3.3 receptors and reflexes

define receptor

structure that is bale to detect a change in external or internal environment

name the different types of receptors

thermoreceptorrs, osmoreceptors, chemoreceptors, touch receptors, pain receptors

define stimuli

any change internal/external that causes a response

define reflex

a rapid automatic response to a change in the external/internal environment; tries to restore homeostasis

4 important properties of reflexes

stimulus is required to trigger a reflex, its involuntary, rapid, stereotyped (occurs the same way each time)

define a reflex arc

the pathway a nerve impulse follows in travelling from a receptor to an effector

what are the components/steps of a reflex arc

1. a receptor reacts to change in the environment by initiating a nerve impulse in a sensory neuron

2. sensory neuron carries nerve impulses to the spinal cord/brain

3. the nerve impulse is either directly passed to a motor neuron or goes through an inter neuron first

4. motor neuron carries impulse to an effector (muscles/glands)

5. effector receives nerve impulse and will react to the change.