Nervous system

Question 1

What is the nervous system?

Answer 1

• Specialised network of nerve cells in the human body made up of the PNS & CNS
• primary internal communication between neurons which uses electrical & chemical signals
• allows the brain, spinal cord & rest of body to communicate

Question 2

What are the two main functions of the nervous system?

Answer 2

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

Question 3

What are the two subsystems of the nervous system?

Answer 3

• Central nervous system (CNS)
• Peripheral nervous system (PNS)

Question 4

What is the CNS made up of?

Answer 4

The brain and spinal cord

Question 5

What is the brain?

Answer 5

• centre of all conscious awareness
• the cerebral cortex is highly developed in humans
• coordinates sensation, intellectual & nervous activity
• The brain is divided into two hemispheres

Question 6

What is the spinal cord & role?

Answer 6

• An extension of the brain
• It passes messages to and from the brain
• connects nerves to the PNS
• responsible for reflex actions

Question 7

What is the job of the PNS?

Answer 7

• Transmits messages via neurons to the CNS from the outside world and from the central nervous system to muscles and glands

Question 8

What is the PNS further subdivided into?

Answer 8

• Autonomic nervous system
• somatic nervous system

Question 9

What are the functions of the Autonomic nervous system?

Answer 9

• Associated with involuntary (vital) actions E.g. breathing, heart rate, digestion etc.
• consist of motor pathways > which allows brain to control movement
• controls internal organs and glands
• has 2 further components (SNS, PSN .S)

Question 10

What are the functions of the somatic nervous system?

Answer 10

• Carries sensory information from sense/body receptors to the brain and provides muscle responses via the motor pathways (sensory & motor pathways)
• transmits information from the brain to effectors to produce voluntary actions e.g. eating, walking (conscious control)
• controls skeletal muscle and movement
• some movemnts involuntary > reflex arc

Question 11

What is the autonomic nervous system further divided into?

Answer 11

• Sympathetic nervous system
• Parasympathetic nervous system

Question 12

What is the role of the sympathetic nervous system?

Answer 12

• prepares body for flight or fight by releasing adrenaline which changes body from resting state to state of physiologically arousal due to perceived threat
  e.g. increased heart/ breathing rate, pupil dilation, decreased food digestion, decreased saliva production, increased muscle tension, increased sweat production

Question 13

What is the role of the parasympathetic nervous system?

Answer 13

• ‘rest and digest response’
• when threat has passed, PSN calms the body from physiological aroused state to resting state > restores bodies normal functioning