Origin & development of the CNS

Question 1

How many cerebral ventricles are there?

Answer 1

4! They are interconnected.

1) Right lateral ventricle
2) Left lateral ventricle
3) Third ventricle
4) Fourth ventricle

Question 2

What are the 1st and 2nd ventricles called?

Answer 2

The ‘lateral ventricles’. They form C shaped lakes underlying the cerebral cortex and there is one is each hemisphere.

Question 3

Where to the third and fourth ventricle lie?

Answer 3

In the midline of the brain

Question 4

What are ALL 4 ventricles filled with?

Answer 4

Cerebrospical fluid (CSF)

Question 5

What produces CSF?

Answer 5

The ependymal glial cells located adjacent to the ventricles

Question 6

Where does CSF flow?

Answer 6

From the lateral ventricles through the 4th ventricle and eventually into the circulatory system

Question 7

Where do the 3rd and 4th ventricles extend to?

Answer 7

They extend into the brainstem and spinal cord

Question 8

The spinal cord can also be regarded as the:

Answer 8

‘Tube of nerves’

Question 9

Afferent fibres (enter the spinal cord) and…

Answer 9

Bring information from sensory receptors to the body

Question 10

The spinal nerves that converge as they enter the spinal cord form a strand of fibres called the:

Answer 10

Dorsal root

Question 11

Efferent fibres (leave the spinal cord) and…

Answer 11

Carry information from the spinal cord to the muscles

Question 12

Fibres that leave the ventral part of the spinal cord

Answer 12

Ventral root

Question 13

Dorsally located tracts are:

Answer 13

SENSORY

Question 14

Ventrally located tracts are:

Answer 14

MOTOR

Question 15

What do spinal tracts do?

Answer 15

Carry information to and from the brain

Question 16

What colour is the OUTER part of the spinal cord?

Answer 16

White matter. White matter fibre tracts carry info to and from the brain

Question 17

What colour is the INNER part of the spinal cord?

Answer 17

Grey matter (compased largely of neural cell bodies)

Question 18

Fibres LEAVING the ventral root of the spinal cord:

Answer 18

Carry motor information to the muscles

Question 19

Fibres ENTERING the dorsal root of the spinal cord:

Answer 19

Bring sensory information from sensory receptors

Question 20

Collateral branches of sensory neurons may cross to the other side and influence motor neurons on that side. This might…

Answer 20

Extend to adjacent segments to influence adjacent body parts

Question 21

The Bell-Magendie law states that…

Answer 21

The dorsal part of the spinal cord is sensory and the central part is motor

Question 22

What does the SNS consist of?

Answer 22

The spinal and cranial nerves that produce movement and transmit incoming sensory information to CNS.

Question 23

Why is sensory information important?

Answer 23

It plays a central role in eliciting different kinds of movements organised by the spinal cord.

Question 24

Movements dependent only on spinal-cord function are called…

Answer 24

Reflexes

Question 25

What kinds of sensory receptors in the bdoy are there?

Answer 25

Pain, temperature, pressure and sensations from joint or muscle movement

Question 26

The size of the spinal nerve fibre coming from each receptor is distinctive..

Answer 26

Generally, pain and temperature are smaller and those for touch and muscle sense are larger.

Question 27

The stimulation or pain and temperature receptors in a limb usually produce

Answer 27

Flexion movements (which bring the limb inward)

Question 28

If the stimulus is MILD only the ___ part of the limb flexes in response to it

Answer 28

Distal

Question 29

The ___ reflex causes the limb to extend outward, away from the body and causes the touched part of the limb to remain in contact with the surface

Answer 29

Extension