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Soma
The Cell Body. Contains nucleus and most organelles
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Dendrites
These are the long slender threads that protrude from the soma. This is the reception area for incoming information from the Axon Terminals of another neuron.
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Axon
The long fiber that extends from the base of the soma to transmit electrical impulses called action potentials.
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Axon Terminals
These are the alien fingers (with pods) that branch off of the Axon. They release neurotransmitters to the dendrites of the next neuron.
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Synapse
These are these are the pods at the end of the Axon Terminals where the exchange of neurotransmitters happens. This is the site of communication between the presynaptic neuron to the postsynaptic neuron and an effector organ
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Leak Channels
- ~Always Open
- ~Potassium only
- ~Located throughout a neuron
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Ligand-gated channels
~Open or close in response to ligand binding
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Resting Membrane Potential
- -70 mV ~When the neruron is at rest.
- ~The inside of the neuron is negative inside
- and the outside is more positive.
- ~K+ can cross through the membrane easily.
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Voltage gated channels:
Open or close in a response to change in the membrane potential.
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Afferent Neuron
- ~Sensory/Visceral receptors
- ~temp and pressure
- ~PNS to CNS
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Efferent Neurons
- ~Effector Organs
- ~CNS to PNS
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Oligodendrocytes
- ~Fat dense cells which form meylination for
- multiple axons and provide protection.
- ~form segments of myelin sheaths of numerous
- neurons at once.
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Schwann Cells
- ~PNS
- One schwann cell forms ONE myelin sheath that myelinates one section of an axon. Seperated by the Node of Ranvier
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Resting Membrane Potential
Determines the equalibrium of potentials for sodium and potass
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Determining Resting Membrane Potential
- 1. Ion concentration gradients
- 2. Membrane permeability
- 3. Ion Channels
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Potassium Equalibrium Potential
- ~As potassium diffuses outof the cell the
- inside of the cell becomes more negative.
- ~Eletrical driving force "pulls" potassium into
- the cell until equalibrium equals -94 mV.
- ~These driving forces are opposite in direction
- and equal in magnitude.
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Sodium Equalibrium
- ~As sodium diffuses into the cell the inside becomes less negative (positive).
- ~eletrical driving force "Push" sodium outside of the cell.
- ~Equalibrium is +60mV
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Resting membrane potential of neurons is permeable to both sodium and potassium however, it is 25% more permeable to ______?
Potassium
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At resting membrane potential, the iside of the cell has more...
potassium and organic anions
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At resting membrane potential, the outside of the cell has more...
Sodium and Chloride
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Sodium going into the cell creates a more______ charge
Positive
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Potassium moving outside the cell creates a more ___________ charge.
Negative
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What is Absolute Refractory Period
the period immediately following the firing of a nuron when it cannot be stimulated no matter how great a stimulus is applied.
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Hyperpolorization
- The time when an action potential is below
- -70mV
a change in a cell's membrane potential that makes it more negative
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Refractory Period
the amount of time it takes for an excitable membrane to be ready for a second stimulus
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Repolarization
The return to resting membrane potential
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Depolarization
a change in a cell's membrane potential, making it more positive
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Threshold
the point at which sodium ions start to move into the cell (instead of out of the cell) to bring about the membrane depoloarization
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Effector organ
Muscle or gland
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eletrical synapse
two neurons linked together by gap junctions finctions in nervous system
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chemical synapse
- most of sensations and motor signals are carried via chemical synapse.
- Neuron to Neuron or Neuron to Muscle
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Synaptic Cleff
where synapse occours.
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axodendritic
From axon to presynaptic neuron
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axosymatic
synapse to soma
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axoaxonic
presynaptic synapses to axon of post synaptic neuron
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presynaptic
Delivering signal
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postsynaptic
Receiviving signal
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post synaptic potentials
a change in the charge on the membrane of the post synaptic cell
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what are the two types of post synaptic potential?
Excitatory and inhibatory
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excitatory post synaptic potential
makes the cell more likely to depolarize. They Hypopolarize to less negative.
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inhibatory post synaptic signals
less likely to produce a potential. hypopolarzation (more negative).
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divergence
one nuron to multiple
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convergence
multiple nurons signal to one nuron
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Grand Postsybnaptic Potential GPSP
- addition of all effects of the ISP & ESP
- the sum of all their signals on one cell
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what are the 2 types of sumation?
