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172 Cards in this Set
- Front
- Back
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What is the afferent branch of the auntonmic nervous system? what does it monitor? |
visceral sensory branch. Visceral sensory receptors monitor internal organs |
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What are the three afferent sensory receptor branches and what do they sense? |
Somatic senosry receptors- postion, touch, pressure, pain, temperature.
Special senosry receptors- 5 senses (smell, vision, taste, hearing, balance.
Visceral sensory receptors- monitors internal organs |
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What are sensory receptors? |
receptors that detect change in the internal and external environment |
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The somatic/special/visceral sensory receptors are classed as the? |
sensory division of the peripheral nervous system |
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afferent pathways of the PNS take information to the? |
CNS- spinal cord and brain |
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Efferent pathways come from what division of the brain? |
Motor division |
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Motor division of the brain carries demands to the? |
Peripheral tissues and systems |
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CNS carries commands to the two PNS motor divisions. What are the two motor divisions? |
Voluntary and involuntary |
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The voluntary and involuntary division are know as... |
Somatic and autononmic nervous systems |
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the somatic nervous system controls? |
skeletal muscle contractions |
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the autonomic nervous system controls... |
automatic regulation of smooth muscle, cardiac muscle, glands and adipose tissue |
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What are the two divisions of the autonomic nervous system? |
sympathetic and parasympathetic nervous system |
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the nervous system consists of? |
CNS and PNS |
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CNS consists of? |
brain and spinal cord |
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PNS consists of? |
all neural tissue outside of the CNS- spinal branches |
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CNS- what are the lobes of the brain... |
Brain-frontal lobe parietal lobe temporal lobe occiptal lobe Brain stem- Midbrain, Pons and medulla Cerebellum |
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The brain can be broken up into three sections, what are they? |
Forebrain Midbrain Hindbrain |
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The Forebrain contains the cortex, what are the two divisions of cortexs, what do they do? |
Somatosensory cortex- takes afferent action potentials Motor cortex- sends efferent action potentials |
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Forebrain structures are... |
The cortex, limbic system Sub-cortical forebrain structures are- thalamus, hypothalamus |
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Thalamus is the... |
pre-corticol relay point for sensory neurons |
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Hypothalamus monitors via what recepetors... |
chemoreceptors thermoreceptors osmoreceptors |
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How does the hypothalamus regulate/control bodily functions |
Afferent/efferent neural connections use autonomic pathways and neurohormones (releasing/inhibiting) to regulate body function |
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White matter is? |
myelinated |
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grey matter is? |
unmyelinated |
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how do neurons enter and leave the cortex? |
via tracts |
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how many synapses are within the cortex? |
10 billion |
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What forms the unmylenated grey matter in the cortex? |
pyramidal neurons |
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what forms the mylenated white matter? |
tracts within the brain containing bundles of axons |
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what is the main regulator of homeostasis? |
hypothalamus |
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5 structures of the forebrain are? |
the cortex sub-cortical forbrain structures are... thalamus hypothalamus amygdala hippocampus |
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Lots of neurons synapse at what structure in the forebrain before they branch out into the brain? |
hypothalamus |
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What is the function of the Amygdala? |
responsible for emotional learning, conditioning to fear, anger and pleasure |
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Two facts about the Amygdala |
1. innervation is bi-directional: neurons are afferent and efferent 2. receives input from the CNS areas, including all sense. |
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Function of the Hippocampus? |
Sorts input and stores it into memories, control memory retention |
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1 fact about hippocampus |
Neurons also bi-directional |
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Where is the mid-brain |
small area above the Pons |
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What is the mid-brain involved with? |
Mood- via dopamine receptors |
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Structures of the hindbrain? |
Pons medulla oblongata cerebellum |
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What is the hindbrain? |
brain stem and cerebellum |
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what structures are within the brain stem and cerebellum |
Pons medulla oblongata cerebellum |
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What are the Pons responsible for |
respiratory centre |
