Nervous System Pt 1

Question 1

Nerves associated with the brain stem are known as

Answer 1

Cranial nerves

Question 2

What is a multipolar neuron? Pseudounipolar? Bipolar? Where are they found?

Answer 2

Mutlipolar neuron has MANY dendrites and a single axon, pseudounipolar looks like it has one dendrite, bipolar has 2 dendrites.
Multipolar- motor (anterior- ventral)
Psuedounipolar- sensory (posterior- dorsal)
Bipolar- hearing

Question 3

The nervous system is split into 2 parts:

Answer 3

Central (CNS- Within skull and vertebral column) and Peripheral (PNS- Outside of the CNS)

Question 4

What does the cerebral hemisphere consist of?

Answer 4

the cerebrum - use to think

diencephalon (thalamus, hypothalamus, epithalamus, subthalamus)

Question 5

What does the brain stem consist of? What does it turn into?

Answer 5

The midbrain, pons and medulla –> turns into the spinal cord

Question 6

What is located posterior to the brain stem?

Answer 6

The cerebellum

Question 7

The peripheral nervous system consists of 2 types of nerves:

Answer 7

Spinal nerves and cranial nerves- by definition these are outside of the CNS

Question 8

How many cervical nerves are there? Thoracic? Lumbar? Sacral? Coccygeal?

Answer 8

8 cervical nerves but only vertebrae! How? First comes out above C1. 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal nerve.

Question 9

What are cranial nerves 1 and 2 associated with?

Answer 9

The cerebral hemisphere`

Question 10

What are cranial nerves 3-10 and 12 associated with?

Answer 10

The brain stem

Question 11

What is cranial nerve 11 associated with?

Answer 11

The upper spinal cord (accessory nerve)

Question 12

What are spinal nerves associated with?

Answer 12

The spinal cord

Question 13

What is a ganglia? What are the two types?

Answer 13

A collection of nerve cell bodies associated with PERIPHERAL nerves and located OUTSIDE the CNS. Sensory (spinal nerve and cranial nerve ganglia) and motor (sympathetic ganglia and parasympathetic ganglia).

Question 14

Describe the pathway of a sensory ganglia?

Answer 14

Stimulus comes in (hand on iron) through a mixed spinal nerve to the ganglia (OUTSIDE the CNS) this 1st order nerve sends a message through the dorsal horn and to CNS. Takes signal and makes motor function out of anterior horn down a multipolar neuron.

Question 15

What does autonomic mean? What organs does it supply?

Answer 15

“Automatic” or visceral because they supply the viscera aka the heart, lungs, GI tract, urinary bladder etc. everything inside

Question 16

Where is an autonomic nerve cell body found? What kind of nerves?

Answer 16

Autonomic nerve cell bodies are located in motor or visceral ganglia found OUTSIDE the CNS (along the vertebral body in the diagrams). There are multipolar nerves.

Question 17

How many neurons pass from the CNS to the organ of innervation?

Answer 17

2, a pre-ganglionic and post-ganglionic neuron

Question 18

Describe the cervical spinal cord

Answer 18

Oval shape, due to large ventral horns which provide motor function to the upper limbs- lots of gray and white matter.

Question 19

Describe the thoracic spinal cord

Answer 19

Very circular in shape, small ventral horn because not a lot of motor function. Progressively less white matter.

Question 20

Describe the lumbar spinal cord

Answer 20

Circular in shape with lots of gray matter due to large ventral horns which supply motor functions to the legs. Progressively less white matter.

Question 21

Where are the lateral horns present? What is their function?

Answer 21

The lateral horns are present in the thoracic and lumbar vertebrae (to L2) these are the PREganglionic cell bodies or the sympathetic nervous system!

Question 22

What are the stripes in the white matter called? What is their functions?

Answer 22

These are called dorsal/lateral/ventral columns or funiculus. They are myelinated nerve fibers that run through the cord.

Question 23

What does the gray matter consist of? What type of nerve are they?

Answer 23

Nerve cell bodies and their processes- all gray matter is MULTIPOLAR

Question 24

Where are first order sensory neurons? Where are secondary order?

Answer 24

First order are the dorsal root ganglion, second order are in the dorsal horn

Question 25

What kind of neurons are in the ventral horns? What kind of neurons?

Answer 25

Motor- multipolar

Question 26

What is the difference between somatic and visceral nerves?

Answer 26

Somatic go out to the body (think skeletal muscle), visceral go to the interior organs of the body.

Question 27

Where do visceral and somatic nerve have their SENSORY cell bodies?

Answer 27

ALL VISCERAL AND SOMATIC NERVES HAVE THEIR SENSORY CELL BODIES IN THE DORSAL ROOT GANGLIA

Question 28

Where do visceral motor ganglia have their cell bodies?

Answer 28

In the lateral horn- autonomic

Question 29

Where do somatic motor ganglia have their cell bodies?

Answer 29

In the ventral horn

Question 30

How many efferent neurons are involved in the visceral motor (autonomic) nervous system?

Answer 30

TWO- first is always located in the CNS, second is located in an autonomic (visceral or motor) ganglion

Question 31

What are the subdivisions of the visceral/autonomic nervous system?

Answer 31

Sympathetic
Parasympathetic
Enteric (related to GI)

Question 32

What are the spinal nerves made of? Their precursors?

Answer 32

The anterior (motor) and posterior (sensory) rootlets come together to form the spinal nerve.

Question 33

What happens to the spinal nerve? What are its subdivisions? What muscles do they supply?

Answer 33

The dorsal and ventral root- dorsal goes to skin and deep muscles of the back and ventral goes everywhere else.

Question 34

Are spinal nerves motor or sensory? Do they have rami?

Answer 34

Both, yes.

Question 35

Are cranial nerves motor or sensory? Do they have rami?

Answer 35

Can be purely either or mixed! They DO NOT have dorsal/ventral roots.

Question 36

Are there sympathetic ganglia associated with cranial nerves? spinal nerves?

Answer 36

NONE with cranial nerves, they are ONLY parasympathetic and sensory– but ALL spinal nerves have sympathetic.