nervous system

Question 1

nervous system

Answer 1

specialised network of neurons in the human body and is our primary internal communication system i.e. allows brain, spinal cord, body to communicate

Question 2

functions of nervous system

Answer 2

• collect, process, respond to information in the environment
• coordinate the working of different organs and cells in the body

Question 3

subsystems of nervous system

Answer 3

• central nervous system
• peripheral nervous system

Question 4

subdivisions of CNS

Answer 4

• brain
• spinal cord

Question 5

subdivisions of PNS

Answer 5

• somatic nervous system
• autonomic nervous system (sympathetic and parasympathetic nervous systems)

Question 6

functions of CNS

Answer 6

• control of behaviour
• regulation of body’s physiological processes
• brain must receive information from sensory receptors and send messages to muscles and glands in the body via spinal cord

Question 7

the brain’s role in the CNS

Answer 7

• brain is centre of all conscious awareness
• brain’s outer layer- cerebral cortex/cerebrum is highly developed in humans and is what distinguishes our higher mental functions from those of animals

Question 8

spinal cord’s role in CNS

Answer 8

• spinal cord is collection of nerve cells attached to the brain and run the length of the spinal column
• main function is to relay information between brain and rest of the body
• allows brain to monitor and regulate bodily processes and control voluntary movement
• spinal cord is connected to different parts of the body by pairs of spinal nerves which connect to specific muscles/glands
• contains circuits of nerve cells that allow us to perform simple reflexes without direct involvement of the brain

Question 9

peripheral nervous system

Answer 9

• All neurons (nerve cells) outside the CNS make up the peripheral nervous system
• function is to relay nerve impulses (messages) from the CNS (the brain and spinal cord) to the rest of the body and from the body back to the CNS

Question 10

somatic nervous system

Answer 10

• subdivision of the PNS
• made up of sensory and motor neurons
• Sensory neurons in SNS receive information from the sensory receptors and relay these messages to the CNS
• Therefore, SNS connects the CNS to the senses
• Motor neurons in SNS relay messages from the CNS to other areas of the body, and so control voluntary muscle movement
• SNS also involved in reflex actions, which allows the reflex to occur very quickly

Question 11

autonomic nervous system

Answer 11

• governs internal organs and glands of vital functions of the body without our conscious awareness (e.g. breathing, heart rate, digestion, sexual arousal and stress responses).
• involuntary actions are regulated by ANS
• ANS is necessary because vital bodily functions such as heartbeat and digestion would not work so efficiently if you had to think about them
• made up of motor neurons only
• ANS is subdivided into sympathetic and parasympathetic nervous systems
• Both of these divisions tend to regulate the same organs but have opposite effects
• usually in balance, but under certain circumstances the balance shifts and one branch becomes more dominant

Question 12

sympathetic nervous system

Answer 12

• primarily involved in responses that help us to deal with emergencies
• responds to a perceived threat.
• Neurons from SNS travel to virtually every organ and gland within the body to produce physiological changes that prepare the body for fight or flight
• E.g. pupils dilate, causes the body to release stored energy, heart rate and breathing increase, non-vital functions are inhibited e.g. digestion and urination

Question 13

parasympathetic nervous system

Answer 13

• restores normal physiological functioning when threat has passed
• E.g. heart rate and breathing slow down, blood pressure is reduced, digestion begins (conservation)
• rest and digest system