Introduction To The Nervous System

Question 1

What is a funiculus?

Answer 1

A segment of white matter containing multiple distinct tracts. Impulses travel in multiple directions

Question 2

What is a tract?

Answer 2

An anatomically and functionally defined white matter pathway connecting two distinct regions of grey matter. Impulses travel in one direction.

Question 3

What is a fasciculus?

Answer 3

A subdivision of a tract supplying a distinct region of the body.

Question 4

What is a nucleus?

Answer 4

A collection of functionally related cell bodies

Question 5

What are association fibres?

Answer 5

Fibres which connect regions within the same hemisphere

Question 6

What are commisural fibres?

Answer 6

Fibres which connect the left and right hemispheres or cord halves

Question 7

What are projection fibres?

Answer 7

Fibres which connect the cerebral hemispheres with the cord/brainstem

Question 8

What are the major functions of the midbrain?

Answer 8

Eye movements and reflex responses to sound and vision

Question 9

What are the major functions of the pons?

Answer 9

Feeding and sleep

Question 10

What are the major functions of the medulla?

Answer 10

Cardiovascular and respiratory centres

Contains a major motor pathway (medullary pyamids)

Question 11

How is CSF produced, distributed throughout the brain and spinal cord and reabsorbed?

Answer 11

Produced in choroid plexus which is found within each of the ventricles. CSF flows from lateral ventricles—> interventricular foramen—> 3rd ventricle—> cerebral aqueduct—> 4th ventricle—> spinal cord + sub arachnoid space—> reabsorbed through arachnoid granulations into dural venous sinuses.

Question 12

The right half of our vision is controlled by which occipital lobe?

Answer 12

The left occipital lobe

Question 13

The superior part of our vision is carried by which radiation?

Answer 13

The inferior radiation

Question 14

The inferior radiations travel through which lobe?

Answer 14

The temporal lobe

Question 15

A lesion in the left inferior radiation will produce which type of visual loss?

Answer 15

Right upper quadrantonopia

Question 16

A lesion in the right optic tract will produce what type of visual loss?

Answer 16

Left homonomous hemianopia

Question 17

A lesion in the optic chiasm will produce what type of visual loss?

Answer 17

Bitemporal hemianopia

Question 18

Why do you get macular sparing if the lesion is in the occipital lobe?

Answer 18

The part of the occipital lobe that supplies the macula is supplied by the middle cerebral artery whereas the rest of the occipital lobe is supplied by the posterior cerebral artery so in a PCA stroke there will be a contralateral hemianopia with macula sparing.

Question 19

What is the accomodation reflex?

Answer 19

It is required for near vision
 There are 3 Cs-
Convergence
Constriction of pupil
Convexity of lens

Cerebral cortex must be involved as it is relating to image analysis

Question 20

How does the accomodation reflex work?

Answer 20

Once the information from the eye has reached the visual cortex it travels to the midbrain where it synapses with the oculomotor nerve. The oculomotor nerve causes the medial rectus muscle to contract causing covergence and it also causes relaxation of ciliary muscle and contraction of contrictor pupillae.