Term
| Accessory proteins link actin filaments to... |
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Definition
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Term
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Definition
-Run through thick filament and attach to Z disk
-Resist overstretching |
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Term
Motor units:
Small for... |
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Definition
| fine control (3-6 muscle fibers per nerve fiber) ex. Eye movement |
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Term
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Definition
-Muscle scars and weakens
-Women can get this but they are typically carriers |
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Term
| Transfer contraction forces to... |
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Definition
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Term
| Most common form of: Muscular Dystrophy? |
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Definition
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Term
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Definition
| Defect in gene that makes dystrophin |
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Term
| Muscular Dystrophy: Sarcolemma and sacromeres move... |
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Definition
independently, tears membrane, degradation of contractile proteins.
(cant prepare muscle cell, it degrades) |
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Term
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Definition
| Strength (1000 muscle fibers per fiber) ex. Gastrocnemius |
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Term
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Definition
| Contains synaptic vesicles with acetylcholine (ACh) |
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Term
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Definition
-Synaptic knob
-Synaptic cleft
-Synaptic vesicles
-Basal Lamina |
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Term
Neuromuscular Junction:
Schwann Cell |
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Definition
| Envelops and isolates junction from surrounding tissue fluid |
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Term
Neuromuscular Junction:
Synaptic Vesicles... |
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Definition
| undergo exocytosis releasing ACh into synaptic cleft |
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Term
Neuromuscular Junction:
ACh receptors in... |
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Definition
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Term
Neuromuscular Junction:
Basal Lamina |
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Definition
| Contains acetycholinestrase (AChE) that breaks down ACh |
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Term
Electrical Excitable Cells:
Recall |
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Definition
| Applies to nerve and muscle cells |
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Term
Electrical Excitable Cells:
Unstimulated (resting) cell |
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Definition
-Plasma membrane is electrically charged
-Excess Na+ outside
-Excess K+ inside |
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Term
| Resting membrane potential (RMP) |
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Definition
-Approx. -90mV
-Maintained by Na+/K+ pumps constantly operating (3 Na+ out, and 2 K+ in)
-Compensates for ion channel 'leakage,' gates opening |
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Term
Muscle contraction and relaxation:
Phases: |
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Definition
-Excitation
-Excitation-contraction coupling
-Contraction
-Relaxation |
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Term
Muscle contraction and relaxation:
Recall 2 types of channels (gates) |
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Definition
1. Ligand regulated
2. Voltage regulated |
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Term
| Excitation (Steps 1 and 2) |
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Definition
Nerve signal opens voltage-gated calcium channels in synaptic knob
-ACh releases into synaptic cleft |
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Term
| Excitation (steps 3 and 4) |
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Definition
| -Two ACh molecules bind to each receptor protein, opening Na+ and K+ channels. |
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Term
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Definition
| Opening of voltage-regulated ion gates; creation of action potentials |
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Term
| Excitation-contraction coupling (Steps 6 and 7) |
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Definition
-Action potential spreads down into T tubules
-Opens voltage-gated ion channels in T tubules and Ca +2 channels in SR
-Ca+2 enters the cytosol |
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Term
| Excitation-contraction coupling (steps 8 and 9) |
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Definition
| Calcium binds to troponin of thin filaments |
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Term
| Contraction (Steps 10 and 11) |
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Definition
| -Myonsin ATPase in myosin head hydrolyzes ATP |
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Term
| Contraction (Steps 12 and 13) |
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Definition
-Myosin head releases ADP and Pi, pulls thin filament past thick (power stroke)
-Myosin binds more ATP, releases actin, process repeats |
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Term
| Relaxation (steps 14 and 15) |
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Definition
-Nerve stimulation and ACh release stops
-AChE breaks down ACh |
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Term
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Definition
-Ca+2 pumped back into SR for storage
-ATP required for muscle relaxation also |
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Term
| Rigor Mortis (definition) |
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Definition
| Tightening of muscles when you die |
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Term
Rigor Mortis:
It is the hardening of muscles...hours post death. |
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Definition
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Term
Rigor Mortis:
Muscle contraction but cannot... |
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Definition
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Term
| Muscle relaxation requires ATP, however it is not produced after... |
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Definition
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Term
| Rigor mortis peaks at about...hours after death |
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Definition
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Term
| Rigor mortis peaks about 12 hours after death, then diminishes over the next __ to ___ hours. |
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Definition
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Term
| What decays during rigor mortis (after death)? |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Ig's to ACh receptros of motor end plates |
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Term
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Definition
| Location, cell shape, striations, nuclei, connective tissues, T tubule, nervous stimuation |
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Term
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Definition
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Term
Smooth muscle:
single unit |
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Definition
| Typically two or more muscle layers |
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Term
Smooth muscle:
Examples of single unit |
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Definition
| ex. intestines, most blood vessels, visceral muscle layers (respiratory, digestive, reproductive, and urinary) |
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Term
Stimulation examples:
Involuntary |
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Definition
| Responds to chemical stimulus such as hormones, high CO2, low pH, low O2, or stretch (GI tract) |
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Term
Stimulation examples:
Autonomic nervous system |
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Definition
| ACh or norepinephrine (relax or contract) |
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Term
Stimulation examples:
Single unit |
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Definition
| Neurotransmitter released at varicosities, multiple cells affected |
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Term
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Definition
| Stimuli opens Ca+2 gates, Ca+2 enters cell |
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Term
Contraction:
Myosin binds to.. |
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Definition
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Term
Contraction:
Fatigue resistance requires...ATP |
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Definition
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Term
Contraction:
Ca+2 binds to... (not troponin) |
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Definition
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