into, what do they form

Answer 17

Anterior and posterior division of the trunks of the brachial plexus form cords

Question 18

How many cords are there in the brachial plexus? What constitutes the cords?

Answer 18

There are 3 cords: medial, lateral and posterior cords

Question 19

Where do the spinal nerves leave the spinal cord

Answer 19

intervertebral foreman

Question 20

Where do spinal nerves leave the sacrum

Answer 20

sacral foreman

Question 21

Where is the origin of the musculocutanrous nerve. where is it distributed

Answer 21

lateral cord. they are distributed to the muscles of the anterior compartment of the arm ( anterior and posterior lateral- radius portion).

Question 22

Where is the origin of the ulnar nerve?where is it distributed

Answer 22

medial cord. It travels on the medial side of the arm, passes behind the medial epicondyle and front of the carpal. 1 1/2 muscles in the anterior formearm, skin of the medial 1/3 of the palmar and dorsal aspect of the hand

Question 23

Where is the origin of the median nerve, where is it distributed

Answer 23

Medial and lateral cords. they innervate all muscles of the anterior component of the forearm

Question 24

where does the radial nerve originate from and where is it distributed

Answer 24

posterior cord. It supplies the muscles of the posterior compartments of the arms and forearm.skin of the posterior aspect of the arm and forearm

Question 25

What are the spinal nerves that form the lumbar plexus?

Answer 25

Formed by the ventral rami of the spinal nerves of L1-L4.

Question 26

What is the function of the lumbar plexus

Answer 26

Have branches of the plexus that innervate muscles and skin of the lower limb

Question 27

What spinal nerves form the lateral femoral cutaneous

Answer 27

L2-L3 spinal nerves. It distributes the skin of the lateral aspect of the thigh

Question 28

What spinal nerves form the obturator . what is its distribution

Answer 28

L2,L3,L4. It innervates muscles of medial compartments of thight and skin of the medial side of the thigh

Question 29

What spinal nerves forms the femoral nerve, what is its distribution

Answer 29

L2,L3,L4. It innervates the muscles of the anterior compartment of the thigh, and skin of the anterior and medial aspects of the thigh

Question 30

What spinal nerves form the sacral plexus

Answer 30

L4-S4 ventral ramus of the spinal nerve

Question 31

What is innervated by the superior gluteal

Answer 31

gluteus medius, minimus muscles

Question 32

What is innervated by the inferior gluteal

Answer 32

gluteus maximus muscle

Question 33

What forms the sciatic nerve

Answer 33

1. tibular nerve
2. common fibular nerve
   a. deep fibular nerve
   b. superficial fibular nerve

Question 34

What nerves in the cervical plexus that innervates the diaphragm

Answer 34

C3-C5

Question 35

What is the thickest nerve of the body

Answer 35

sciatic nerve

Question 36

What is innervated by the tibial nerve

Answer 36

hamstring muscles of the posterior compartment of the leg. muscles of the sole of the foot supplied

Question 37

What is innervated by the the fibular nerve

Answer 37

muscles of the anterior and lateral compartment of the leg

Question 38

What sacral spinal nerves form the pudendal nerve, what does it innerate

Answer 38

S2,S3,S4, muscles of the perineum and skin of the perineum