Term
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Definition
1. Automaticity
2. Variable contraction tension
3. Extended contraction time
4. Prevention of wave summation |
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Term
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Definition
Contraction without neural stimulation
-Controlled by pacemaker cells |
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Term
| Variable contraction tension |
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Definition
| controlled by nervous system |
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Term
| Extended Contraction Time |
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Definition
| ten times as long as skeletal muscle |
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Term
| Prevention of Wave Summation and Tetanic Contractions by Cell Membranes - |
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Definition
| due to long refractory period |
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Term
Length-Tension Relationship:
The forcefullness of muscle contraction |
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Definition
| depends on the length of the sarcomeres |
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Term
Length-Tension relationship:
When a muscle fiber is stretched |
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Definition
| there is less overlap between the thick and thin filaments and tension (forefulness) is diminished. |
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Term
Length-Tension relationship:
When a muscle fiber is shortened |
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Definition
| the filaments are compressed and few myosin heads make contact with thin filaments and tension is diminished. |
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Term
| Slow Oxidative Fibers (SO fibers) |
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Definition
-least powerful type of muscle fibers
-APPEAR DARK RED = more myoglobin = stores oxygen in muscle = to make ATP
-Generate ATP mainly by AEROBIC CELLULAR RESPIRATION = USING OXYGEN
-have a SLOW SPEED OF CONTRACTION
-very resistant to fatigue |
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Term
| Fast Oxidative-Glycolytic Fibers (FOG fivers). Glycogen = liver and muscle |
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Definition
-contain LARGE AMOUNTS OF MYOGLOBIN AND MANY BLOOD CAPILLARIES = DARK RED
-generate ATP by AEROBIC CELLULAR RESPIRATION
-moderately high resistance to fatigue
-speed of contraction faster = walking and sprinting |
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Term
| Fast Glycolytic Fibers (FG fibers) |
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Definition
-generate the most powerful contractions
-have LOW MYOGLOBIN CONTENT = LESS OXYGEN STORAGE
-relatively few blood capillaries, few mitochondria = appear white in color
-generate ATP MAINLY BY GLYCOLOSIS = ANAEROBIC
-fibers contract strongly and quickly: fatigue quickly = weight lifting |
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Term
Muscle Metablolism:
MUSCLE FATIGUE |
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Definition
factors that contribute
-INADEQUATE RELEASE OF CALCIUM ions from the SR
-depletion of creatine phosphate
-insufficient oxygen
-depletion of glycogen and other nutrients
-buildup of lacttic acid and ADP.
-Failure of the motor neuron to release enough acetylocholine |
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Term
Muscle Metabolism:
Oxygen Consumption After Exercise |
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Definition
| After exercise, heavy breathing continues and oxygen consumption remain above the resting level. |
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Term
Muscle Metabolism:
Excess post-exercise oxygen consumption (EPOC) = The added oxygen that is taken into the body after exercise = this added oxygen is used to RESTORE MUSCLE CELLS TO THE RESTING LEVEL in three ways.. |
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Definition
1. to convert lactic acid into glycogen
2. to synthesize creatine phosphate and ATP
3. to replace the oxygen removed from myoglobin |
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Term
Control of Muscle Tension:
MOTOR UNITS |
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Definition
-consists of a MOTOR NEURON AND THE MUSCLE FIBERS it stimulates
-the axon of a motor neuron branches out forming NEUROMUSCLAR JUNCTIONS WITH DIFFERENT MUSCLE FIBERS
-total strength of contraction depends on SIZE OF MOTOR UNITS AND THE NUMBER THAT ARE ACTIVATED
-THE INCREASE IN CONTRACTION WITH AN INCREASE IN STIMULATION IS TERMED RECRUITMENT ie see summmation |
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Term
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Definition
| MUSCLE FIBERS IN A MOTOR UNIT IN RESPONSE TO AN ACTION POTENTIAL |
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Term
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Definition
| a BRIEF DELAY BTWN THE STIMULUS AND MUSCULAR CONTRACTION |
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Term
| Contraction Period (10-100 msec) |
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Definition
-Ca++ binds to troponin
-Myosin-binding sites on actin are exposed
-cross-bridges form |
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Term
| Relaxation Period (10-100 msec) |
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Definition
-Ca++ is transported into the SR
-Myosin-binding sites are covered by tropomyosin
-myosin heads detach from actin |
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Term
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Definition
increasing tension or SUMMATION OF TWITCHES
-repeated stimulations BEFORE THE END of relaxation phase |
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Term
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Definition
| sustained but wavering contraction |
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Term
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Definition
| if stimulation frequency is high enough, muscle never begins to relax, and is in CONTINUOUS CONTRACTION |
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Term
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Definition
| skeletal muscle CHANGES LENGTH = resulting in motion |
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Term
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Definition
| skeletal muscle develops tension, but is PREVENTED FROM CHANGING LENGTH |
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Term
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Definition
-STRIATED, FOUND ONLY IN HEART
-single nucleus
-no triads
-are aerobic = HIGH IN MYOGLOBIN, MITOCHONDRIA
-HAVE INTERCALATED DISCKS
-HEART CONTRACTS AS A UNIT
-GAP JUNCTIONS = ALLOW ION PASSAGE |
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Term
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Definition
-specialized contact points between cardiocytes
-join cell membranes of adjacent cardiocytes (gap junctions, desmosomes) |
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Term
| Functions of Intercalated Discs |
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Definition
-maintain structure
-enhance molecular and electrical connections
-CONDUCT ACTION POTENTIALS |
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Term
| Because intercalated discs link HEART CELLS MECHANICALLY, CHEMICALLY AND ELECTRICALLY... |
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Definition
| the heart functions like a SINGLE, FUSED MASS OF CELLS. |
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Term
| SMOOTH MUSCLE IN BODY SYSTEMS |
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Definition
-forms around other tissues
-in blood vessels = REGULATES BLOOD PRESSURE AND FLOW
-in reproductive and glandular systems = PRODUCES MOVEMENTS
-in digestive and urinary systems = forms SPHINCTERS AND PRODUCES CONTRACTIONS
-in integumentary system = ARRECTOR PILI MUSCLES cause "goose bumps" |
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Term
| STRUCTURE OF SMOOTH MUSCLE |
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Definition
| contraction LAST LONGER than skeletal muscle contraction |
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Term
| EPINEPHRINE BOUND TO BETA-ADRENERGIC receptors on smooth muscle cells of the intestines causes them to... |
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Definition
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Term
| EPHINEPHRINE BOUND TO ALPHA2 RECEPTORS causes the arteries to... |
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Definition
| CONTRACT (constrict), REDUCING CIRCULATION TO THESE ORGANS |
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Term
| ACH causes smooth muscle cells in blood vessels to... |
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Definition
| RELAX = INCREASE BLOOD FLOW |
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Term
| ACH acts indirectly by inducing the nearby endothelial cells to make and release NO (NITRIC OXIDE = GAS = ENTERS BY DIFFUSION ["IT CAN GO ANYWHERE IN YOUR BODY"], which then... |
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Definition
| signals the underlying smooth muuscle cells to relax NITROGLYCERINE is converted to NO, which RELAXES BLOOD VESSELS |
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Term
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Definition
| this CYCLIC GMP PHOSPHODIESTERASE (ENZYME THAT BREAKS DOWN CYCLIC GMP). (The cyclic GMP keeps blood vessels relaxed.) |
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