NERVES

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DRAW the sensoryand motor neurones on the back of this card
Labels: SENSORY= Dendron, Axon, Small Cell body, Receptor, Dendrites, direction of transmission.MOTOR= Large cell body, Dendrites, Myelin sheath,nodes ofranvier
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What differences in structure and function are there between myelinated and non myelinated neirones
Myelinated= faster transmission of action potential. Long distance signals, more rapid resonse. NON= shorter distance, body function co ordination eg breathing and digestive system
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Describe the structure of the cholinergic synapse
Neurotransmitter: Acetylcholine(within vesicles). Many mitochondria. Voltage gated calcium channels. Axon and myelin sheath at top
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What is the role of neurotransmitters in the transmission of action potentials?
Ap arrives at synaptic knob.Voltage gated Ca2+ channels open.Diffuse into knob. Cause vesicles of ACh to fuse with presyn. membrane, Ach released by exocytosis. Diffuse across cleft. Binds to receptor sites on post syn.membrane.Na channels open=a.p
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What are the roles of synapses in the nervous system?
Convergence=several presynaptic neurones to one neurone. Divergence= 1 to many. Correct direction of transmission. Filter low level signals. Amplify low level signals- summation. Habituation. Memory pathways
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How is the resting potential established and maintained?
Voltage across neurone cell membrane at rest. -60mV, na+/k+ pumps use ATP to pump 3na+ out and 2k+ into cell. Membrane more permeable to k+ so diffuse out. More negative inside due to anions so polarised cell. Resting potential.
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How is the action potential generated?
Gated Na+ ion channels open due to energy changes in environment- Depolarisation. Changes in potential difference across membrane. Threshold reached for depol. to occur up to +40mV. Act.pot transmitted along entire neurone
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How is the action potential transmitted?
Na ion channels open=imbalance so local current created in cytoplasm of neurone(movement of charged particles). Sodium ions, once outside cell, move away from area of increased concentration. Na+ moves along and pd of membrane reduced. ap moves along
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What are the roles of the sensory receptors in mammals?
Convert different forms of energy into nerve impulses. Energy changes eg light intensity detected and converted into impulse
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What is hyperpolarisation?
When the potential difference overshoots slightly after repolarisation
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Card 2

Front

What differences in structure and function are there between myelinated and non myelinated neirones

Back

Myelinated= faster transmission of action potential. Long distance signals, more rapid resonse. NON= shorter distance, body function co ordination eg breathing and digestive system

Card 3

Front

Describe the structure of the cholinergic synapse

Back

Preview of the front of card 3

Card 4

Front

What is the role of neurotransmitters in the transmission of action potentials?

Back

Preview of the front of card 4

Card 5

Front

What are the roles of synapses in the nervous system?

Back

Preview of the front of card 5
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