jubivuje's version from 2015-09-22 00:12

Section 1

Question Answer
What is a neurotransmitter and what does it do?A chemical substance released from the terminal ending of an axon in the synaptic cleft during the transmission of a nerve impulses, which relays information from one neuron to another
A neurotransmitter is a type of?Chemical messenger
Which neurotransmitter do the sympathetic nuerons releasenoradrenalin
Which neurotransmitter do the parasympathetic neurons releaseacetylcholine (ACh)
What is the significance of the division into sympathetic and parasympathetic branches of the ANS?One or the other branch of the system can dominate according to circumstances
At times of emergency which branch of the ANS is activated?The sympathetic branch wil be excited (activated) at times such as in 'fight or flight'
What happens to the parasympathetic ns at times of 'fight or flight'It is inhibited
Which part of the ANS is more dominant at times of rest?The parasympathetic branch will tend to dominate over the sympathetic branch
Which system controls the gutThe enteric system

Section 2

Question Answer
Where do the cranial nerves of the PNS feed into the brain
Where do the spinal nerves feed intothe spinal cord
What does the somatic nervous system do?Conveys sensory information to the CNS and effects voluntary actions via skeletal muscles
What does the ANS do?controls involuntary, internal state of organs

Section 3

Question Answer
What is a dendriteShort neuronal processes (extensions of the neuronal cell body) that conduct information towards the cell body of the neuron
Information is received by what?The dentrites
What is a glial cell?Non-neuronal cells
Name the glial cellsAstrocytes, microglia, oligodendrocytes, Schwann cells
What do glial cells do?Provide essentail supportive and nutritive functions towards neurons
what cells assist in the development and maintenance of the nervous system?Glial cells
What do astrocytes domaintain the integrity of a barrier between the circulating blood and the brain by the formation of high-resistance or 'tight' junctions
What do microglia cells doThey are found throughout the white and grey matter and defend the nervous system from infection and injury
What do Oligoendroctyes do?Form the lipid-rich insulting shealth around some neurons in the CNS (Myelin)
What do Schwann cells do?Myelination of neurons in the peripheral nervous system

Section 4

Question Answer
What does myelin dospeeds up the rate at which information is transmitted along axons
What occurs when there is a loss of myelin from nerve fibres (demyelination)Multiple sclerosis
What cells are effected by demyelinationThe white cells
What are actions potentialsbriefp ulses of electricity /nerve impulses that convey info along the length of a neuron
When neurons are transmitting information what are they said to be doingFiring

Section 5

Question Answer
What is a synapseThe junction between two neurons which allows the transfer of messages from one cell to another using neurotransmitters
What is a nueromuscular junctionThe junction between a neuron and a muscle fibre which allows the tranfser of messages from one cell to another using neurotransmitters
Name the important components of a synapsepresynaptic terminal, postsynaptic terminal, synaptic cleft
What is the synaptic cleftThe gap between the presynaptic membrane and the postsynaptic membrane
What happens in the synpatic cleftSignalling molecules pass (neurotransmitters)

Section 6

Question Answer
What does an agonist do?A chemical substance that mimics the physiologial effect of a natural chemical (e.g. neurotransmitter), by occupying the same receptors
What can occupy the receptors of a neurotransmitter and 'mimic' the effect of the natural neurotransmitter?An agonist
What does and antagonist do?A chemical substance that BLOCKS the physiological effects of a natural chemical (e.g. neurotransmitter) and upon binding to the receptor, blocks both its occupation and its effect
What can block the natural transmitters occupation and action but has no effect on the cell?Antagonist

Section 7

Question Answer
How is information carried along the axon of a neuron?In the form of action potential frequency
How is an action potential generated?The rapid flow of sodium and potassium ions across the neuron cell membrane causing localized changes in voltage across the membrane. A short-term change in the electrical potential on the surface of a cell (e.g. a nerve cell or muscle cell) in response to stimulation, and then leads to the transmission of an electrical impulse (nerve impulse) that travels across the cell membrane.
How are action potentials conveyed between neurons?Across the gap between neurons (synapse) by means of neurotransmitter molecules
How are action potentials conveyed between neuron and muscleAcross the neuromuscular junction by means of neurotransmitter molecules
Where are neurotransmitter molecules stores?At the terminal of a neuron
When are neurotransmitters releasedIn response to the arrival of an action potential
How is a neuron characterizedBy the neurontransmitter it synthesizes, stores and releases in a synapse
What are the effects of different neurotransmitters?excitation (fires) or inhibition - depending on the properties of the combination of neurotransmitter and its receptor