The nervous system: Homeostasis and response: Biology: GCSE (9:1)

Nervous system

The network of nerve cells and fibres that transmits nerve impulses between parts of the body

Neurones

Basic cells of the nervous system that carry electrical impulses around the body

Electrical impulses

The impulses or signals that are carried by neurones

Central nervous system (CNS)

The brain and the spinal cord

Peripheral nervous system

The parts of the nervous system outside of the brain and spinal cord such as the sensory and motor neurones

Stimulus

A change in an organism's surroundings

Receptors

Special structures that allow living organisms to sense the conditions of their internal or external environment

Sensory neurone

A neurone that carries impulses from the sensory organs to the central nervous system

Coordinator

The central nervous system which formulates a response to a stimulus before sending impulses to an effector

Motor neurone

A neurone that sends impulses from the CNS to an effector

Effector

A structure that acts in response to a stimulus such as muscles which contract or glands which secrete hormones

Response

A reaction to a stimulus

Reflex arc

A shorter nerve pathway involved in a reflex action made up of a sensory neurone, relay neurone and a motor neurone

Relay neurone

A short type of neurone that is involved in reflex actions and is found in the spinal cord

Reflex response

A quick and involuntary reaction to a stimulus such as moving a hand away from a hot object

Synapse

A junction or gap between neurones where information in chemical form is transmitted from one neurone to the next

Neurotransmitter

A chemical that is released from the ends of an active neurone and diffuses across the synapse to other neurones