Parts Of The Brain

Question 1

What is the cerebrum divided into?

Answer 1

2 hemispheres

Question 2

What are the 2 hemispheres of the cerebrum connected by?

Answer 2

The corpus callosum

Question 3

What surface area does the outermost layer of the cerebrum have?

Answer 3

2.5m2

Question 4

What is the outermost layer of the cerebrum like, what does it consist of and what is this called?

Answer 4

• It is folded

* It consists of a layer of nerve cell bodies called the cerebral cortex.

Question 5

What is the cerebral cortex in control of?

Answer 5

• emotional response and conscious thought
• ability to override certain reflexes
• features associated with intelligence; judgement and reasoning

Question 6

What is the cerebrum?

Answer 6

The largest and most recognisable part of the brain.

It is responsible for elements of the nervous system associated with being ‘human’ - imagination, reasoning and thought.

Question 7

What’s the cerebral cortex subdivided into?

Answer 7

Areas responsible for specific activities and body regions

Question 8

What are these areas and what do they do?

Answer 8

• Sensory areas: receive impulses indirectly from the receptors
• Association areas: compare input with previous experiences to interpret what the input means and judge an appropriate response
• Motor areas: send impulses to effectors (muscles and glands)

Question 9

What alone cannot operate the human body in a coordinated way?

Answer 9

The conscious decision to move voluntary muscles, initiated by the cerebral cortex

Question 10

How many nerve cells in the brain does the cerebellum contain?

Answer 10

Over half of all nerve cells in the brain

Question 11

What are the names of the two areas of the brain associated with understanding language and speaking and where are they located?

Answer 11

Names:
• Wernicke’s area
• Broca’s area

Location:
• Left cerebral hemisphere

Question 12

What are …
• Broca’s area
• Wernicke’s area

Answer 12

Broca’s area:
•Named after Paul Broca
•In 1860s, he examined the brains of patients with an inability to speak (aphasia) and discovered the region responsible for this problem in the brain

Wernicke’s area:
•Named after Karl Wernicke
•In 1860s, he identified another region, damage to which caused problems with understanding language

Question 13

What are Wernicke’s area and Broca’s area connected by?

Answer 13

A bundle of neurones

Question 14

What happens if this bundle of neurones is damaged?

Answer 14

An individual will be able to understand language but UNABLE to repeat words

Question 15

Suggest whether …

1) Broca’s area
2) Wernicke’s area

… is a sensory/motor/association area

Answer 15

1) Broca’s area = motor area
• damage results in inability to make motor movements associated with speaking

2) Wernicke’s area = association area
• damage results NOT in the loss of sensory function but the ability to make sense of the sensory input received

Question 16

What’s different about the cerebral cortex in humans than in other organisms?

Answer 16

It is more developed in humans than in any other organism

Question 17

What is the hypothalamus?

Answer 17

The hypothalamus controls the autonomic nervous system and the endocrine glands

Question 18

What are some examples of nonconscious operation?

Answer 18

1. Muscular activities associated with responding to changes in body position
2. Sensory activities e.g. judging position of objects and limbs
3. Tensioning of muscles to manipulate tools/instruments effectively
4. Feeding back information on muscle position, tension + fine movements
5. Operation of antagonistic muscles to coordinate contraction + relaxation

Question 20

What do neurones from the cerebellum do and what does this explain?

Answer 20

Neurones from the cerebellum carry impulses to the motor areas so that the motor output to the effectors can be adjusted appropriately in relation to these requirements.

• this explains why we often go on “auto-pilot” when carrying out such activities, as they are said to become programmed into the cerebellum.

Question 21

What is the cerebellum?

Answer 21

The cerebellum controls the coordination of movement and posture

Question 22

Suggest what effect damage to the cerebellum may have on a person

Answer 22

Damage to the cerebellum results in:
• General lack of muscular coordination
• ability to walk properly is affected, as impulses from the balance organs in the inner ear are not effectively coordinated with muscular movements associated with balance

(People with such damage appeared to be intoxicated by alcohol in terms of how they move)

Question 23

What is the function of the hypothalamus?

Answer 23

1. Controls most of the body’s homeostatic mechanisms
2. Controls much of endocrine function of the body because it regulates the pituitary gland
3. Receives sensory input from temperature receptors and osmoreceptors:
   leads to initiation of automatic responses that regulate..
   • body temperature
   • blood water potential

Question 24

Where does the cerebellum process sensory information in order for it to carry out its function?

Answer 24

• the retina
• the balance organs in the inner ear
• the joints
• specialised fibres in muscles (spindle fibres) which give info on muscle tension

Question 26

What is the medulla oblongata?

Answer 26

The medulla oblongata controls the action of smooth muscle in the gut wall, and controls breathing movements + heart rate

Question 27

What is the function of the medulla oblongata?

Answer 27

1. Controls non-skeletal muscles (cardiac + involuntary muscles)
2. Effectively in control of the autonomic nervous system
3. It is home to a number of regulatory centres for a number of vital processes:
   • cardiac centre; regulates heart rate
   • Respiratory centre; controls breathing + regulates rate + depth of breathing

Question 31

What does the fine control of muscular movements -such as that involved in walking/riding bike/driving - require?

Answer 31

A significant degree of non-conscious operation

Question 34

List the areas of the brain that would be involved in:

1) reading out loud
2) singing along to a song on the radio

Answer 34

1) 
visual sensory area
visual association area
Wernicke's area
Broca's area
Hearing sensory area

2)
Hearing sensory area
Hearing association area 
Wernicke's area
Broca's area

Question 36

Explain why a cerebrovascular accident (stroke) leading to damage to the left side of the brain can result in paralysis of the right arm and leg.

Answer 36

This is because the motor centres at one side of the brain are responsible for stimulating movement in the muscles in the opposite side of the body