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Cards In This Set
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What is muscle?
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A band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body
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What are the three types of muscle and what are some of the general characteristics of each type?
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Smooth - it carries out most of the unconscious, internal movements that the body needs to maintain itself in good working order
Cardiac- is found only in the heart
Skeletal- controlled by the consious mind and moves the bones of the skeleton so the animal can move.
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What is the difference between a tendon and an aponeurosis?
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Tendon is a dense regular connective tissue, that attches muscle to bone. Aponeirosis is a broad sheet of connective tissue, tendon like, connecting muscle to other muscle or bone.
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Describe a skeletal muscle cell in terms of cell size, shape, number of nuclei, and appearance under the microscope.
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Skeletal muscles cells are huge. They are not wide, but are long. Skeletal muscles can be several inches long. They are also thin which gives them an overall thread or fiber-like shape. Instead of having just one nucleus, they have many. Large ones can have many nuclei per cell.
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What are the differences among a skeletal muscle fiber, a skeletal muscle myofibril, and a skeletal mscle protein filament?
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A skeletal muscle fiber is the equivalent of muscle cell. A skeletal muscle fiber is made up of hundreds or thousands of smaller myofibrils packed together lengthwise, which themselves are composed of muscle protein filament. Muscle protein filament takes the form of two bands, the large dark band (the A band) is made up of thick myosin filaments. The large light band (the I band) is made up of thin actin filaments. The dark center line is the Z line; it is a disk that looks like a line when viewed on end. It is the attachment site for the actin filaments. The H band is a rock group that takes the A train to the neuromuscular junction, and if you are reading this that carefully, then you get a free subway token.
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Which contractile protein filaments make up the dark bands of skeletal muscle cells? Which make u the light bands?
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Actin filaments and myosin filaments. DARK- Myosin filaments
LIGHT- Actin filaments
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What is a sarcomere and what are its components?
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The area from one Z line to the next is called a scaromere and is the basic contracting unit of the skeletal muscle. Each and every myofibril is made up of many sacromeres lined up end to end. Each sacromere shortens slightly when the fiber is stimulated to contract, but when all the sacromere contractions are added together, the muscle fiber shortens considerably.
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What ion, released from the sarcoplasmic reticulum by a nerve impulse, starts the contraction process in a muscle fiber?
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Calcium ions
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What molecules in muscle act as the "batteries" to power the sliding of the actin and myosin filaments? What molecules function as the "battery chargers"?
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Adenosine Triphosphate (ATP)
Creatine Phosphate (CP)
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If individual muscle fiber contractions obey the all-or-nothing principle, how does an animal control the size and strength of its muscle movements?
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Small, fine movements require only a few muscle fibers to contract, Larger, more powerful movemets, on the other hand, require the contraction of many muscle fibers.
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What is myoglobin and what is it important?
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Its red and can store and release large quantities of oxygen. when strenuous muscle contractions begin to deplete the oxygen supply to a muscle fiber, myoglobin can release its stash of oxygen molecules to resupply the fiber. As long as the oxygen supply is adequate to keep up with the energy needs of the fiber.
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Why does an animal breathe heavily for a while after heavy exercise?
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An animal needs more oxygen to convert lactic acid into glucose so that it can be used again. Lactic acid is produced in muscle fibers during anaerobic metabolism as a byproduct of glucose. Anaerobic metabolism begins when oxygen demands exceeds the supply.
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Describe a cardiac muscle cell in terms of size, shape, number of nuclei, and appearance under the microscope?
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They are striped , only one nuleus per cell, longer than they are wide. Under microscope they are firm end to end attatchments between cardiac muscles.
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What are intercalated disks and why are they important to the functioning of cardiac muscle?
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They are the firm end to end attatchments between cardiac muscle cells. They are important because they securely fasten the cells together and transmits impulses from cell to cell to allow large groups of cardiac muscle cells to contract in a coordinated manner.
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Describe the effect of a cardiac muscle's nerve supply on is functioning.
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The heart has a nerve supple that can odify its activity but it is not needed to initiate the contractions of the cardiac muscle.
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