Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
What is a myograph?
|
The graphic recording of contractile therapy. Shows the hill with 1)latent period, lag time, 1-2ms. 2) period of contraction 25 ms and 3) period of relaxation
|
|
|
What does the latent period include?
|
First few ms following stimulation when exctation-contraction coupling is occuring. During this period musc. tension is beg. to increase but no response is seen on the myogram.
|
|
|
How many neurons are in a nerve?
|
100's to 1000's
|
|
|
What is a motor unit?
|
A motor unit consists of a motor neuron and all the fibers it innervates.
A motor nerve has hundreds of motor neurons. |
|
|
What is a muscle twitch?
|
The response to action potential of the motor unit's neuron.
|
|
|
What is the period of contraction include?
|
When myosin heads bind, heads walk, filaments slide, muscle shortens, it's the peak on graph, lasts 25ms.
|
|
|
What is involved in the period of relaxation?:
|
Initiated by reentry of Ca+ back into the SR, heads are feed, fibers slide back.
|
|
|
How long are the latent periods and contraction periods in muscles?
|
latent periods R same in all muscls, while contraction periods vary for different muscles. The eye contraction is quick, soleus is slow twitch.
|
|
|
Why do different muscles contract at different rates?
|
Because of different enzymes
|
|
|
What is the reason behind the smoothness of normal muscle contractions?
|
Graded Muscle Responses
|
|
|
What is Treppe and what does it involve?
|
Called"staircase effect".Show intitial contract. may only be 1/2 as strong as those that occur later due to increasing availability of Ca+2. Treppe theory is one reason athletes do muscle-warm-up. for optimum contract. Seen during intial phase of muscle contraction.
|
|
|
What are the 3 reasons it is good to do muscle warm-up?
|
Treppe (calcium theory), enzyme efficiency, and warm synovial fluid.
|
|
|
What are key points of treppe?
|
seen in initial phase,
increasing calcium, all stimuli are equal strength muscle can completely relax,(comes back to baseline everytime) |
|
|
What does stimulation frequency have to do with graded muscle response (gradually changing)?
|
Stimulation frequency is increasing firing rate of motor neurons & firing a muscle during its relaxation period,never returns to baseline, forced into voluntary tetanus, has to happen after repolarization, but before relax, wave summation is a smooth transition.
|
|
|
What does Charge stimulation strength have to do with Graded Muscle Respone?
|
Also called Multiple Motor unit summation, or recruitment. Action potential voltage is always the same, but more recruited motor neurons add a total higher voltage summation strength.
|
|
|
What is the point called when there is threshold stimulus, and what is maximal stimulus?
|
The point at which contraction is actually observable, the max point of contractile force that plateaus because max. motor units are being used.
|
|
|
What is asynchrones?
|
Not all at once, neurons take turns firing muscle fibers, they take turns with each other, some are contracted,while others are relaxed.
|
|
|
What is muscle tone?
|
Muscle tone is a state in which muscle is in sustained partial contraction; small number of motor units are constantly firing/relaxing. asynchronously: stabilizing joints, posture...
|
|
|
What are the 2 types of muscle contraction?
|
Isotonic contraction and Isometric contraction
|
|
|
What are isotonic muscle contractions
|
Muscle length changes and moves load. 2 different kinds of isotonic: concentric: muscle shortens, does work-pickup ball; eccentric: muscle lengthens & load is moved, generates force, climbing a hill or counters gravity, squats aka muscle breaking.
|
|
|
What do astronauts lack?
|
Gravity which helps with eccentric contraction and with Calcium deposition.
|
|
|
What are isometric contractions?
|
There is no charge in muscle length, because the load is more than the force applied. Muscle filaments don't slide, heads attached, but don't move, but ATP is used. Like pusing against a wall.
|
|
|
What is muscle metabolism and its cycle.
|
Muscle metabolism is all about providing energy for a muscle contraction. Normal ATP output from glyco>kreb>electransport chain>=38 atp, but when no O2 present pyruvic makes lactic acid and only a few AtP-called anaerobic, another way to get atp is phosphorylation of Creatine phosphate.
|
|
|
Two thing muscles provide in muscle metabolism that is unique?
|
Myoglobin stores extra oxygen and Creatine phosphate is hydrolized to give inorganic phosphate to adp to make ATP
|
|
|
What is aerobic respiration?
|
Occurs in the mitochondria, requires oxygen, involves sequence of chemical reactions resulting in 38 Atp
|
|
|
Why isn't hemoglobin sufficient in O2 supply?
|
Muscle swell, compresses blood vessel that supply O2. Myoglobin can supply O2 to prevent anaerobic threshold.
|
|
|
What is aerobic endurance?
|
the length of time a muscle can continue to contract using aerobic pathways.
|
|
|
What is anaerobic threshold?
|
The point at which muscle metabolism converts to anaerobic glycolysis (lactic acid).
|
|
|
What is the process of muscle fatigue?
|
1)vig.muscle contraction,2)O2debt 3) pyruvic acid >lactic acid:anerobic threshold>H+ions pH change>loss of enzyme function>potassium lossK+>impaired Na+K+ pumps>impaired action potential>impaired muscle contraction
|
|
|
What carries oxygen and restores oxygen stores to creatine phosphate after exercise.
|
Myoglobin
|
|
|
Why do myosin heads become stuck during rigormortis?
|
No more ATP available or made
|
|
|
What makes rigormortis start to decline after 12 hr max?
|
The break down of actin and myosin molecules. Eventually detatch, slide back and relax rigor dissipates for the next for up to 48-68 hours.
|
|
|
When does the body start to stiffen?
|
3-4 hours after death
|
|
|
How do you tell if body is past 12 max peak rigor period?
|
The smell given off by bacteria degrading tissues.
|
|
|
What causes extreme contraction during rigomortis?
|
The release of all calcium.
|
|
|
Precise motions require a few or a lot of muscle fibers?
|
A few
|
