Nervous System 2.2 Module 3

Question 1

LABEL PLEXUS!

Answer 1

–

Question 2

What do the spinal nerves connect to?

Answer 2

The spinal nerves connect to the spinal cord via roots

Question 3

Dorsal root?

Answer 3

Sensory

Question 4

Ventral root?

Answer 4

Motor

Question 5

FACT list

Answer 5

8 central nerves
12 thoracic nerves
5 lumbar nerves
5 sacral nerves
1 coccygeal nerve

Question 6

What is a mixed structure?

Answer 6

The mixed refers to a structure having both sensory and motor fibers (the dorsal and ventral roots merge)

Question 7

what do spinal nerves branch from?

Answer 7

The spinal nerves branch to form dorsal and ventral rami

Question 8

What is the dorsal rami?

Answer 8

The dorsal rami provide sensory and motor innervations (to supply with nerves) to the skin and smaller back muscles

Question 9

What is the ventral rami?

Answer 9

The ventral rami provide sensory and motor innervations to the rest of the trunk and larger limbs (FIG)

Question 10

What is the nerve plexuses formed by?

Answer 10

The nerve plexuses are formed by the ventral rami, the plexuses contain fiber of different spinal nerves, the fibers from each rami project many pathways

Question 11

What are the overlapping territories?

Answer 11

The overlapping territories means that each muscle receives input from more than 1 spinal nerve (important when spinal nerves are damaged)

Question 12

what are the four main plexuses?

Answer 12

Cervical, branchial, lumbar and sacral

Question 13

What is the order?

Answer 13

5 roots (rami), 3 trunks (inf, middle, sup), 3 cords (lateral, posterior and medial) and 5 peripheral nerves

Question 14

What is the cervical plexus?

Answer 14

located under the sternocleidomastoid, innervates the skin

Question 15

What is the brachial plexus?

Answer 15

the branchial plexus is located in the neck and innervates the upper limb

Question 16

What is the lumbar plexus?

Answer 16

Lumbar plexus was located within POSOAS muscle innervates abdominal wall, anterior and medial thigh

Question 17

What is the sacral plexus?

Answer 17

The sacral plexus is located posterior to lumbar plexus, innervates butt, lower limb and pelvis

Question 18

What are the 5 important branches?

Answer 18

Axillary, musculocutaneous, median, Ulnar and Radial

Question 19

What are common brachial plexus injuries?

Answer 19

Injuries to the brachial plexus are common can weaken or paralyse the arm. Like capal tunnel syndrome: the median nerve is compressed (wrist)
Ulnar nerve are vulnerable “funny bone” is superficial
Brachial plexus birth palsy ( difficult delivery leads to the paralysis of the the baby)

Question 20

What are the different cranial nerves?

Answer 20

12 pairs (sensory, motor and mixed) are arranged along the longitudinal axis of the brain

Question 21

Steps of cranial nerves?

Answer 21

1) cranial nerve attached to the cerebrum, 2) Cranial attaches to the diencephalon and 3) C.N iii -xiii attaches to brain stem