Chapter 10

Question 1

What is homeostasis?

Answer 1

regulating internal conditions to keep them at an optimum, despite internal and external changes. Maintains optimum conditions for enzymes

Question 2

What are some of the homeostasis in the body?

Answer 2

• blood pressure

- body temperature

Question 3

What does the nervous use?

Answer 3

it uses electrical impulses to bring about fast, but short-lived Reponses

Question 4

What does the nervous system consist of?

Answer 4

• the brain and spinal cord, which make up central nervous system (CNS)
• neurones

Question 5

How does the information pass through the nervous system?

Answer 5

through neurones,

• an electrical impulse arrives at the synapse (gap between 2 neurones)
• neurotransmitter molecules are released and diffuse across the synapse
• neurotransmitter molecules fill receptors and cause an electrical impulse in the next neurone

Question 6

What is a reflex action?

Answer 6

a fast automatic reaction. Does not involve thinking parts of the brain

Question 7

What are the 7 stages of the reflex arc and what do they do?

Answer 7

• stimulus = a change in the environment
• receptor = detects a stimulus
• sensory neurone = transmits electrical impulse travels to the CNS
• relay neurone = in the spinal cord. Transmits electrical impulses from sensory neurone to the motor neurone
• motor neurone = transmits impulses from CNS to effector
• effector = produces a response. Can be a muscle or gland
• response = the change in response to the stimulus

Question 8

How does the body monitor/maintain our body temperature?

Answer 8

the temperature receptors in skin detect changes in the external temperature. they pass the information to the processing centre in the brain called - hypothalamus.
The processing centre also has temperature receptors to detect changes in the temperature of the blood. The centre automatically triggers changes to the effectors to ensure our body temperature remains constant at 37°C.