Lab 2

Question 1

What is the thalamus, and where is its location in the brain?

Answer 1

It’s responsible for relaying sensory and motor information to the primary cortices.
It’s shaped like a dumbell, with a lobe on either side of the third ventricle, connected by a thin ‘bar’

Question 2

What is the function of the mamillary body?

Answer 2

smell

Question 3

What produces CSF?

Answer 3

Chorioid plexuses

Question 4

Where does the third ventricle extend relative to the thalamus?

Answer 4

Anterior and posterior to it.

Question 5

Where is peripheral vs. central vision in the primary visual cortex?

Answer 5

Peripheral is more anterior, central is peripheral (thus it’s more easily damaged by a knock)

Question 6

Where does the midbrain begin and end?

Answer 6

Upper boundary: Runs from the occular motor nerve to the top of the superior colliculus
Lower boundary: From top of pons to bottom of inferior colliculus

Question 7

What is the cerebral aqueduct?

Answer 7

Transports CSF from third to fourth ventricle

Question 8

What are the cerebral peduncles?

Answer 8

Located above the pons in the midbrain, responsible for refining movement

Question 9

What are the colliculi?

Answer 9

Superior colliculus: Reflexes to sight

Inferior colliculus: Reflexes to sound

Question 10

What structure contains both white and gray matter?

Answer 10

Pons

Question 11

What does the 4th ventral look like in cross section?

Answer 11

A little triangle

Question 12

What is interesting about the cerebellum?

Answer 12

It doesn’t decussate (ipsilateral). Ie. the right cerebellum controls the right side of the body.

Question 13

What are the features of the brain in lateral view which can help us identify the lobes?

Answer 13

The central sulcus
The lateral fissure
The parieto-occipital sulcus runs from the notch at the superior surface of the brain, which runs down to the pre-occipital notch (where the angle of the brain’s base changes).
By extending the central sulcus to meet the lateral fissure, and the lateral fissure to meet the parieto-occipital sulcus, the lobes of the brain can be identified.

Question 14

What is interesting about where primary vs secondary association areas are located in the brain?

Answer 14

Primary areas are located in both hemispheres, whereas secondary areas are only located in the dominant hemisphere

Question 15

Where is the striatum relative to the thalamus?

Answer 15

Lateral and anterior to the thalamus

Question 16

What is the form of the caudate nucleus?

Answer 16

It is lateral to the lateral ventricles, and is C shaped, with a bulbous anterior head and a thin tail

Question 17

How do you tell the putamen from the caudate nucleus in an anterior coronal slice (when they are connected)?

Answer 17

The caudate nucleus is more solid looking than the putamen

Question 18

What does the corpus callosum look like in a coronal slice?

Answer 18

A white bridge just inferior to the longitudinal fissure

Question 19

What do the lateral ventricles look like in a coronal slice?

Answer 19

Holes just below the corpus callosum

Question 20

What do the internal capsules look like in coronal slices?

Answer 20

They are only visible when the middle of the brain is sliced- they come between the putamen and the thalami, and are two vertical ish white matter lines

Question 21

How can you find the caudate nuclei on a coronal slice?

Answer 21

They are always just touching the superior lateral ventricles.

Question 22

What does the third ventricle look like in coronal slice?

Answer 22

It is a small, oval hole between two gray matter bulbs (the thalamus)

Question 23

How can you identify the substantia nigra?

Answer 23

it is always very, very dark.

Question 24

What does the fourth ventricle look like in coronal slice?

Answer 24

It’s in the white matter of the cerebellum, a small hole.

Question 25

What are association fibres?

Answer 25

They run anterior to posterior

Stay in a single hemisphere (eg. arcuate fasciculus)

Question 26

What are commissural fibres?

Answer 26

They link hemisheres together
Run lateral to medial
Eg. corpus callosum

Question 27

What are projection fibres?

Answer 27

Run inferior to superior

Eg. corticospinal fibres

Question 28

What are the general steps of receiving input and performing an output in the brain?

Answer 28

1. Receive input
2. Understand
3. Plan response
4. Conduct response
5. Feedback

Question 29

What are the steps of hearing a question and speaking a reply?

Answer 29

1. Receive input (Primary auditory cortex separates sound tonotopically)
2. Understand (Wernicke’s area receives sounds, understands them)
3. Plan response (brocas area)
4. Conduct response (Motor cortes)
5. Feedback (Auditory cortex, ensuring what you’ve said is right

Question 30

What are the steps of reading a question and writing a reply?

Answer 30

1. Receive input (Visual cortex) –> Supplementary visual cortices for interpretation of what you’re seeing
2. Understand (SMAGLA / AGLA)
3. Plan response (association fibre to exener’s area)
4. Conduct reponse (Motor cortex)
5. Feedback (Visual cortices)