Nervous System Organistation

Question 1

Central Nervous System (CNS)
Peripheral Nervous System (PNS)

Answer 1

CNS consists of the brain and spinal cord
-PNS consists of the neurones that transmit impulses to and from the central nervous system

Question 2

Examples of how the PNS is used

Answer 2

-Sensory neurones are used to transmit impulses from receptors to the CNS
-Motor neurones are used to transmit impulses from the CNS to effectors such as muscles
-Sensory neurones and motor neurones form the peripheral nervous system (PNS)

Question 3

We can also divide the nervous system into two parts based on function…

Answer 3

-Somatic (voluntary) nervous system
-Autonomic nervous system

Question 4

Somatic Nervous system + acetylcholine

Answer 4

-Involves functions that are under our conscious control
-e.g contracting a skeletal muscle
-When an impulse reaches the skeletal muscle, the neurotransmitter acetylcholine is released at the neuromuscular junction

Question 5

Autonomic nervous system

Answer 5

-regulates processes that are under unconscious control
-e.g regulation of heart rate and release of hormones

Question 6

Further divisions of the autonomic nervous system

Answer 6

-Sympathetic
-Parasympathetic

Question 7

Sympathetic nervous system (SNS) + Fight of Flight response

Answer 7

-SNS often increases the activity of target
Fight or flight response:
-SNS triggers heart rate to increase
-increasing supply of blood to the muscles
-breathing rate triggered to increase and muscles in the airway relax causing the airway to dilate
-increased oxygen supply to muscles and speeds up removal of co2
-triggers peristalsis in the digestive system to slow down, conserving energy for the stressful situation

Question 8

Parasympathetic Nervous system

Answer 8

-PNS generally decreases the activity of target organ
-For example during sleep it reduces breathing and heart rate and increases the activity of the digestive system