topic 14 *2 Flashcards
synapse
junction between 2 neurones, allows an impulse to travel from axon terminal to a dendrite of a different neurone.
Central nervous system
(brain and spinal cord)- coordinates all reactions and nervous communications
Peripheral nervous system
nervous system outside of brain and spinal cord)- transmits impulses from CNS (Central Nervous System)
Reflex actions
keep you safe, The information needs to change to travel between neurons into chemical form, but it can travel in the neurone (which travel in blood) in an electrical form.
Complementary shapes help and allow receptor proteins to be able to transmit neurones to neurotransmitter molecules.
Sensory neurone-
transfer nerve impulses away from receptor cells when a stimulus is detected (hot pan), transmitted as a nerve impulse to central nervous system, can be long. Cell body found in lower middle.
Relay neurone-
connects one neurone to the next. Found in brain, makes links between sensory neurones and motor neurones in spinal cord, not long. Cell body found at top.
Motor neurones
transfer nerve impulses from brain or spinal cord to effectors like muscles or glands, can be long and connected to muscles. Cell body found at top.
At the end of neurones is a….. terminal
axon terminal which contains tiny bubble-like structures called vesicles containing neurotransmitters.
electrical impulses at axon terminal
As an electrical impulse arrives, vesicles containing neurotransmitters are stimulated and release these chemicals into the synaptic gap which is between neurones.
neurotransmitters diffuse accross
diffuse across the gap, binding with receptor proteins on the surface of the dendrites of the next neurone. If enough binding occurs an impulse is triggered. This is only in one direction.
Reflex arcs
straight to spinal cord, not brain): receptor (in skin)- sensory neuron- relay neurone- motor neurone- effector (muscle or skin)
order of nerones in reflex
sensory, relay, motor
