Term
Other names for______ in muscle:
-Plasma membrane
-Cytoplasm
-Endoplasmic Reticulum |
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Definition
-Sarcolemma
-Sarcoplasm
-Sarcoplasmic Reticulum |
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Term
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Definition
Sarcomere: Z line to Z line
Middle of Sarcomere: M line
A-Band- Dark due to myosin
H-zone- Lighter part of A-band, no overlap
I-band- light due to Actin |
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Definition
Made up of G actin(Globular)
A bunch of G actin makes an F actin which is a double helix |
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Definition
| protein that lies in the groove of the F actin, spans 7 G actin molecules |
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Definition
Contains Ca2+ ATPase: pumps Ca from ICF to reticulum
Calsequestrin binds up to 43 Ca
Ryanodine receptor: Ca release channel |
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Definition
| Extensions of sarcolemma that go all the way through the cell |
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Definition
Contains 2 sarcoplasmic reticulum and 1 T-Tubule
Also has dihydropyridine receptor(voltage receptor that pulls open Ryanodine Receptor) |
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Definition
A motor neuron and all the muscle fibers it innervates.
There can be many(gross muscle movement) or few(fine muscle control. |
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Definition
| Consists of motor neuron end-terminal, synaptic cleft, and motor end plate of muscle cell. |
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Definition
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Definition
Arranged in synaptic folds with concentrated acetylcholine receptors.
-End Plate potential is always excitatory |
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Term
| Muscle depolarization events |
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Definition
| Depolarized T-tubule causes conformational change to dihydropyridine receptor, causes ryanodine receptor to open and release Ca, which initiates sliding filament mechanism. |
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Definition
Only ATP can be used.
Phosphocreatine can give a little
Glycolysis(Anaerobic) provides enough for a 1.3-16 minutes of max muscle usage
Oxidative Metabolism- provides the most for sustained physical activity. |
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Term
| Pathophysiology of Muscle |
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Definition
-Botulinum toxin- messes with Atch, results in paralysis
-Myasthenia gravis-autoimmune, autoantiboies attack Atch receptors
-Muscular Dystrophy- genetic disease, messed up dystrophin, muscles are replaced with fatty fibrous tissue. |
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Term
| Cardiac Muscle Characteristics |
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Definition
| smaller, one nuclei, intercalated disks, dyads w/one T-tubule, |
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Term
| Specialized Cardiac muscle cells |
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Definition
Atrial/Ventricular myocytes
Purkinje fibers- less actin/myosin, larger diameter
SA/AV node |
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Term
| Cardiac Muscle generates 2 types of AP: |
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Definition
Fast Response: A/V myocytes & Purkinje fibers
Slow Resonse: SA/AV node |
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Term
Cardiac Muscle Contraction
-iNa
-iCa
-ito
-iK1
-iK |
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Definition
-iNa-opens briefly and initiates depolarization
-iCa- allows slow influx of Ca
-ito-allows slow efflux of K
-iK1-Generally only open while resting, aids in repolarization
-iK-mainly in charge of repolarization |
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Term
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Definition
Fast Na channels open, depolarizing cell.
iK1 gates close |
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Term
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Definition
Initial repolarization occurs through i-to channels.
These channels don't close until end of P2 |
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Term
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Definition
| Plateau happens due to Ca entering through iCa and K entering through iK and iK. |
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Term
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Definition
| K out overpowers Ca in. iK lets more out, iK1 starts to let more K out. i-to no longer contributes. |
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Term
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Definition
| Na-K and Ca pumps activated. |
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Definition
Not a rapid upstroke.
Upstroke mediated by iCa, Ca blockers can affect |
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Definition
| Mediated by K leaving through iK |
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Term
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Definition
-There is a spontaneous depolarization due to iF.
-Slow depolarization activates iCaT which aids in depolarization. iCaT not blocked by Ca blockers.
-L-type Ca-in charge of depolarization, can be blocked. |
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Term
| Cardiac excitation: dihydropyridine receptor |
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Definition
| activates Ryanodine receptor through chemical no mechanical process like in skeletal muscle |
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Term
| Myocyte contraction directly proportional to: |
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Definition
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Term
| Catecholamine affect on myocytes |
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Definition
increases cAMP, which increases PKA, which phosphorylates iCaL channels. This all allows in more Ca.
