why do you think the details of skeletal muscle and cardiac muscle contraction....?
931657
Cardiac and skeletal muscles are both highly organized and contract in a single direction, uniformly. Smooth muscle, on the other hand is much more loosely organized. This probably leads to confusion about the order of contraction, etc.
1157941
The contraction of a skeletal muscle is caused by the movement of actin and myosin fibers resulting from influx of exracelluar calcium caused by surface depolarization of the cell initiated by presynaptic discharge of a motor neuron. If this is a homework question, I suppose a one word answer would depend on the nature of the course discussion to which this question is addressed.
971960
Yeah, more mitochondria for energy and more ribosomes (rough ER) to produce proteins necessary for contraction (actin + myosin).\n\nRegards,\nRyan
372330
For most muscles, contraction occurs as a result of conscious effort originating in the brain. The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates the muscle fiber. However, some muscles (such as the heart) do not contract as a result of conscious effort. These are said to be autonomic. Also, it is not always necessary for the signals to originate from the brain. Some reflexes are fast, unconscious muscular reactions that occur due to unexpected physical stimuli. Other actions such as locomotion, breathing, chewing have a reflex aspect to them; the brain will start the contractions, but continuation of the movements can become reflexive. The action potentials for reflexes to unexpected stimuli originate in the spinal cord instead of the brain.\nThere are three general types of muscle contractions: skeletal muscle contractions, heart muscle contractions, and smooth muscle contractions.\nFor skeletal muscles, the force exerted by the muscle is controlled by varying the frequency at which action potentials are sent to muscle fibers. Action potentials do not arrive at muscles synchronously, and during a contraction some fraction of the fibers in the muscle will be firing at any given time. Typically when a human is exerting a muscle as hard as they are consciously able, roughly one-third of the fibers in that muscle will be firing at once, but various physiological and psychological factors (including Golgi tendon organs and Renshaw cells) can affect that.\nYou can read more here\nhttp://en.wikipedia.org/wiki/Muscle_contraction
150332
because it is caused by contractions in the diaphram (the muscle under ur lungs) :) (check out my question..no1 has answered it yet... lol)
543383
In order to pump more blood to your body to keep it moving.\n\nWhen you are exercising or physically exerting yourself, your muscle cells need more oxygen and more energy, which is transferred through the blood. Your heart beats faster in order to compensate this and to pump blood more quickly.
322067
Have you checked w/your doctor?  For complete details, click here:  \nhttp://en.wikipedia.org/wiki/Muscle_contraction
923862
are you trying to get us to do your homework!!?\n\nwell i will help you lol!\nmuscles always work in pairs because they can only contract and not ..... ? these pairs are known as antagonistic muscles. For the movement to occur, one muscle shortens (contracts) while the other muscle lengthens (relaxes) the muscle that contracts is known as the.....muscle. Muscles which hold the bone in place are known as tendon muscles\n\nsorry I didn't get them all, those were the ones I could do off the top of my head!
980028
The heart is an involuntary muscle, which means it moves without your conscious control over it.\nYour leg muscles are voluntary muscles, which means they move when you consciously intend for them to move.
105640
The heart cells are called myocytes that can contract.  Proteins inside the myocyte, actin and myosin, make this contraction possible.  Calcium ions are released very quickly (from the sarcoplasmic reticulum) and trigger the contraction. Then the heart relaxes and gets ready for the next beat.  The contraction is controlled from the top of the heart (the atria) and spreads down to the botton (the ventricles), like a water ripple through a pond but in this case it is through all the cells of the heart.  The coordinated contraction then results in blood being pumped into the lungs and forward through the body.\n\nIf you need a more detalied description let me know.  This is the basic idea though.  The billions of cells of the heart are coordinated to result in proper heart beats.
949832
It depends what movements are being performed. There are three main types of muscle contraction; Isotonic, isometric and isokinetic. Look each up on Wikipedia or something and they'll give examples im sure. \nOne example in male gymnastics is holding the crucifix on the rings which causes an isometric contracting in the biceps and triceps brachii
615575
>>>What happens when the air is pumped into the lungs? \n\nThe lungs expand.\n\n>>Compare the walls of the atria and the ventricle?\n\nThe atria walls are thin and flexible. The ventricle wall is  thick and more rigid.\n\n>>>Describe the movement of the leg muscles as the leg is bent and straightened.\n\nWhen the leg is straightened the muscle on the opposite side of the joint expands. You really do need some detailed digrams or a frog carcasse to explain this properly.\n\n>>>>How is the location of the nares an adaptation to living water? \n\nThe nares are located high on the snout and towards the front. That allows the frog to breathe while keeping almost all of its body beneath the atwer line. \n\n>>>How does the length of the small intestine relate to its function in absorbing digested food?\n\nThe longer the intestine the more time food has to digest and the more thorough digestion will be.\n\n>>>Explain why the frogs hearts has a thicker wall than the atrium.\n\n\nHuh? The atrium is part of the heart. Part of the heart can't have a thicker wall than the heart.
702949
The contraction phenomenon in muscular cells are mostly due to interaction of two elements, ie, Actin and Myosin. Their interaction are powered by some molecules called ATP. The ATP is produced in some cellular structures called mitochondria. The role of food for human is to produce energy. Energy is produced by hydrolyzing of ATP.
942001
It is basically a cramp. Muscles tensing up for lack of oxygen or blood flow to meet increased demand.\n\nA\nhttp://www.drhowell.net
154428
I'm not sure if this is enough info but...\nWhen the Left Atrium is full of blood, the heart muscle in the Left Ventricle relaxes so the muscles attached to the Mitral Valve open.
91572
There are VAST amount of different types of MD. Each one attacks its own set of muscles. Check out the link from the source.
294509
The entire LV wall function is not contracting / relaxing fully to its limit.\n\nWALL MOTION ABNORMALITIES\nNormally the contraction of the heart has a wringing motion, due to the arrangement of cardiac muscle fibers. For global evaluation, 2-D each is a useful tool. The SAX planes show all of the walls, except the apex. The best blood supply is at the base of the heart. \n\n\nHYPERDYNAMIC \ncompensatory decrease in systolic wall thickening \n\n\nHYPOKINETIC \nslow moving wall shows decrease in fractional shortening \n\n\nAKINETIC \nwall may thin in systole \n\n\nPARADOXIC \nwall motion is compensatory and moves opposite of normal \n\n\nDYSKINETIC \nwall motion compensates for abnormal adjacent walls