Location and functions of various parts of the brain (3.1)

Question 1

What is the largest part of the brain?

Answer 1

The cerebrum is the largest part of the brain. It is divided into two cerebral hemispheres by a longitudinal fissure.

Question 2

What holds the cerebral hemispheres together?

Answer 2

The hemispheres are held together by a mass if myelinated nerve fibres, bundled into large tracts that form the corpus callosum.

Question 3

What is the importance of the corpus callosum?

Answer 3

It holds the hemispheres together, and this provides for communication between the cerebral hemisphere and lower parts of the CNS, enabling them to function as a co-ordinated whole.

Question 4

What is the surface of the cerebrum made up of?

Answer 4

It is made up of a large number of folds (gyro) and grooves (sulci).

Question 5

What do the folds and grooves on the surface of the cerebellum do? (2)

Answer 5

• They enlarge the surface area so that a large amount of brain cells can fit into a small cranial cavity.
• Deeper folds divide the cerebellum into four lobes

Question 6

There are four cavities known as ____ in the centre of the brain. They are filled with _____ fluid.

Answer 6

Ventricles

Cerebrospinal

Question 7

What forms the cerebral cortex?

Answer 7

The outer 3mm of the cerebrum. It is made up of a collection of cell bodies of neurons and forms what is called grey matter.

Question 8

Why is the grey matter grey?

Answer 8

The greyness is due to the grey appearance of the cytoplasm which is called neuroplasm in neurons.

Question 9

Why is below the grey matter?

Answer 9

An area of white matter made of a collection of myelinated nerve fibres.

Question 10

Why is white matter white?

Answer 10

Due to the fatty myelin.

Question 11

What 3 areas is the cerebral cortex divided into?

Answer 11

• The motor area
• The association cortex
• The sensory neurons

Question 12

What happens in the motor area?

Answer 12

It is in the frontal lobe where all the voluntary movements of the body originate. We are able to consciously control our voluntary movements that are brought about by contraction of the skeletal muscles.

Question 13

What happens in the sensory areas?

Answer 13

These are areas that receive and interpret impulses from the sense organs.

Question 14

Name what happens in each lobe:

• Frontal lobe:
• Parietal lobe:
• Temporal lobe:
• Occipital lobe:

Answer 14

• Frontal: Where all the voluntary movements of the body originate. We are able to consciously control our voluntary movements that are brought about by contraction of the skeletal muscles.
• Parietal: Skin sensations such as touch, cold and hot temperatures, pressure and pain.
• Temporal: Hearing, tasting and smelling
• Occipital: Sight

Question 15

What happens in the association cortex?

Answer 15

It is involved with higher mental activities such as intelligence, memory, perception, language and consciousness.

Question 16

What does an association area in the frontal lobe control?

Answer 16

Emotions eg. Anger and Aggression

Question 17

In each individual, ___ ___ hempishere is dominant. The dominant hemisphere controls………………. The non-dominant controls………………..

Answer 17

One cerebral
Language, mathematical and analytical functions and ‘handedness’.
Simple spatial concepts, being able to recognise faces, certain sounds and emotions.

Question 18

Where does the cerebellum lie?

Answer 18

It lies behind and below the cerebrum.

Question 19

How many hemispheres does the cerebellum?

Answer 19

It is made up of two hemispheres and has shallow surface folds.

Question 20

How is the arrangement of white and grey matter in the cerebellum unique?

Answer 20

The white matter looks like the branches of a tree and is surrounded by grey matter which looks like the foliage. hence the name ‘tree of life’.

Question 21

What is the function of the cerebellum? (3)

Answer 21

The cerebellum receives sensory input from the motor region of the cerebrum, the eyes, muscle spindles and organs of balance of in the ears.

1. It processes this info and uses it to co-ordinate the actions of voluntary muscles
2. It is partly responsible for muscle tone
3. Using info from the inner ear, it helps to maintain posture and balance.

Question 22

True or false

The cerebellum initates movement.

Answer 22

False, it co-ordinates movement. The motor area of the cerebrum initiates movement.