Module 12 Central Nervous System

Question 1

Where is the cell body located in the afferent neuron?

Answer 1

In the peripheral

Question 2

Where is the cell body located in the efferent neuron?

Answer 2

In the CNS

Question 3

What does a cross-section of the spinal cord look like?

Answer 3

White matter is on the outer layer. It’s composed of axons.
Gray matter is on the inner layer composed of cell bodies and dendrites

Question 4

Sensory neurons enter via the ventral side of the body?

Answer 4

False, they enter the dorsal or back side of the body. Motor neurons exit via the ventral side of the spinal cord.

Question 5

Collection of cell bodies in the CNS (efferent neurons)

Answer 5

Nucleus

Question 6

Collection of cell bodies in the peripheral (afferent neurons)

Answer 6

Dorsal root ganglion

Question 7

There are a number of diseases that cause demyelination of axons. What defect would you expect in someone with demyelinated ventral root neurons?

A) Leaky blood brain barrier

B) Impaired vision

C) Inability to sense pain

D) Impaired/slow limb movement

Answer 7

Demyelination of the ventral root neurons means that efferent neurons are affected which would result in impaired/slow limb movement.

Question 8

What are the meninges?

Answer 8

These are three layers of protective tissue between the bones of the bran/spinal cord.

Question 9

DAP

Answer 9

Dura Matter
Arachnoid Matter
Pia Matter

Question 10

What does the brain float in?

Answer 10

Cerebral spinal fluid (also surrounds the spinal cord)
It’s also in between every single layer of the meninges and is located in the brain ventricles.

Question 11

What else can CSF do?

Answer 11

CSF also acts as a reservoir for the brain’s interstitial fluid (the fluid surrounding neural cells).
It ensures that the fluid around neurons has:
The correct ionic concentrations (essential for neural function).
Nutrients (such as glucose and ions) to support the brain’s metabolic needs.

Question 12

Which of the following substances do you think could get through the blood brain barrier? (There is more than one correct answer)

A) Glucose

B) Oxygen

C) Red blood cells

D) Glycogen

E) Cortisol

Answer 12

Glucose, oxygen, cortisol

Question 13

Sensory neurons are ____________ neurons and their cell bodies are in the _____________.

Answer 13

Afferent neurons
Dorsal root ganglion

Question 14

What is part of the peripheral nervous system

Answer 14

sensory nervous system

Question 15

Somatosensory neurons

Answer 15

Mechanoreceptors: Mechanoreceptors are triggered when the membrane of them deform and Na+ enters (touch)
Nociceptors: Pain
Thermoreceptors: The TRP (temperature sensitive receptors) are ion channels that are activated by exposure to hot and cold or (capsaicin, menthol, or eucalyptus oil)
Proprioceptors: Body Position

Question 16

Sensory information from the right side is interpreted in the left side of the brain otherwise known as contralateral primary somatosensory cortex

Answer 16

True

Question 17

The brain integrates all this information to provide a perception of a sensory stimulus. Usually multiple modalities are integrated to give a more complete picture of the stimulus (for example a meal will be perceived via touch, taste, smell and vision).

Answer 17

The finer discrimination you can do in a body part, the higher density of sensory receptors in that area. That also correlates with a greater area in the somatosensory cortex.