13.6 Organisation of the Nervous System

Question 1

How is the mammalian nervous system structurally organised?

Answer 1

CENTRAL NERVOUS SYSTEM (CNS) - brain + spinal cord

PERIPHERAL NERVOUS SYSTEM (PNS) - all neurones connecting CNS to rest of body

Question 2

What is the central nervous system?

Answer 2

consists of brain + spinal cord

Question 3

What is the peripheral nervous system?

Answer 3

consists of all neurones

connecting CNS to rest of body

Question 4

What is the difference between the peripheral & central nervous system?

Answer 4

peripheral nervous system consists of all neurones connecting CNS to rest of body

central nervous system consists of brain & spinal cord only

Question 5

How is the mammalian nervous system functionally organised?

Answer 5

SOMATIC NERVOUS SYSTEM - under conscious control

AUTONOMIC NERVOUS SYSTEM - under subconscious control

Question 6

What is the somatic nervous system?

Answer 6

part of nervous system

which is under conscious control

Question 7

What is the autonomic nervous system?

Answer 7

part of nervous system

which is under subconscious control

Question 8

What type of actions is the somatic nervous system responsible for?

Answer 8

conscious actions

e.g movement of arm muscle

Question 9

What type of actions is the autonomic nervous system responsible for?

Answer 9

subconscious actions

e.g beating of heart, peristalsis, contraction of smooth muscle

Question 10

What is the autonomic nervous system divided into?

Answer 10

SYMPATHETIC - initiates “fight or flight” responses, uses noradrenaline neurotransmitter

PARASYMPATHETIC - relaxing responses, uses acetylcholine neurotransmitter

Question 11

What is the sympathetic nervous system responsible for?

Answer 11

initiating “fight or flight” responses

e.g decreasing peristalsis, decreasing saliva production, relaxing bronchial muscle, decreasing urine production

Question 12

What is the parasympathetic nervous system responsible for?

Answer 12

initiating relaxing responses

e.g increase digestion, increase urine secretion, increase saliva production, contraction of bronchial muscle

Question 13

Which activities may the sympathetic nervous system be responsible for initiating?

Answer 13

stimulates fight-or-flight responses & relaxes non-fight-or-flight responses:

• DECREASING PERISTALSIS
• DECREASING SALIVA PRODUCTION
• RELAXING BRONCHIAL MUSCLE
  
  • increased rate of ventilation to provide O₂ for aerobic respiration
• DECREASING URINE PRODUCTION

Question 14

Which activities may the parasympathetic nervous system be responsible for initiating?

Answer 14

stimulates non-fight-or-flight responses / relaxes fight-or-flight responses

• INCREASING DIGESTION
• INCREASE URINE SECRETION
• CONTRACTION OF BRONCHIAL MUSCLE
• INCREASE SALIVA PRODUCTION

Question 15

Which neurotransmitter does the sympathetic nervous system use?

Answer 15

noradrenaline

Question 16

Which neurotransmitter does the parasympathetic nervous system use?

Answer 16

acetylcholine

Question 17

Which system are relay neurones a part of?

Answer 17

CNS, central nervous system

∵ relay nerones are found within the brain and spinal cord

Question 18

Which system are motor & sensory neurones a part of?

Answer 18

PNS, peripheral nervous system

∵ they connect CNS to rest of the body (receptors & effectors)

Question 19

Which neurotransmitter does the somatic nervous system use?

Answer 19

acetylcholine

Question 20

Why can some autonomic functions be controlled by the somatic nervous system?

Answer 20

depending on context, the autonomic function may not need to be carried out in the normal way. ∴ requires somatic system to regulate.

e.g breathing can be controlled so a person can hold their breath underwater, since not able to breathe normally in this situation.