Term
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Definition
-striated muscle, (contains dark bands)
-40-50% of body weight
-many nuclei per cell
-voluntary muscle
-attaches to bone |
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Term
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Definition
-visceral muscle
-one nucleus per cell
-involuntary
-makes the walls of the digestive tract, iris of the eye |
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Term
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Definition
-heart
-striations present, but one nucleus per cell
-involuntary |
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Term
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Definition
-sub-unit of muscle cells
-contains contractile proteins which cause the muscle to move |
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Term
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Definition
-sub-unit of the myofibril
-the basic unit of muscle contraction
-know structure (myosin, actin, h-zone, z-line, a-band, i-band) |
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Term
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Definition
-contractile protein, thick filament (strand)
-contains extensions called cross bridges which pull the thin (actin) filaments together when a muscle contracts |
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Term
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Definition
-contractile protein, thin filament
-pulled together when a muscle contraction occurs |
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Term
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Definition
-the area between the actin filaments when a muscle is at rest
-reduces when the muscle contracts |
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Term
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Definition
| -the outer borders of the sarcomere |
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Term
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Definition
| -(dark band), contains myosin & actin filaments |
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Term
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Definition
| -(light band), contains actin filaments only |
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Term
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Definition
| -regulatory protein that blocks myosin binding sites in the actin |
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Term
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Definition
-regulatory protein that positions the tropomyosin
-when calcium ions bond with troponin, it changes the shape of the tropomyosin |
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Term
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Definition
| -actin and myosin do not change their length, but do change their degree of overlap |
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Term
| Steps for Muscle Contraction |
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Definition
1.) an impulse moves down a nerve cell and through the motor neuron
2.) the motor neuron stimulates the sarcolemma, causing it to release calcium
3.) calcium floods into the sarcomere and binds to the troponin complex. this exposes the myosin binding sites on the actin
4.) ATP on the myosin head hydrolyzes. the energy is then transferred to the myosin and changes the shape of the molecule. the myosin cross bridge connects to the actin
5.) cross bridges pull the actin filaments together, eliminating the H-zone |
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Term
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Definition
| -cell membrane of a muscle cell |
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Term
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Definition
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Term
| Muscles need _____, _____, and ______ to function normally |
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Definition
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Term
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Definition
| -molecule that directly supplies energy for muscle contractions |
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Term
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Definition
-glucose breakdown using oxygen
-recharges 38 ATP molecules
-(e.g. quiet, normal respiration)
-(physical activity does not exceed maximum ATP production) |
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Term
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Definition
-glucose breakdown w/o oxygen
-recharges only 2 ATP molecules
-(e.g. phyiscal stress)
-when muscles need more ATP than the mitochondria can normally produce
-lactic acid is produced (causes fatigue) |
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Term
| 2 Types of Muscle Contraction |
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Definition
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Term
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Definition
-produces no movement
-(e.g. pushing against a wall, maintaining posture) |
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Term
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Definition
-produces movement
-sit-ups, push-ups, curls, etc) |
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Term
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Definition
-an increase in muscle size
-due to normal growth, exercise, steroids
-accompanied by an increase in blood flow
-strength training increases total muscle mass, not number of muscle fibers |
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Term
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Definition
-a decrease in muscle size
-due to nonuse, aging |
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Term
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Definition
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Term
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Definition
| -from overexertion or trauma |
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Term
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Definition
-muscle pain
-possibly from strain, flu |
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Term
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Definition
| -overstretching or tearing of muscle fibers (includes tendinitis) |
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Term
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Definition
| -tendinitis of the patellar tendon |
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Term
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Definition
-painful muscle spasms
-may be due to water or ion imbalance |
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Term
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Definition
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Term
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Definition
-muscular weakness/deterioration
-cause of death: paralyisis of respiratory muscle, by 21 yrs of age |
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Term
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Definition
-viral
-muscle degeneration and paralysis |
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Term
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Definition
-benign muscle tumor
-common on the uterus |
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Term
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Definition
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Term
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Definition
-bacterial
-may cause lockjaw, severe body rigidity |
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Term
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Definition
| -decreases angle of the joint |
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Term
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Definition
| -increases angle of the joint |
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Term
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Definition
| -move away from the midline |
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Definition
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Definition
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Definition
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Definition
| -fixed end of muscle attachement |
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Term
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Definition
| -point of attachment to the bone which is moved |
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Term
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Definition
| -surrounds the skeletal muscle |
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Term
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Definition
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Term
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Definition
| -surrounds the entire muscle |
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Term
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Definition
| -surrounds muscle fiber bundles |
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Term
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Definition
| -surrounds individual muscle fibers |
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