coordination and response (topic 14) Flashcards
stimulus
A change in the environment that can be detected by an organism.
nervous system
An organ system consisting of the brain, spinal cord and neurones. It responds quickly to changes inside and outside of the body.
neurones
nerve cells in which nerve impulses travel along as electrical impulses
what composes the mammalian nervous system
cns and pns
cns
central nervous system
-brain and spinal cord
-responsible for coordinating all reactions and nervous communication around the body.
pns
peripheral nervous system
-all nerves which arent in the spinal cord or brain
responsible for transmitting the impulses from the CNS to all parts of the body.
what is the role of the nervous system
coordination and regulation of body functions
what are the three main types of neurones
sensory, relay, motor
structure of a sensory neurone
long cell body in the middle of the neurone
strcuture of relay neurone
short, cell body
strucutre of motor neurone
long, cell body at the end
sensory neurones
receive impulses from receptor cells, because of a stimulus, and carries impulse towards cns
relay neurones
make link between sensory and motor neurone
motor neurone
transfer nerve impulses from brain or spinal cord to effectors eg. muscles or glands for a dedicated response
what is a sysnapse
a junction between two neurones
allows an impulse to travel from an axon terminal of one neurone to a dendrite in another neurone
axon terminal
end of an axon in a neurone that releases neurotransmitters from vesicles into the synaptic gap.
dendrite
Further branches at the end of dendrons in a neurone that receive signals from other neurones via the synapse.
what do axon terminals contain
many vessicles which contai neurotransmitters
what do dendrites contain
receptor molecules that bind to these neutrotransmitters
what happens when a nerve impulse arrives at the axon terminal
- vesicles release neurotransmitters into synaptic clef
- neutrotransmitters travel along gap by diffusion
3.neurotransmitter bind with receptor molecules on dendrite
4.nerve impulse triggered in this neurone
reflex action
A means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands).
involuntary action, rapid, automatic, innate
reflex arc
Pathway through the body that brings about a reflex action.
reflex arc path
receptor → sensory neurone → relay neurone → motor neurone → effector
what are receptors
cell that detects stimulus, make connections with sensory neurones