B13.1 Coordination and response

STIMULUS

A change in the environment that triggers a response.

RECEPTOR

A type of cell in an organ that detects a change in the environment.

COORDINATOR

Processes information and decides what to do before a response is made.

EFFECTOR

Corrects a change in the environment to directly cause a response.

CENTRAL NERVOUS SYSTEM (CNS)

The brain and spinal cord.

PERIPHERAL NERVOUS SYSTEM

All the nerves that originate from the spinal cord and lead to other organs.

SENSORY

A type of neurone that carries impulses from receptor cells to the coordinator.

RELAY

A type of neurone that carries impulses from a sensory neurone to a motor neurone.

MOTOR

A type of neurone that carries impulses to an effector.

GLAND

An effector can be a muscle or this.

REFLEX ARC

The pathway taken by impulses when standing on a sharp pin.

SPINAL CORD

The coordinator in reflex actions.

INVOLUNTARY

Reactions that we are not consciously aware of that can involve the central nervous system or just the spinal cord.

VOLUNTARY

Reactions that we are consciously aware of that involve the central nervous system.

AXON

A threadlike extension of a neuron that carries nerve impulses away from the cell body.

NEURONE

A nerve cell.

TRUE

All reflex actions are involuntary actions.

FALSE

All involuntary actions are reflex actions.

IMPULSES

These are produced by receptor cells when a change in the environment is detected.

MESSAGES

Never use this word in an exam to describe electrical impulses!

ELECTRICAL

The type of energy that is carried in neurones to transmit information.

TOUCH

Neurones never ______________ each other.

SYNAPSE

A gap between two neurones.