The Nervous System

Question 1

Nervous system

Answer 1

Consists of the central nervous system and the peripheral nervous system.

Question 2

Central nervous system (CNS)

Answer 2

Consists of the brain and the spinal cord and is the origin of all complex commands and decisions. It passes messages to and from the brain and connects nerves to the peripheral nervous system

Question 3

Brain

Answer 3

The centre of all conscious awareness. The cerebral cortex is highly developed in humans and is what distinguishes peoples higher mental functions from those of animals. It is divided into two hemispheres.

Question 4

Spinal cord

Answer 4

An extension of the brain. It is responsible for reflex actions such as pulling a hand away from a hot plate

Question 5

Peripheral nervous system (PNS)

Answer 5

Sends information to the central nervous system from the outside world and transmits messages from the central nervous system to muscles and glands in the body. It does this via millions of neurons (nerve cells) and is divided into the autonomic nervous system and somatic nervous system

Question 6

Somatic nervous system (SNS)

Answer 6

Transmits information from receptor cells in the sense organs to the central nervous system. It also receives information from the central nervous system that directs muscles to contract. It controls muscle movement and receives information from sensory receptors.

Question 7

Autonomic nervous system (ANS)

Answer 7

Transmits information to and from internal bodily organs. It is ‘autonomic’ as the system operates involuntarily. It has two main divisions: the sympathetic and parasympathetic nervous systems. It governs vital functions of the body such as breathing, heart rate, digestion, sexual arousal and stress responses.

Question 8

Parasympathetic nervous system

Answer 8

A division of the autonomic nervous system which controls the relaxed state (rest and digest), conserving resources and promoting digestion and metabolism. The parasympathetic branch works in opposition to the sympathetic branch of the autonomic nervous system

Question 9

Sympathetic nervous system

Answer 9

A division of the autonomic nervous system which activates internal organs for vigorous activities and emergencies, such as the fight or flight response. It consists of nerves that control, for example, increased heart rate and breathing, and decreased digestive activity. The sympathetic branch works in opposition to the parasympathetic branch of the autonomic nervous system