Overview of the Nervous System

Question 1

What does the CNS consist of?

Answer 1

Brain and spinal cord

Question 2

What are the 3 functional divisions of the CNS?

Answer 2

Central Nervous System (CNS)
Somatic Nervous System (SNS)
Autonomic Nervous System (ANS)

Question 3

What does the Somatic nervous system (SNS) consist of?

Answer 3

Cranial nerves and Spinal nerves. To and from the sensory organs and the muscles, joints and skin.

Question 4

What does the SNS do?

Answer 4

Produces movement and transmits incoming sensory information to the CNS, including vision, hearing, pain, temperature and the position & movement of body parts

Question 5

What does the Autonomic nervous system (ANS) consist of?

Answer 5

Sympathetic division and Parasympathetic division

Question 6

What does the ANS do?

Answer 6

Balances the bodys internal organs to ‘rest and digest’ through the parasympathetic nerves OR ro ‘fight and flee’ or engage in vigorous activity through the sympathetic nerves.

Question 7

Within the bony case enclosing the CNS is a triple-layered set of membranes

Answer 7

The meninges

Question 8

What is the outer layer of the meninges called?

Answer 8

The dura mater (tough double layer of tissue enclosing the brain in a loose sack).

Question 9

What is the middle layer of the meninges called?

Answer 9

The arachnoid membrane (thin sheet of delicate tissue that follows the contours of he brain)

Question 10

What is the inner layer of the meninges called?

Answer 10

The pia mater (moderately tough tissue that clings to the surface of the brain)

Question 11

What cushions the brain and spinal cord from shock?

Answer 11

The cerebrospinal fluid (CSF)

Question 12

What is the function of the meninges and CSF?

Answer 12

The triple-layers encase the brain and spinal cord while the CSF cusions them

Question 13

What protects the brain and spinal cord from many chemical substances?

Answer 13

The blood-brain barrier

Question 14

How does the blood-brain barrier work?

Answer 14

To form the barrier, the cells of the capillaries form tight junctions with one another to prevent blood-borne substances from crossing from the capillaries into the CNS tissues.

Question 15

Why is the PNS more vulnerable to injury that the CNS?

Answer 15

Because it lacks bony protection like the CNS which has the skull and interlocking bony vertebre to protect the brain and spinal cord.

Question 16

Can the PNS repair itself better than the CNS?

Answer 16

Yes, even though it lacks bony protection it has the ability to renew itself after injury by growing NEW axons and dendrites.

Question 17

Where does the brain recieve its blood from?

Answer 17

4 arteries– 2 internal carotid arteries and 2 vertebral arteries that course up each side of the neck

Question 18

What are the names of the 3 major cerebral arteries?

Answer 18

1) Anterior cerebral artery (ACA)
2) Middle cerebral artery (MCA)
3) Posterior cerebral artery (PCA)

Question 19

What part of the brain does the ACA irrigate?

Answer 19

The medial and dorsal part of the cortex

Question 20

What part of the brain does the MCA irrigate?

Answer 20

The lateral surface of the cortex

Question 21

What part of the brain does the PCA irrigate?

Answer 21

The ventral and posterior surfaces of the cortex