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Four autonomic functions of the medulla? |
resp rate and depth, HR and strength, vasomotor tone digestion |
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the medulla regulates what nervous system |
autonomic |
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Neuclei in the pons connecting the? |
forebrain and cerebellum |
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3 Functions of the cerebellum? |
processing position movement developement of fine motor skills |
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Where do most neuronal pathways cross sides? |
in the Medulla! |
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what effect can the medulla have on the cardiovascular system? |
can determine lume size of vessels= increase BP |
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How many pairs of spinal nerves are there? |
31 pairs |
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Each spinal nerve carries 3 things between the spinal cord and the body |
motor signals sensory signals autonomic signals |
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the 31 pairs of spinal nerves make the ? |
PNS |
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Where does the spinal cord start? |
below the medulla |
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the centre cross of the spinal cord is grey because? |
its full of synapses |
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the outter white of the spinal cord is white because? |
mylenated axons |
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How many tracts does the spinal cord have? |
Four i.e. lateral tract |
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Interneurons can be? |
Inhibitory/excitory |
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interneuron can be? |
stimulatory/inhibitory |
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What can an interneuron inhibit? |
the action potential |
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PNS ganglia are relay points that contain? |
neural cell bodies, usually synapses |
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Collections of associated ganglia are known as? |
Plexuses |
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Dorsal root ganglia contain? |
sensory neuron cell bodies |
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Sympathetic ganglia form the? |
Paravertebral ganglia |
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Parasympathetic ganglia are? |
small and close to organs |
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Structural units??? |
Nerves and neurons |
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The layers of the nerve trunk (outter to inner) ? |
Epineurium- perineurium- endoneurium- myelin sheath- axon (nerve fibre) |
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Endoneuriem are in bundles of? |
Fasicles |
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Multipolar myelinated neuron composed of? |
Dendrite, soma, nucleus, myelin sheath, axon, axon terminal |
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Soma of the cell is? |
the cells body |
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Synapses occur at? |
the axon terminal to dendrite |
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Where is the axon hillock? |
at the start of the axon, between the soma and axon |
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What 3 types of neuron are there? |
Multi-polar interneurons Motor neuron Sensory neuron |
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What neuron has the soma in the middle of the neuron? |
Sensory neuron |
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Motor neurons synapse with? |
muscle |
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What neurons have a myelin sheath? |
Motor and sensory |
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What neurons dont have a myelin sheath? |
Multipolar interneuron |
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What are dermatones? |
where the spinal nerve levels serve the skin |
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Why do we feel shoulder pain when we have cardiac pain? |
because the nerves serving that area come in at the same level |
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All sensory neurons have their cell body where? |
in the dorsal root ganglion |
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Ganglion is? |
Collection of cell bodies in the PNS |
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Lots of ganglia together is a? |
Plexus |
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Do autonomic afferent and efferent fibres travel in the same nerve? |
Yes |
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The nerve trunck contains? |
Fasicles of nerve fibres. Afferent and efferent/ sympathetic and parasympathetic |
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Where does the action potential of a neuron propergate? |
At the Axon hillock |
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Where does the action potential in a neuron generate? |
in the Soma |
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Potential generating in the soma are called? |
Graded potentials |
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Action potentials in the neuron propagate down the? |
axon |
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Where are Pyramidal neurons found? |
brain |
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How many sets of dendrites do Pyramidal neurons have? |
2 |
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Neural supporting cells are? |
Schwann cells Glial cells |
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2 Function of schwann cells? |
envelop all peripheral nerve axons Form myelin sheath in myelinated peripheral nerves |
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Name the Glial cells |
Oligodendrocytes Astrocytes Microglia |
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Function of Oligodendrocyte? |
Myelinate CNS axons |
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Where do you find Astrocytes |
