Term
| what is the charge on the inside of a cell vs. outside? |
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Definition
| the charge on the inside is Positive (+) and the outside is Negative(-) |
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Term
| what are the cations in high concentration inside of the cell? |
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Definition
|
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Term
| what are the cations in high concentration on the outside of the cell? |
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Definition
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Term
| what are the anions in high concentration inside the cells? |
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Definition
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Term
what are the anions in high concentration outside the cells?
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Definition
| Chloride (Cl-) & Sodium (Na-) |
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Term
| what is a sodium Potassium pump? what does it do? |
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Definition
| active transport pump in Plasma membrane. it transports sodium ions out and Potassium ions in. |
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Term
what is the permeability of the membrane to Na+?
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Definition
|
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Term
| what is the permeability of the membrane to K+? |
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Definition
| Membrane is readily permeable |
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Term
| what are the 2 types of ion channels in the cell membrane? |
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Definition
ungated-open all the time
gated-open or close in response to stimulus. |
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Term
| what are the types of gates and what is their position? |
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Definition
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Term
| what are the types of Na+ gates and what is their position during RMP? |
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Definition
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Term
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Definition
MP becomes more positive
*Na+ ions into cells |
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Term
what is hyperpolarization?
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Definition
MP becomes more negative
*increase K+ or Cl- permeability |
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Term
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Definition
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Term
what is an Action Potential?
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Definition
| sequence of rapid Depolarization & repolarization due to opening of voltage gated ion channels |
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Term
| what happens during the Depolarization phase of AP? |
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Definition
| Na+ Voltage gated ion channels open quickly & Na+ diffuses in --> Depolarization |
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Term
what happens during the repolarization Phase?
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Definition
K+ voltage gated ion channels open more slowly.
-more permeable to K+ than at rest
-->K+ Diffuses out --> Repolarization |
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Term
what is an after potiental? and why does it occur?
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Definition
| K+ gates close slow so the increase in k+ permeability lasts longer than the time needed to return to rmp. --> Hyperpolarization. |
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Term
what role does a Na+/K+ pump play in Ap?
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Definition
| it actively transports (3) Na+ out and (2) K+ in |
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Term
what is the all or none response?
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Definition
| if it responds at all, it will respond completely. |
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Term
what are the 2 phases of the refractory period?
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Definition
1. Absolute- absolutely insensitive to stimulus.
2. Relative-only a stronger than normal stimulus can depolarize. |
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Term
| why does propagation of an ap occur? |
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Definition
| because the neuron is stimulated at the dendrites, and AP is generated at axon hillock. |
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Term
| how is the speed of propagation affected by the type of fiber? |
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Definition
Larger in Diameter- smaller
nerve-muscles
mylein- unmyleinated neurons |
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Term
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Definition
| functional junction between 2 neurons |
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Term
|
Definition
1. Electrical- gap junctions conduct ions directly from cell to cell (uncommon)
2. Chemical- Most synapses |
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Term
Describe the structure of a chemical synapse.
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Definition
Synaptic Cleft-tiny gap between pre and post cells.
Synaptic Knob/terminal-rounded end on the presynaptic axon.
Synaptic Vesicles-small sacs in synaptic knob which store neurotransmitters |
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Term
| what are the events of synaptic transmission? |
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Definition
*AP arrives at axon.
*depolarization of terminal increases permeability of Ca+ in membrane
*Synaptic vesicles fuse to membrane
*release of neurotransmitters
*Neurotransmitters diffuse
*Neurotransmitters binds to specific receptor proteins
*Binding causes graded potentials by opening chemically gated channels.
*NTM is removed from cleft and allows membrane to return to RMP. |
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Term
| what 2 ways can summation of graded potentials occur |
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Definition
Spatial- many presynaptic fibers coverage on 1 pastsynaptic
Temporal- rapid successive stimuli |
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Term
| what are the types of muscle? |
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Definition
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Term
which types of muscles are straiated?
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Definition
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Term
| which muscles are involuntary? |
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Definition
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Term
what are the functions of skeletal muscles?
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Definition
Motion
Heat Production
Posture/Body Support
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Term
| what are the characterictics of a muscle |
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Definition
irritability/exciteability
contractability
extensibility
elasticity |
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Term
| how are muscle fibers bound together to make a whole skeletal muscle. |
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Definition
each muscle fiber is bound by CT with others to form bundles.
