Divisions of the nervous system

Question 1

What is the nervous system (macro level)?

Answer 1

• Specialised set of cells
• Primary internal communication system
• Made up billions neurons
• Brain central part of nervous system

Question 2

What is the brain’s 2 functions?

Answer 2

1. Collect process & respond to info in environment
2. Direct working of different organs & cells in body

Question 3

What is the structure of the nervous system?

Answer 3

• Separated into central nervous system (CNS) & Peripheral nervous system (PNS)
• CNS separated into Brain & Spinal Cord (connects brain & nervous system)
• PNS separated into somatic nervous system & autonomic nervous system (ANS)
• ANS separated into sympathetic & parasympathetic nervous systems

Question 4

What is the purpose of the spinal cord in the CNS?

Answer 4

• Carries messages (using neurons) to & from the brain to PNS
• Spinal cord relays info
• Allows brain to monitor bodily processes e.g. breathing & digestions

Question 5

What’s an arc reflex?

Answer 5

• Receptor in skin senses stimulus (e.g. heat)
• Sensory neuron sends electrical impulses to a relay neuron (located in spinal cord)
• Motor neuron sends electrical impulses to an effector
• Effector produces response (muscle contracts to move hand away from heat)

Question 6

What is the PNS for?

Answer 6

• All nerves in body outside of CNS include the PNS
• Function to relay impulses from CNS to rest of body & vice versa
• Allows CNS to control various response systems

Question 7

What 2 parts make up the PNS?

Answer 7

• Somatic nervous system
• Autonomic nervous system

Question 8

Explain the somatic nervous system?

Answer 8

• Made up of 12 pairs of cranial nerves & 31 pairs of spinal nerves
• Connects CNS to our senses
• Contains sensory & motor neurons
• Under conscious control to control skeletal muscles & movement
• Control centre: Motor & somatosensory cortex
• Sensory afferent (outside in) pathways
• Sensory afferent means to transmit & receive info from senses
• e.g. visual info (eyes) & auditory info (ears) to the brain (using sensory neurons)
• Motor efferent pathways direct voluntary movement of skeletal muscles & orchestrate all movement from the brain (using motor neurons)

Question 9

Explain the autonomic nervous system?

Answer 9

• Keeps the body in a regular stable state (homeostasis)
• e.g. control heart rate, perspiration, digestion, temperature
• Uses automatic control
• Uses only Motor neurons to control internal organs/glands
• Its control centre: hypothalamus & pituitary gland (top of brain stem)
• 2 branches of ANS: Sympathetic & parasympathetic
• Both regulate same organs but have opposite effects e.g. adrenal gland during f/f response