Lesson 5 : Homeostasis snd response

What is homeostasis?

the maintenance of a stable internal environment in the body

Name the 3 internal conditions that need to be controlled through homeostasis

1. Blood glucose concentration

2. Body temperature

3. Water levels

What are the 3 components of automatic control systems?

1. Receptors - cells that detect stimuli

2. Coordination centres - process information received from receptors

3. Effectors - bring about responses to bring the conditions in the body back to optimum levels

What is a receptor?

Cells which detect stimuli/ a change in the environment

What is an effector?

A muscle or gland that will bring about a response

What are the two types of effectors?

1. Muscles

2. Glands

What are the two parts of CNS?

1. Brain

2. Spinal cord

What is the role of each neurone:

1. Sensory neurone

2. Motor neurone

3. Relay neurone

1. Carry impulses from receptors to the CNS

2. Carry impulses from the CNS to effectors

3. Connect sensory and motor neurones inside the CNS

What is the order of information flow for a reaction to a stimulus?

Stimulus → receptor → sensory neurone → CNS → motor neurone → effector → response

Write the order of a reflex arc

stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response

What are some examples of reflexes?

1. Blinking

2. Breathing

3. Sneezing

What happens at a synapse?

1. Electrical impulses reaches the end of the neurone

2. This causes the release of a chemical neurotransmitter which diffuses across the gap

3. This triggers a new electrical impulse on the next neurone