PYC1501 HUMAN NERVE SYSTEM questions and complete answers

Main parts of the neuron Correct answers soma (cell body), axons (transmit info), dendrites (receive info) axon terimals (conduct messages) Function of a neuron Correct answers Convey a message The Dendrites Correct answers Branch like extensions of the cell body, allows neurons to connect to a large no of other neurons. The cell body (soma) Correct answers Soma receives messages from other neurons through the dendrites Soma has one other extension called the axon Axon Correct answers When the stimulation reaches a point the axon hillock initiates an impulse that runs along the fatty myelin sheath Correct 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) Correct answers Ends in a small node called Bouton terminal Bouton terminal Correct answers Contains tiny containers called vesicles fill with neurotransmitters. Chemical substances that play a roll in conducting a message Synapse cleft Correct answers The gap at the junction of the synapse. Neurotransmitters Correct answers Regulate the communication between neurons sensory neurons (afferent) Correct answers carry information from the senses to the brain motor neurons (efferent) Correct answers Conduct messages from the spinal cord and the brain to the muscles and glades Nerve tract Correct answers When the nerve is in the spinal cord or brain Nerve Correct answers When the nerve is in parts of the body (excluding brain/spinal cord Impulse conduction Correct answers process by which messages are relayed in neurons, from one neuron to the next Electrical impulse Correct 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 Correct answers determines if the impulse will be conducted across the gap resting membrane potential Correct answers the electrical charge of a neuron when it is not active but polarised Cell Membrane Correct answers contains a mechanism that allows some ions through and prohibits others When a neuron is ready Correct answers + outside - inside absolute refractory period Correct answers neuron doesnt respond to any stimulus Axon cannot conduct an impulse Refractory period Correct answers the membrane returns the soduim and potassium ions to the original states pumps potassium inside/soduim outside refractionary period Correct answers prevents the nervous systems from over stimulation characteristics of impulse conduction Correct 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 Correct answers these gaps separate the sheaths and contain the sodium and potassium ion channels required for impulse conduction salutatory conduction Correct answers myelinated axon impulse conduction is known as action potential conduction Correct answers unmyelinated axon impulse conduction is known as Conduction Correct answers of a nerve impulse in a neuron is primarily electrical communication Correct answers between different neurons is primarily chemical presynaptic membrane Correct answers membrane of axon terminal postsynaptic membrane Correct answers membrane of the soma/dendrite Synapse Correct answers presynaptic + postsynaptic + synaptic cleft