Physiology - Test 2 study guide
Terms
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- transducers
- converts one kind of stimulation to another
- Conductors
- Transmits info from A to B
- Integrators
- Impulses will be interpreted
- cells found in Nervous System
- Neurons & Glial Cells
- Kinds of neurons
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1. Anaxonic
2. Bi-Polar
3. Unipolar
4. Multipolar - Anaxonic Neuron
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- not well understood
- connecting neurons in the CNS
- no axon - Bi-Polar Neuron
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- 1 axon
- 1 dendrite
- sensory (special senses - taste, vision) - Unipolar Neuron
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- sensory (hot, cold, touch)
- axon a little shorter than dendrite
- Ex. Dorsal Root Ganglion - Multipolar Neuron
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- motor neuron
- connecting neurons
- peripherial nervous system - Types of Glial Cells (Neuroglia)
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Of CNS:
1. Ependymal
2. Astrocytes
3. Microglia
4. Oligodendrocytes
Of PNS:
1. Satellite cells
2. Schwann Cells - 2 glial cells that work together to form BBBarrier
- Ependymal and Astrocytes
- Ependymal cells
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In CNS:
- behave as epithelial
- lines and covers tissues - Astrocytes
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In CNS:
- multi processes
- connective tissue of CNS
- structural support
- work with Ependymal cells for BBB - Microglia cells
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In CNS:
- wandering phagocytes of CNS
- ingest potential pathogens
- clean up debris - Oligodendrocytes
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In CNS:
- myelination of fibers in CNS - Satellite Cells
- In PNS - similar to Epindymal and Astrocytes
- Schwann Cells (aka neurolemmacyte)
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In PNS:
- surround axons in PNS
- myelination in PNS - Nerve
- Bundle of axons and/or dendrites.
- Membrane potential
- Difference in charge between inside and outside of cell.
- All membranes have 3 types of ion channels
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1. leak channels
2. Sodium Potassium Exchange pump
3. Gated - chemical, mechanical, voltage - Leak channels
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- aka passive channels
- always open
- tend to be more permeable to K than Na - 3 forms of gated channels
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- chemically regulated
- voltage-regulated
- mechanically regulated - 3 states of gated channels
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- closed, but capable of opening
- open
- closed, incapable of opening - Sodium Potassium Exchange Pump
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- maintains resting potential at -70mV
- used ATP to pump out Na+ and pump in K+
3 Na to 2 K - What initiates an action potential?
- Opening and closing of gated channels.
- Action Potentials
- Propagated changes in the transmembrane potential that, once initiated, affect an entire excitable membrane.
- Absolute refractory period
- Does not matter how many other stimuli, cannot get another action potential.
- Relative refractory peoriod
- possible to get another action potential generated, but takes greater stimuli
- summation
- addition of stimuli
- temporal summation
-
addition of stimuli occurring in rapid succession.
Occurs at a single synapse - spatial summation
- simultaneous stimuli at different locations have a cumulative effect on the transmembrane potential.
- EPSP creates?
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Excitatory Post synaptic potential
- depolarization (move toward threshhold) - IPSP creates?
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Inhibitory Post Synaptic Potential
- hyperpolarize - move away from threshold. - Saltatory conduction (propagation)
- Action potential "jumps" from node to node rather than moving along the axon in a series of tiny steps.
- 3 types of fibers & describe
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Type A - largest, myelinated, 300 mph
Type B - intermediate, myelinated, 40-45 mph
Type C - smallest, unmyelinated, continuous propagation, 2 mph - 2 forms of synapses
- Electric or Chemical
- Electric synapse
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- rarest
- the pre & post synaptic membranes are locked together at gap junctions
- known advantage - quicker response due to connection at gap junctions. - 2 types of Chemical synapse & describe
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- may or may not propagate the postsynaptic cell - depends on the NT
Cholinergic - synapses that release AcH
Adrenergic - uses a variety of NT - Neuromodulators
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- not necessarily a NT
- alters the rate of release of NT or alters the affect the NT has on the post synaptic membrane.
- can effect pre,post or both at the same time
- can operate on thei own or in conj with NT's. - NM effects
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Direct effect - Ionotropic - causes change in ion concentrations between inside and outside of receptor cells.
Indirect effect - Metabotropic - causes metabolic ahnges of the post synaptic cell. Overall change in the cells metabolism. G-protein GTP enzymes linked to them. - What affects nerve inpulses?
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concentration of Na+, K+, Ca+, Temperature
if conc of Na+ & K+ are to high or low, affect resting potential, if temp high, ion movement faster through leak channels.
H+ in extracellular fluid - effect of depolarizing membrane
Buffers very important in cellular physiology - Types of reflexes
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- learned/acquired - trained response
- somatic - control skeletal muscle contractions
- visceral - autonomic - cardiac muscle
- monosynaptic - one synapse
- polysynaptic - more than one synapse
- cranial - processing in brain
- spinal - processing in the spinal cord - 4 types of neural pathways
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- Linear pathway (serial processing)
- Diverging pathway (one -- to many) comon - motor
- Converging pathway (many -- to one) common - sensory - less convergence
- Reverberating (Linear -- loop) will continue to cycle stimulate until circuit fatigues or run out of NT's - 5 sensory receptors
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1. thermoreceptors (free nerve endings)
2. chemoreceptors (respond to chemical changes)
3. photoreceptors (respond to light)
4. mechanoreceptors (respond to mechanicl stimulus)
5. nociceptors (pain receptors) - break down Mechanoreceptors
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1. baroreceptor - blood pressure
2. tactile receptors - touch receptors
a. tactile disc (merkels discs) free nerve endings with padlike structures.
b. lamellated corpuscle (deep touch - vibratory receptors)
c. organ of ruffini (deep touch - do not adapt quickly) - Site of sharpest vision
- fovea
- Blind spot?
- Optic disc
- Rods
- react to all wave lengths of visible, low intensity light.
- Cones
- respond to certain wavelengths - color vision.
- Organ of Corti
- organ of hearing
- amplitude
- how many hair cels are being stimulated at a given time.
- dynamic equilibrium
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semi circular ducts filled with endolymph
detect rotational movements of the head. - static equilibrium
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Utricle and Saccule
Provide equilibrium sensations, whether the body is moving or is stationary. - incomplete tetany
- muscle fiber contract, begin to relax but restimulated
- complete tetany
- stimulation so close together - no chance to relax. muscle will fatigue.
- treppe
- tension rises in stages - like warming up
- types of muscle contractions
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Isotonic - as muscle contracts - tension remains stable - muscle gets shorter. (to move)
Isometric - as muscle contracts - tension increases - muscle does not change much (maintaining posture) - Kinds of muscle fibers
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1. slow twitch (lg # of mitochondria, high conc of myoglobin, slower to react, slower to fatigue)
2. intermediate (middle # of mitoch & myoglobin,)
3. fast twitch (few mitochondria, myoglobin, anerobic resp, react quick, fatigue rapidly) - Charactics of Cardiac muscle
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- intercallated discs (gap junctions between cells)
- striated, pacemaker cells,
- deep nuclei - 2 subgroups of smooth muscle
- single unit & multi unit