-They also increase rate of relaxation by phosphorylating phospholamban, which pumps Ca out faster. |
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Term
| Catecholamine affect on SA node |
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Definition
| funny channels have increased slope of depolarization. |
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Term
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Definition
-Also called Digitalis
-Block Na-K pump. less Na inside cell.
-Slows Ca-Na pump which usually puts Ca out and Na in. |
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Term
| Acetylcholine one heart muscle |
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Definition
-Only decreases atrial mycytes, not ventricular myocytes.
-Decrease formation of cAMP
-Puts more K out, hyperpolarizes and takes longer to reach threshold.
-Also makes funny channels take longer |
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Term
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Definition
-Most have gap junctions(unitary)
-Smaller than skeletal
-No sarcomeres, not striated
-Myosin regulated contraction
-No T-tubules, but have caveoli |
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Term
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Definition
-Twice as much actin that are long and skinny
-Actin originates from dense body
-Dense bodies make up dense bands
-No troponin in smooth muscle |
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Term
| Smooth Muscle Contraction |
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Definition
-Most Ca comes from outside cell
-Ca binds to calmodulin
-Calmodulin activates myosin light chain kinase(MLCK)
-MLCK phosphorylates regulatory myosin light chain.
-Then crossbridges with actin form |
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Term
| Hormone affect on smooth muscle |
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Definition
-Increases DAG and IP3
-IP3 acts on Sarc.Ret to release Ca
-DAG increases PKC which increases contractibility |
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Term
| Smooth muscle innervated by autonomic nervous system |
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Definition
| -Nerves terminate in varicosities, like beads on a string. |
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Term
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Definition
| Possible due to latch mechanism |
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Term
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Definition
| specific type of sensation that can be detected by a sensory receptor |
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Term
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Definition
Electrotonic, graded, not propagated.
Similar to EPSP |
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Term
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Definition
| Involves a receptor, afferent sensory neuron, efferent motor nerve, end organ |
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Term
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Definition
-A monosynaptic reflex
-Sensory receptor is a muscle spindle |
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Term
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Definition
-3-12 narrow muscle fibers
-These are called intrafusal fibers
-Wrapped in primary afferent neurons |
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Term
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Definition
Alpha- neuron that comes from muscle spindle
Gamma-neuron that activates stretch reflex |
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Term
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Definition
-Activated by tension
-activates inhibitory interneurons
-Prevents extreme contraction |
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Term
| Dorsal Column-Medial Lemniscal System |
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Definition
-2 Pt discrimination, vibratio, proprioception
-Large and myelinated
-Crosses between medulla and midbrain
-Needed for localizing pain/temp, not for sensing them. |
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Term
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Definition
-Small diameter
-Crosses in the spinal cord immediately
-Neospinothalamic-fast pain
-Paleospinothalamic-slow pain |
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Term
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Definition
-Descend from the cerebral cortex
-Release enkephalin which inhibits incoming painful stimuli
-Morphine and naloxone are similar drugs |
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Term
Primary cortex
Supplementary cortex |
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Definition
Primary- makes sure that was is suppose to happen happens
Supplementary- organizing and planning a sequence of muscle activation |
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Term
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Definition
Control of rapid muscle movements
-Knows the plan and receives info on what is actually happening to make sure the 2 line up.
-Stops movement when a target is reached
-Necessary for balance |
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Term
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Definition
-Ipsilateral loss of function
-Past pointing- overshooting an object
-Intention tremor-absent at rest
-Ataxi-uncoordinated movements
-Decomp of movement- steps instead of fluid
-Slurred speech- dysarthria |
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Term
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Definition
Direct Pathway- excitatory
Indirect Pathway- inhibits |
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Term
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Definition
-Voluntary tremors due to lack of dopamine
-scarcity of movement
-Treated with L-Dopa |
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Term
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Definition
-Destruction of inhibitory neurons
-Distortion of movement(chorea) |
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