in the CNS |
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5 Functions of Astrocytes |
Control circulation and nutrition, sit at synapses, affect neurtrasnmitters, help seal BBB |
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Function of microglia |
Macrophage equivalent in the brain |
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Types of sensory receptors |
Mechanoreceptors Thermoreceptors Nociceptors Electromagnetic receptors Chemoreceptors |
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mechanoreceptors respond to? |
stretch and pressure |
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thermoreceptors respond to? |
cold/warmth |
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nocireceptors respond to? |
pain |
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Electromagnetic receptors respond to? |
light on the retina |
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chemoreceptors respond to? |
taste, smells, blood gases, glucose, fatty acids, amino acids |
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Modality refers to a sensory receptors... |
receptor being differentialy sensitive |
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Senosry receptors open and close what? and generate what? |
ion channels, generate a graded potential |
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3 Inotropic sensory receptors are? |
mechanoreceptors thermoreceptors electroreceptors |
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2 Metatropic senosry receptors are? |
Chemoreceptors Photoreceptor |
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2 areas of summation are? |
spatial and temporal |
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what does spatial summation mean? |
In one nerve the strength of the impulse depends on the number of neurons stimulated. Or the number of graded potentials on the dendrite |
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What does temporal summation mean? |
the repetiveness/strength of the impulse |
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Monosynaptic means? |
no involvement with the brain |
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Tapping the patella tendon stimulates the what of what muscle? |
muscle spindle in the quadriceps |
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What receptor is in the muscle spindle? |
mechanoreceptor |
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What is the Golgi tendon reflex? |
protective reflex- to drop heavy loads |
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The corticospinal motor pathway controls the? |
Concious voluntary movement of the body |
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the corticospinal pathway isa primary... |
efferent motor pathway |
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is the corticospinal pathway a reflex? |
No- its a concious voluntary movement |
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where does the action potential for the corticospinal motor pathway start? |
in the pyramidal neurons of the primary motor cortex |
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What are the stages of the corticospinal pathway? |
1.Action potential generated in the pyramidal neurons of the motor cortex 2.Descends- brain stem- medulla oblongata 3.Neuron enters tract called pyramids in the medulla 4.base of medulla axons cross (decussation of the pyramids) 5.once crossed to the contralateral side they enter the... opposite lateral corticospinal tract in the white matter of the cord 6. at target level the axons enter the grey matter of the ventral horn of the spinal cord 7. in the ventral horn they synapse with interneurons, or directly with peripheral motor neurons 8. these carry the action potential along spinal nerves to skeletal muscle |
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Why would the same pathway use inhibitory interneurons at the target level? |
some muscles would need to relax so as not to antagonise contracting muscle |
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At the base of the medulla most axons in the pyramids cross, this is called the? |
decussation of the pyramids |
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The autonmic nervous sytem has two devisions they are? |
Parasympathetic and sympathetic |
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Parasympathetic is responsible for? |
Rest and digest |
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the sypathetic nerves are responsible for? |
fight/flight |
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ipsilateral means? |
the same side |
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the sympathetic nervous sytem (SNS) preganglionic neurons are? |
short (they have a short neurone, that synapses with a long neuron) |
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Parasympathetic has ganglia close to the effector organ so its? |
preganglionic neuron is long |
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the sympathetic nervous sytems uses what neurotransitters? |
ACH then Noradrenaline |
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the parasympathetic nervous system uses what neurotransmitter? |
ACH and ACH |
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what nervous system does rest and digest? |
parasympathetic nervous sytem |
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some things the parasympathetic nervous do? |
constrict pupils stimulate salliva slow heart beat constrict airways stimulate stomach activity inhibit release of glucose/stimulate gall bladder stimulate activity of intestines contract bladder promote erection of genitals |
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sympathetic nervous sytems does... |
dilate pupils inhibit salivation increase heart beat relax airways inhibit stomach activity release glucose/inhibit gall bladder inhibit intestines secrete epinephrine and norephinephrine relax bladder promote ejaculation and vaginal contraction |
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what neurotransmitters does the sympathetic nervous system use? |
epinephrine, norephineprine |
