PYC1501 HUMAN NERVE SYSTEM QUIZ QUESTIONS WITH CORRECT ANSWERS

PYC1501 HUMAN NERVE SYSTEM QUIZ QUESTIONS WITH CORRECT ANSWERS Main parts of the neuron - ANSWERS soma (cell body), axons (transmit info), dendrites (receive info) axon terminals (conduct messages) Function of a neuron - ANSWERS Convey a message The Dendrites - ANSWERS Branch like extensions of the cell body, allows neurons to connect to a large no of other neurons. The cell body (soma) - ANSWERS Soma receives messages from other neurons through the dendrites Soma has one other extension called the axon Axon - ANSWERS When the stimulation reaches a point the axon hillock initiates an impulse that runs along the >>>> fatty myelin sheath - ANSWERS Axons are enclosed in it Insulates the axon Separated by small gaps called nodes of Ranvier Conducts impulse much faster Impluse jumps from node to node Axon terminal (telondendria) - ANSWERS Ends in a small node called Bouton terminal Bouton terminal - ANSWERS Contains tiny containers called vesicles fill with neurotransmitters. Chemical substances that play a roll in conducting a message Synapse cleft - ANSWERS The gap at the junction of the synapse. Neurotransmitters - ANSWERS Regulate the communication between neurons sensory neurons (afferent) - ANSWERS carry information from the senses to the brain motor neurons (efferent) - ANSWERS Conduct messages from the spinal cord and the brain to the muscles and glades Nerve tract - ANSWERS When the nerve is in the spinal cord or brain Nerve - ANSWERS When the nerve is in parts of the body (excluding brain/spinal cord Impulse conduction - ANSWERS process by which messages are relayed in neurons, from one neuron to the next Electrical impulse - ANSWERS Begins in the first segment of the axon Travels down the axon to the terminals because of electrical events at the cell membrane Chemical impulse - ANSWERS determines if the impulse will be conducted across the gap resting membrane potential - ANSWERS the electrical charge of a neuron when it is not active but polarised Cell Membrane - ANSWERS contains a mechanism that allows some ions through and prohibits others When a neuron is ready - ANSWERS + outside - inside absolute refractory period - ANSWERS neuron doesnt respond to any stimulus Axon cannot conduct an impulse Refractory period - ANSWERS the membrane returns the soduim and potassium ions to the original states pumps potassium inside/soduim outside refractionary period - ANSWERS prevents the nervous systems from over stimulation characteristics of impulse conduction - ANSWERS once impulse is initiated at the axon hillock it is rapidly conducted along the axon it propagates down the axon from the axon hillock to the axon terminals Nodes of ravier - ANSWERS these gaps separate the sheaths and contain the sodium and potassium ion channels required for impulse conduction salutatory conduction - ANSWERS myelinated axon impulse conduction is known as action potential conduction - ANSWERS unmyelinated axon impulse conduction is known as Conduction - ANSWERS >>> of a nerve impulse in a neuron is primarily electrical communication - ANSWERS between different neurons is primarily chemical presynaptic membrane - ANSWERS membrane of axon terminal postsynaptic membrane - ANSWERS membrane of the soma/dendrite Synapse - ANSWERS presynaptic + postsynaptic + synaptic cleft spatical summation - ANSWERS occurs when a post potential is reinforces by AP from the terminals of several axons reaching the synapse at the same time Ap is reinforced - ANSWERS because more of the transmitter is released and accumulates in the synaptic cleft, strenghtening the post potential temporal summation - ANSWERS occurs when the same axon discharges repeatedly also causing the release and accumulation of more of the neurotransmitter in the synaptic cleft