Nervous System and Homeostasis

What is the function of the nervous system?

It enables organisms to react to their surroundings and coordinates behaviour.

What are the two parts of the central nervous system?

Brain and spinal cord.

Why are reflex actions described as rapid and automatic?

They do not involve the conscious part of the brain.

Why are reflex actions important?

For survival and to prevent damage to the body.

What is the pathway of a nervous response?

Stimulus → receptor → coordinator → effector → response.

What is the function of the cerebral cortex?

It plays an important role in consciousness.

What is the function of the medulla oblongata?

It controls breathing and heart rate.

What is the function of the cerebellum?

It is involved in coordinating muscle activity.

Why is it difficult to treat brain disorders?

The brain is very complex and delicate.

What is a synapse?

A gap between two neurones, allowing impulses to cross.

What is the function of neurones?

To carry electrical impulses around the body.

What is homeostasis?

Maintenance of a constant internal environment.

Give three internal conditions controlled in homeostasis.

Body temperature, blood glucose concentration, and water levels.

What are three things all control systems include?

Receptors, coordination centres, and effectors.

What is accommodation?

The process of changing the shape of the lens to focus on near/distant objects.

Give two common defects of the eyes.

Myopia (short-sightedness) and hyperopia (long-sightedness).

How can eye defects be treated?

Spectacle lenses, contact lenses, laser surgery, and replacement lenses in the eye.

Where is body temperature monitored and controlled?

Thermoregulatory centre in the brain.

What happens if body temperature is too high?

Blood vessels dilate (vasodilation) and sweat is produced.

What happens if body temperature is too low?

Blood vessels constrict (vasoconstriction), sweating stops, and shivering takes place.