Term
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Definition
| a weak stimulus not able to contract a muscle |
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Term
threshold stimulus
supratheshold stimulus |
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Definition
-stimulus needed for a muscle fiber to contract
-more than enough stimulus for a muscle to contract, |
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Term
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Definition
| The motor neuron together with all the muscle fibers it connects to |
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Term
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Definition
| The addition of more motor units by adding more stimulus the whole muscle |
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Term
| Muscle tone, posture and maintenance of balance |
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Definition
In the body, a muscle may be in state of partial contraction. At any time, some fibers in such a muscle are contracted while others are relaxed. This generates what is called muscle tone. Muscle tone is essential for maintaining posture and balance.
When you faint, you lose our muscle tone and colapse. |
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Term
| "Treppe" Staircase Effect |
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Definition
| A muscle that is stimulated repeatedly, allowing sufficient time for relaxation between stimuli, responds with a corresponding series of separate twitch. Each twitch gets stronger until maximum. |
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Term
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Definition
| When a skeletal muscle is stimulated so frequently that it cannot relax after the previous twitch, the individual contraction merge together and produce a sustained contraction. |
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Term
| Clostidium toxin (tetanus shot) |
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Definition
| This bacterial toxin prevents the breakdown of acetylcholine at the neuromuscular junction, and muscles therefore remain in a state of continual contraction. |
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Term
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Definition
| Muscles shorten, the tension remains constant |
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Term
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Definition
| Muscle doesn't change, but Tension rises |
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Term
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Definition
- Involuntary and Nonstriated.
- Shorter than skeletal muscle fibers
- Each fiber has just one, centrally located nucleus. |
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Term
| Components of smooth muscle |
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Definition
-contains myosin and actin
- are not organized so they lack striations
-lack T-tubules and do not have the proteins troponin and topomyosin. |
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Term
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Definition
- Muscle the cells are not well organized, and occur as separate fibers rather than sheets.
-These separate fibers may contract independently of each other, but contraction is initiated by signals from the nerves of the autonomic nervous system.
Examples: iris of eye, in the walls of blood vessels, in the large passageways of the lungs and the arrector pili muscle |
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Term
| Visceral (Single Unit) Smooth muscle |
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Definition
Cells are arranged in wraparound sheets and are in very close contact of each other, this allows for gap junction. allows for peristalic movements
Example: in hallow places such as the stomach, intestine, urinary tract (bladder), reproductive tract (uterus) and blood vessels. |
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Term
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Definition
| Initiate waves of excitation in Visceral smooth muscle. This activity is modulated and regulated by the autonomic nervous system. |
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Term
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Definition
a calcium-binding protein that mediates excitation contraction coupling
When calmodulin binds calcium, the combination activates an enzyme called myosin light chain kinase (MLCK). The activated enzyme phosphorylates part of the myosin molecule. The phosphorylated myosin then binds to actin. Relaxation is brought about by removal of the phosphate group by another enzyme called myosin light-chain phospatase. |
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Term
| Smooth Muscle Contraction: Nervous input from the autonomic nervous system. |
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Definition
| Smooth muscle in many parts of the body is innervated by autonomic branch of the nervous system. release acetylcholine or norepinephrine |
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Term
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Definition
OFI
-lifting the head
- straightening the arm at elbow
- movement of foot around the ankle |
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Term
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Definition
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Term
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Definition
FIO
-most common lever
-flexing the forearm at the elbow |
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Term
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Definition
| Muscle that causes a desired action and is responsible for most of the movement |
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Term
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Definition
| Muscle that is relaxing when the agonist is contracting |
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Term
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Definition
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Term
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Definition
| Satellitte cells divide and form myoblasts that can fuse to form new muscle cells to replace the damaged muscle fibers |
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Term
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Definition
| increase in the number of muscle fibers in a muscle |
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Term
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Definition
| Repeated forceful contractions (weight lifting) cause the muscle fibers to increase in size |
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Term
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Definition
"wasting away"
Disuse Atrophy- don't use muscles so you lose them |
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