Endomysium
Perimysium
Epimysium |
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Term
| describe the layers of the CT |
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Definition
*Endomysium- CT covers/binds individual fibers.
*Perimysium-binds groups into fasciculi.
*Epimysium-covers entire muscle.
*Fascia-CT between seperate muscles
*Tendons-binds muscles to bone. |
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Term
Describe blood and nerve supply to skeletal muscle.
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Definition
Blood- high metabolic activity requires extensive vascularity.
Nerves-skeletal muscle fibers can NOT contract unless stimulated by a nerve. |
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Term
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Definition
| the basic contractile/subunit of skeletal muscle |
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Term
| describe the structure of a sarcomere. |
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Definition
IBands-only thin filaments(light Bands) include Z lines.
ABands-thicnk filaments-myosin(dark bands)
HZone-myosin only, where actin doesnt overlap in A band.
Zlines- dark lines in I band, forms edges of sarcomere.
MLines- within H bands Thickening of myosin filament.
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Term
| describe the structure of thick and thin filaments |
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Definition
Myosin(thick)
*structure is like golf club.
*globular head contain bonding sites for ATP/ATOase & actin.
Actin(thin)
*Kidney bean shaped molecules to form helical strand.
*contain active sites for myosin binding.
Tropomyosin(thin)
*rod-shaped protein fills groove between strands.
*covers active site & prevents attatchment at rest.
Troponin(thin)
*attached at tropomyosin
*can attach to Ca++
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Term
| what is the sliding filament theroy? |
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Definition
when muscle contracts, decreases length.
fibers shorten by shortening myofibrils.
myofibrils shorten as a result from shortening sarcomere. |
|
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Term
| what events take place when a sarcomere shortens? |
|
Definition
*distance from Z-line shortens.
*H-band shortens(may disappear)
*I-Band shortens
*A-band does not shorten, appear close together. |
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Term
| what types of ion channels are involved in producing local/graded potentials? |
|
Definition
|
|
Term
what is the role of Ca++ in muscle contraction?
|
|
Definition
| It exposes active site by binding to troponin |
|
|
Term
| what 3 steps of muscle contraction require ATP? |
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Definition
| Powerstroke, detatchment from actin, and active transport of Ca++ |
|
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Term
| what factors effect muscle contraction? |
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Definition
Thickness of each muscle fiber.
muscle architecture.
initial length of muscle at rest, to short or to long.
number of muscle fibers. |
|
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Term
| what is isotonic contraction? |
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Definition
| tension is constant while muscle changes length |
|
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Term
| what is isometric contraction? |
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Definition
| length of muscle is constant tension increases |
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Term
| how does the all or none principal apply to the contraction of skeletal muscle fiber? |
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Definition
| muscle fiber contracts completely or not at all. |
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|
Term
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Definition
| fiber contracts adn relaxes quiclky to a single stimulus. |
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Term
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Definition
| time between stimulus and contraction. |
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Term
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Definition
| smooth sustained contraction (no relaxation) |
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Term
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Definition
| increase in contraction strength after 1st twitch in a rested muscle. |
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Term
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Definition
| even when a muscle appears relaxed continuous stimuli from the NS keeps muscle in sustained partial contraction. |
|
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Term
| what is the series elastic component of a muscle? |
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Definition
| CT that must be pulled tight before muscle will shorten. |
|
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Term
| what energy sources does Skeletal Muscle rely upon at rest? |
|
Definition
Fatty Acids, Glycogen& glucose, Creatine Phosphate,
& Myoglobin. |
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Term
|
Definition
| the inability of a muscle to maintain its strength of contraction or tension. |
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Term
|
Definition
| the amount of oxygen required to metabolize lactic acid from anaerobic respiration. |
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Term
| define the different types of skeletal muscle fibers. |
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Definition
1. Slow Twitch-(red) Long slow twitch, resist fatigue.
2.Fast Twitch(white) Short fast twitch, easily fatigued. |
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Term
how does smooth muscle differ structurally form skeletal?
|
|
Definition
smooth is smaller spindle shaped fibers. arranged in sheets. no straitions.
lacks well developed, sarcomeres, SR and t tubules. |
|
|
Term
| how does contraction of smooth differ from skeletal |
|
Definition
| smooth is slower and longer in duration than skeletal. |
|
|
Term
| what factors cause smooth muscle contraction? |
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Definition
| Ca++ binds to Calmodulin, Ca++ ATP pumps are slower, requires less ATP. |
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