The Brain

Question 1

What are the four main parts of the brain?

Answer 1

Cerebrum
Cerebellum
Hypothalamus and pituitary complex
Medulla oblongata

Question 2

What does the cerebrum do?

Answer 2

The largest part of the brain and organises most of our higher thought processes, such as conscious thought and memory.

Question 3

What does the cerebellum do?

Answer 3

Coordinates movement and balance.

Question 4

What does the hypothalamus and pituitary complex do?

Answer 4

Organises the homeostatic responses and controls various physiological processes.

Question 5

What does the medulla oblongata do?

Answer 5

Coordinates many of the autonomic responses.

Question 6

What are included in the higher brain functions that are controlled by the cerebrum?

Answer 6

Conscious thought
Conscious actions (including the ability to override some reflexes)
Emotional responses
Intelligence, reasoning, judgement and decision making
Factual memory

Question 7

What are the major tracts of neurones called that connect the two areas of the cerebrum called?

Answer 7

The corpus callosum.

Question 8

What is the outermost layer of nerves on the cerebrum called?

Answer 8

The cerebral cortex

Question 9

What is the cerebral cortex divided into?

Answer 9

Sensory areas
Association areas
Motor areas

Question 10

What does the sensory area in the cerebral cortex control?

Answer 10

They receive action potentials indirectly from the sensory receptors. The sizes of the regions allocated to receive input from different receptors are related to the sensitivity of the area that inputs are received from.

Question 11

What do the association areas in the cerebral cortex do?

Answer 11

Compare sensory inputs with previous experience, interpret what the input means, and judge an appropriate response.

Question 12

What do the motor areas of the cerebral cortex do?

Answer 12

Send action potentials to various effectors (muscles and glands). The sizes of the regions allocated to deal with different effectors are related to the complexity of the movements needed in the parts of the body. Motor areas on the left side of the brain control the effectors on the right side of the body and vice versa.

Question 13

What is the cerebellum involved in?

Answer 13

Balance and fine coordination of movement. The conscious decision to contract voluntary muscles is initiated in the cerebral cortex.

Question 14

What are the sensory receptors that supply the cerebellum with information?

Answer 14

Retina
Balance organs in the inner ear
Spindle fibres in the muscles - give information about muscle length and the joints.

Question 15

Give examples of fine motor movements that are controlled by the cerebellum.

Answer 15

Maintaining body position and balance
Judging the position of objects and limbs while moving about or playing sport
Tensioning muscles in order to use tools and play musical instruments effectively
Coordinating contraction and relaxation of antagonistic skeletal muscles when walking and running.

Question 16

How are the complex nerve pathways strengthened?

Answer 16

Through practice

Question 17

What are the cerebrum and cerebellum connected to?

Answer 17

They are connected to the pons.

Question 18

What is the pituitary gland?

Answer 18

An endocrine gland at the base of the brain, below but attached to the hypothalamus; the anterior lobe secretes many hormones; the posterior lobe stores and releases hormones made in the hypothalamus.

Question 19

How does the hypothalamus work to maintain a constant environment?

Answer 19

It acts by negative feedback.

Question 20

How does the hypothalamus regulate temperature?

Answer 20

The hypothalamus detects changes in core body temperature. Also receives sensory input from temp receptors in skin. Initiates responses to temp change that regulate body temp within a narrow range.

Question 21

How are changes in temperature mediated?

Answer 21

By the nervous system or by the hormonal system.

Question 22

How does the hypothalamus perform osmoregulation?

Answer 22

Contains osmoreceptors that monitor the water potential in the blood. When the water potential changes, the osmoregulatory centre initiates responses that bring about a reversal of this change.

Question 23

How are the responses to osmoregulation mediated?

Answer 23

By hormonal system via the pituitary gland.

Question 24

The pituitary system consists of two lobes. What are they?

Answer 24

The posterior lobe and the anterior lobe.

Question 25

What does the posterior lobe of the pituitary gland do?

Answer 25

Hormones such as ADH, which are manufactured in the hypothalamus, pass down the neurosecretory cells and are released into the blood from the pituitary gland.

Question 26

What does the anterior lobe do?

Answer 26

It produces its own hormones, which are released into the blood in response to releasing factors produced by the hypothalamus. These releasing factors are hormones that need to be transported only a short distance from the hypothalamus to the pituitary.

Question 27

What do the hormones released form the anterior lobe in the pituitary gland do?

Answer 27

Control a number of physiological processes in the body, including response to stress, growth reproduction and lactation.

Question 28

How does the medulla oblongata control non-skeletal muscle?

Answer 28

It sends action potentials out through the ANS.

Question 29

The medulla oblongata contains centres for regulating several vital processes. What are they?

Answer 29

The cardiac control centre, which regulates heart rate.
The vasomotor control centre, which regulates circulation and blood pressure.
The respiratory control centre, which controls the depth and rate of breathing.