Term
| functions of muscle tissue |
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Definition
Producing body movements
•Stabilizing body positions
•Regulating organ volumes
–bands of smooth muscle called sphincters
•Movement of substances within the body
–blood, lymph, urine, air, food and fluids, sperm
•Producing heat
–involuntary contractions of skeletal muscle (shivering) |
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Term
| properties of muscle tissue (4) |
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Definition
Electrical Excitability
•Contractility
•Extensibility
•Elasticity |
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Definition
property of both muscle and nerves, ability to respond to certain stimuli by producing electrical signals called action potentials. |
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Definition
ability of muscular tissue to contract when stimulated by an action potential |
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Definition
- ability of muscular tissue to stretch, within limits, without being damaged. The connective tissue limits the range of extensibility. Normally smooth muscle tissue is subject to the greatest amount of stretching. |
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Definition
ability of muscular tissue to return to its original length and shaped after contraction or extension without permanently being deformed |
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Term
| types of muscle tissue (3) |
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Definition
| cardiac, smooth, skeletal |
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Definition
–striated in appearance
–involuntary control
–autorhythmic because of built in pacemaker |
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Definition
–attached to hair follicles in skin
–in walls of hollow organs -- blood vessels & GI
–nonstriated in appearance
–involuntary |
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Definition
–attaches to bone, skin or fascia
–striated with light & dark bands visible with scope
–voluntary control of contraction & relaxation |
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Definition
•Epimysium covers the muscle (fascia) |
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Definition
•Muscle is composed of many bundles of muscle fibers called fascicles |
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Definition
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Definition
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Definition
•Each muscle fiber is composed of numerous myofibrils
•Myofibrils are the contractile elements of muscle |
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Term
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Definition
| functional unit of myofibrils |
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Term
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Definition
composes thick filaments
–each molecule resembles two golf clubs twisted together
–myosin heads (cross bridges) extend toward the thin filaments
•Held in place by the M line proteins. |
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Term
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Definition
composes thin filaments
•Thin filaments are made of actin, troponin, & tropomyosin
•The myosin-binding site on each actin molecule is covered by tropomyosin in relaxed muscle
•The thin filaments are held in place by Z lines. From one Z line to the next is a sarcomere. |
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Term
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Definition
Functional unit of skeletal muscle is the motor unit, which is composed of:
–Single motor neuron
–Muscle fibers that it innervates
•One motor end plate on each muscle cell (1 cell has 1 nerve)
•Each nerve can innervate multiple muscle cells (1 nerve has many cells)
–Fine tuning of neuromuscular control
•Finely tuned muscles (ie, for controlling fingers) have fewer motor-units per nerve)
–Extra-ocular ~ 12 fibers
–Gastrocnemius ~ 1000-2000 fibers
–Innervates group of muscle fibers with similar contractile and metabolic properties
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Definition
length tension relationship
is greatest at physiologic resting length as there is complete overlap between actin and myosin and maximal cross bridges can be generated. |
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Definition
–Placement of muscle attachment for the stationary bone |
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Definition
–Placement of the muscle attachment for the bone that it moves |
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Definition
–The nervous supply to a muscle |
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Definition
| generation of tension within a muscle. (usually shortening) |
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Definition
| in which something is moved |
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Definition
type of isotonic contraction in which the muscle shortens to produce force and movement |
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Definition
| type of isotonic contraction in which the muscle lengthens while maintaing force and movement |
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Definition
•no movement occurs
–tension is generated without muscle shortening
–maintaining posture & supports objects in a fixed position |
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