nervous + endocrine system (AO1 only)

Question 1

what is the nervous system and what does it do?

Answer 1

• Our primary internal communication system
• Collects processes and responds to information in the environment
• Co-ordinates the working of organs and cells in the body

Question 2

What are the two types of NS?

Answer 2

• central nervous system (CNS)
• peripheral nervous system (PNS)

Question 3

What is the CNS made up of and what does it do?

Answer 3

• Brain and spinal cord
• The spinal cord is an extension of the brain. It is responsible for reflex actions e.g. pulling your hand away from a hot plate.
• The CNS passes messages to and from the brain and also to and from the PNS.

Question 4

What does the PNS do?

Answer 4

Transmits messages via millions of neurons to and from the CNS.

Question 5

What is the PNS made up of?

Answer 5

• Autonomic Nervous System (ANS)
• Somatic Nervous System (SNS)

Question 6

What does the autonomic nervous system (ANS) do?

Answer 6

controls vital bodily responses e.g. stress response

Question 7

what does the somatic nervous system (SNS) do?

Answer 7

controls muscle movement (voluntary movement) and receives info from sensory receptors.

Question 8

What is the endocrine system made up of?

Answer 8

hormones and glands

Question 9

What does the endocrine system do? + examples

Answer 9

• Key in homeostasis/regulation of bodily functions
• Hormones are chemicals produced by endocrine glands (e.g. the pituitary gland, the ovaries, the testes).
• Ovaries produce oestrogen to regulate the menstrual cycle
• Testes produce testosterone - male sexual behaviour and aggression
• In response to a direct signal from the brain, hormones are secreted into our systems from our endocrine glands via the bloodstream.
• The endocrine system acts much more slowly than the nervous system but has very widespread and powerful effects.

Question 10

How does the ANS and endocrine system work together? (what is the fight or flight response)? (sympathetic response)

Answer 10

• When a stressor is detected by the hypothalamus, a rapid response is executed by your body.
• The hypothalamus activates the sympathetic branch (in sympathy with your fear) of your ANS.

Question 11

What is the order of the fight or flight response? (sympathetic response)

Answer 11

1. hypothalamus
2. adrenal medulla
3. adrenaline/noradrenaline
4. bodily organs
5. increased HR, BR (oxygen), BP, pupils dilate, digestion stops
6. fight or flight (sympathetic response)

Question 12

What happens once the threat is passed?

Answer 12

• the parasympathetic response returns the body to its normal state
• BR, BP, HR all normalise
• Pupils go back to normal
• Digestion resumes