neurons and synaptic transmission Flashcards
what is a neuron
A nerve cell which proccesses and transmits messages through electrical and chemical signals
what is a synapse
A gap in the neruon chain
what components are in the ctructure of a neuron
-Cell body
-Nucleus
-Dendrites
-Axons
-Myelin sheath
-Nodes of ranvier
-Terminal button
what is the cell body
contains nucles
what is the nucleus
contians cells DNA
waht are denrdrites
carry nerve impulses from neighbouring neurons toward the cell body
what are axons
carriers electrical impulses away from cell body
what is the myelin sheath
protects axon and speeds up eletrical transmission of impulses
what are nodes of ranvier
gaps between the myelin sheath whcih speeds up transmission as impulse is forced to jump the gap
what is he terminal button
at the end of an axon, communicates with the next neuron in the chani acorss the synapse
what are the three types of neurons
-Sensory neuron
-Relay neuron
-Motor neuron
what is a sensory neuron
-located outside of NCS in the PNS they are found in clusters (ganglia)
-Long dendrites
-Short axons
-Carry messages from PNS to CNS
-When nerve impulses reach brain they are translated to sensations
-Some neurones don’t reach the brain but stop at spinal cord allowing for reflex actions
what is a relay neuron
-Located in brain and visual system
-Short dendrites
-Short axons
-Connect sensory neurons to motor neurons and other relay neurons
-Make up 97% of all neurons
-Axons are NOT surrounded by myelin sheath
what is a motor neruon
-Located in CNS but have long axons which from part of PNS
-Long axons
-Short dendrites
-Connect CNS to effects eg. muscles
-When stimulates release neurotransmitters that bind to receptors on muscles to trigger movement