Temporal and Spatial
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Temporal Sumation
one synapse fires rapidly onto the next nuron
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Spatial Summation
lots of different synapses occouring all at the same time and in close proximity
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graded potential
a potential that does not reach threshold
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action potential
does not increase
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Brain Lateralization:
Sensory pathways
Motor Pathways
- Rignt Brain controls Left side of body
- Left Brian controls Right side of body
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Right Brain
- Creativity
- Spatial Perception
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Reflexes come from the ___ nerous system?
Central (CNS)
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sensory receptors are what kind of neuron?
afferent neuron
-
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intergration center
interneuron
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effector organ
skeletal muscle
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WHAT ARE THE STEPS OF AN ACTION POTENTIAL
SIGNAL-SODIUM RELEASE-AFFERENT NURON-CNS-EFFERENT NEURON-EFFECTOR ORGAN-RESPONSE
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VOLUNTARY MOTOR CONTROL
- skeletal muscle:
- one motor nuron to a single muscle cell.
- ALWAYS EXCITATORY
- ALWAYS CALLED LOWER MOTOR NEURON
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HOW DO YOU CONTRACT A MOTOR CELL?
ACTIVATE THE MOTOR NEURON
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HOW DO YOU RELAX A MUSLE CELL
DO NOT ACTIVATE A MOTOR NEURON
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SKIN RECEPTORS DETECT:
TEMP AND PRESSURE
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PROPRIOCEPTORS RECEPTORS
DETERMINE ONE FINGER TOUGH AND TWO FINGER TOUCH. SENSE RELATION OF BODY WITH OBJECTS. EX. WALKING AT NIGHT DOWN STAIRS.
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Diseases that Effect the Nervous system
Huntingtons: blocks ability to coordinate motor movement. lots of involuntary movement.
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parkinsons disease
- lack of dopamine in substantia Nigra
- involuntary movement
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autonomioc system
both divisions (parasympathetic and sympathetic) innervate most effector organs.
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what are the 2 divisions of the AUTONOMIC NERVOUS SYSTEM?
- parasympathetic: rest and digest
- sympathetic: fight or flight
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what is the main function of the AUTONOMIC NERVOUS SYSTEM
To regulate and maintain homeostasis
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preganglionic neuron:
the preganglionic neurons are short and called 'cholinergic neurons'.
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postganglionic neurons
postganglionic ones are long ending and embedded in the receptor sites and called 'adrenergic neurons'.
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what are the effector organs under the AUTONOMIC NERVOUS SYSTEM
- cardiac
- smooth muscle
- glands
- adapose tissue
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Presympathetic Nervous system
short pregang. and long postgang.
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parasympathetic nervous system
long pregang and short postgang
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adrenal glands are located----
above the kidneys
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parasympathetic nerves
cranial nerves x Vagus nerves controls what happens in viceral organs.
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efferent fibers are part of the ------ nervous system
autonomic
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afferent fibers transmit info from ------ receptors to the ----
viceral, CNS
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colinergic releases ___
ACH
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adronergic releases_______or______
Epinepherine or norepinepherine
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Where is Beta 1 located?
Cardiac only
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-
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beta 2 and alpha 1 can be found in?
- smooth muscles
- glands
- adapose tissue (fat)
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What adronergice receptor would you find on the smooth muscle surrounding blood vessels going or "feeding" skeletal muscles?
Beta 2
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What adronergice receptor would you find on the stomach?
Beta 2
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What adronergice receptor would you find on the smooth muscle surrounding blood vessels going to the viseral organs?
Alpha 1
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What adronergice receptor would you find on the smooth muscle surrounding your bronchials?
Beta 2
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musclenritic receptors are ______ receptors found on receptor organs
cholinergic
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nicotinic receptors are excitatory receptors that are found
motor nuron, skeletal, muscle
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what are 5 proteins that you need to know about
- sodium potassium pump that pumps sodium out
- voltage gated channels
- potassium out
- sodium in
- leak chanels sodium in potassium out
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refactory period
reagions where we can not open sodium channels. once it is open you cant have another action potential again.
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absolute refactory period:
no action potential
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relative refactory period:
can have another action potential but it will require more stimulius
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