B10- the human nervous system Flashcards
what is a neurone?
Nerve cell; specialised to transmit electrical impulses
Sensory neurone
The nerve cell that transmits electrical impulses from receptors in the sense organs to the CNS.
motor neurone
The nerve cell that carries electrical impulses from the CNS to effectors
Relay neurone
The nerve cell that transmits electrical impulses from sensory neurones to motor neurones
stimulus
any change in the environment
receptor
Organ that detects a change in the environment
Effector
muscles or glands, which bring about response which restore optimum levels
central nervous system
the brain and spinal cord
reflex
Automatic and rapid response to a stimulus.
synapse
A tiny gap between 2 nerves in which the impulse must pass
what is the order?
stimulus ->receptor->coordinator->effector->response
reflex actions
are automatic and rapid, do not involve the conscious part of the brain
give two ways un which a reflex action is different from an action controlled by hormones
a reflex action is rapid as it involves the unconscious part of your brain
reflex action involves electrical impulses whereas hormones involve chemicals
explain the reflex arc
1)Receptor in the skin detects a stimulus (the change in temperature).
2)Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS. Relay neurons connect sensory neurons to motor neurons.
3)Motor neuron sends electrical impulses to an effector.
4)Effector produces a response (muscle contracts to move the hand away).