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sympathic pathways use |
acetylcholine and norephinephrine |
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parasympathetic pathways use |
Acetylcholine |
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RMP for a neuron is? |
-70mv |
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neural threshold for depolarisation is? |
-50mv |
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neural depolarisation goes to? |
+40mv |
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on neurons voltage-gated channels reach threshold and open at? |
-50mv |
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when the voltage gated channels open...what influxs, and takes voltage to what? |
Na+ influxes and takes the voltage to +40mv |
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at +40mv what closes |
Na+ channels |
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At +40mv when Na+ channels close, what opens? |
K+ channels open- K+ effluxs following its electrochemical gradient |
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at +40mv when Na+ channels close is also called? |
repolarisation |
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Opening K+ channels and K+ effluxing causes |
Hyperpolarisation |
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Why hyperpolarisation |
to stop backward propergation |
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what restores RMP |
NA+/K+ ATPase pump |
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Nerves can contain myelinated and non-myelinated neurons. Whats the difference |
1. myelinated transmits faster 2.Postganglionic SNS neurons are unmyelinated |
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How is an action potential transmitted at a synapse |
chemically by neurotransmitters |
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what do chemical neurotransmitters do at the post synaptic junction |
they bind to specific chemically-gated ion channels |
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in the pre-synaptic cleft chamical neurotransmitters are held in? |
vesicles |
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what influxs to exocytos the neurtransmitters? |
Ca+ influxs- interacts with the cytoskeleton and causes endocytosis of the vesicles |
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Ca++ gates at the pre-synaptic junction/ what type of gate is it? |
voltage-gated Ca++ channels that reach threshold |
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a chemical neurotansmitter can also be called a? |
ligand |
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Inactivation of neurotransmitters |
Serotonin, GABA< noradrenaline are inactivated by re-uptake |
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How is dopamine inactivated |
dopamine diffuses away from the cleft and is excreted |
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how is ACH inactivated? |
ACH is degraded in the synaptic cleft by actylcholinesterase |
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what determines the action of the post-synaptic response, i.e. inhibitory/excitatory |
depends on the action of the post synaptic receptor for a particular neurotransmitter |
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ACH can bind to |
inhibitory and excitatory receptors |
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Excitatory postsynaptic potentials (EPSPs) |
the receptor opens Na+ channels= influx of Na+= depolarisation |
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Inhibitory postsynaptic potentials (IPSPs) |
the receptor opens CI- or K+ channels= influx of CI- or efflux K+= hyperpolarisation |
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GABA is? |
inhibitory |
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How does GABA inhibit an action potential? |
GABA binds to CI- sensitive channels= opens the channels= CI- influx causing hyperpolarisation |
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what does the axon hillock contain? |
a high number of voltage-gated Na+ channels |
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a neuron can receive input from _______ and can be what? |
many different presynaptic neurons and can be IPSPs or EPSPs |
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IPSPs and EPSPs inputs are summated to determine if there will be an??? |
action potential |
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the voltage gated-channels at the axon hillock have a threshold of? |
-55mv (more sensitive) to opening |
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If threshold is reached at the axon hillock the Na+ open then... |
Na+ from the soma and starts a wave of excitation down the axon |
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the axon hillock summates the graded potentials and generates an action potential |
Adjacent voltage-gated Na+ channels to the initial post-synaptic axon open and influx Na+ generating a wave of depolarisation |
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Spatial summation: EPSP contribute to depolarisation within the... |
soma |
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Spatial summation: IPSP contribute to to hyperpolarisation within the... |
soma |
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Temporal summation: Individual synapse receiving repeated IPSPs or EPSPs will repeat the... |
graded potentials |
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in temporal summation why could it create an action potential |
a rapidly firing synapse creating one type of graded potential may counteract multiple slow firing synapses of the opposite type Increase the effect of the EPSP or IPSP because it'll be too fast to restore RMP |
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Predominance of IPSP in soma means? |
Na+ gates stay locked |
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Predominance of EPSP in the soma means? |
threshold reached= axon hillock generate an action potential |
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Spatial summation in the soma could win because? |
multiple graded potentials potentials closer to the axon hillock |
