Hss Aqa Biology Unit 5 Homeostasis And Response 1

Front 1

Define homeostasis

Back 1

The regulation of the internal conditions of a cell or organism to maintain optimal conditions for function in response to internal and external changes.

Front 2

What are the 2 things that homeostasis maintain optimal conditions for?

Back 2

1. Enzyme action

2. All cell functions

Front 3

In the human body what are the 3 things that homeostasis controls?

Back 3

1. Blood glucose concentration

2. Body temperature

3. Water levels

Front 4

What are the 2 different types of automatic controls systems in the human body?

Back 4

1. Nervous (electrical) responses

2. Chemical (hormonal) responses

Front 5

What are the 3 things that all control systems include?

Back 5

1. Receptor cells

2. Coordination centres

3. Effectors

Front 6

What is the function of a receptor cell?

Back 6

To detect stimuli (changes in the environment).

Front 7

What are the coordination centres of the central nervous system?

Back 7

Brain and spinal cord

Front 8

What is the coordination centre in the control of blood glucose?

Back 8

The pancreas

Front 9

What are the coordination centres of the menstrual cycle?

Back 9

The pituitary gland and the ovaries.

Front 10

What do coordination centres do?

Back 10

They receive and process information from receptor cells.

Front 11

What are the two types of effects and what do they each do?

Back 11

Muscles and glands.

Muscles contract or relax

Glands either release or stop releasing hormones.

These actions restore the optimum levels.

Front 12

What is the function of the nervous system?

Back 12

To enable humans to react to their surroundings and coordinate their behaviour.

Front 13

S R C E R

Skinny Rabbits Can Eat Rats

Back 13

Stimulus

Receptor

Coordinator

Effector

Response

Front 14

Name the 3 neurones in a reflex arc and explain their function

Back 14

Sensory neurone - carries electrical impulse from receptor cell to coordinator.

Relay neurone - is in the brain or spinal and coordinates the response.

Motor neurone - carries electrical impulse from coordinator to effector, which brings about a response.

Front 15

What are the 3 main features of reflex responses and why are reflex responses important?

Back 15

Automatic

Rapid

Don’t involve the conscious parts of the brain

They are important because they protect us from danger.

Front 16

What is a synapse and how is information passed across one?

Back 16

A gap between 2 neurones. When an electrical impulse reaches the end of a neurone, chemicals are released from the neurone that diffuse across the synapse. The chemicals bind to the next neurone and trigger an electrical impulse in that neurone.

Front 17

Label

Back 17

Back (Definition)

Front 18

Describe what is happening at this synapse

Back 18

Back (Definition)

Front 19

Label the neurone

Back 19

Back (Definition)

Front 20

Describe what happens to trigger a response in a reflex reaction

Back 20

The receptor cell detects a change in the environment which triggers an electrical impulse to pass along the sensory, then relay, them motor neurones. At the end of the motor neurone is either a muscle which contracts or a gland which secretes a hormone to bring about the desired response.