Coordination and Response Flashcards
what is a nervous system
coordinates and regulates body function
describe the mammalian nervous system
- the central nervous system (CNS) consisting of the brain and the spinal cord
- the peripheral nervous system (PNS) consisting of the nerves outside of the brain and spinal cord
types of neurons
motor neuron, relay neuron and sensory
what is a motor neurone
long and have a cell body at one end with long dendrites branching off. Carry impulses from the CNS to muscles and glands
cell body
controls the metabolism of nerve cell
dendrites
‘collect’ information from other cells
axon
a long fibre which carries information away from the cell body, sometimes over long distance
fatty sheath made of myelin
gives electrical insulation between neighboring cells and speeds up transmission
end plate
synapses with another nerve cell, a muscle or a gland
what is a sensory neurone
long and have cell body branching off the middle of an axon. Carry impulses from the sense organ to the CNS
what is a relay neurone
short and are located in the CNS, connecting sensory and motor neurones
what’s a reflex action
a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands)
example of reflex action
moving you hand away from a hot object, coughing, pupil contraction, knee jerk
what’s a reflex arc
the nerve pathway involved in the reflex action
spinal reflex neurone pathway
receptor to sensory neurone to relay neurone to motor neurone to motor neurone to effector (muscle or gland)
what is a nerve impulse
an electrical signal that passes alone neurones. also called action potential
what is a synapse
junction between two neurones between axon terminal of one neurone and dendrite of next
what occurs in the synapse
- impulse goes down neurone
- vesicles with NT move to membrane and fuse with it
- NT is released
- NT diffuses across synaptic gap
- NT binds to a specific protein receptor on the membrane of post-synpatic neurone
- impulse generated in post- synpatic neurone
what are sense organs
groups of receptor cells that detect and respond to specific stimuli
e.g. light, sound touch, temperature, chemicals
examples of sense organs
eyes,ears,skin,nose,tongue
what are receptors
the structure that detects the stimulus
examples of receptors
photoreceptors - light
chemoreceptors (tongue) - chemicals
thermoreceptors (skin) - temperature change
what are transducers
they convert one type of energy (light) into chemical energy of a nerve impulse
cornea
transparent layer- refracts light
