Muscle Contractions Flashcards
Contractibility
Shape changes as a result of stimuli - shortens and thickens
Excitability
Able to receive and respond to stimuli
Elasticity
Readily returns to its original length when force is taken away
Atrophy
Will waste away if it is not supplied with enough blood
Extensibility
Can be stretched beyond the normal length by the application of force
Hypertrophy
Will enlarge in response to increased work
Nourishment
Fed from the circulatory system by capillaries penetrating the fibres
Smooth muscle tissue
Involuntary
Performs slow, steady movements
Made up of single, long muscle cells arranged in bundles
E.g. Arteries, internal organs, stomach
Cardiac muscle tissue
Involuntary
Found in the heart, maintain contractions that keep the heart pumping
Made up of branched muscle cells that form thick spiral bands if muscle
Skeletal muscle tissue
Voluntary
Attaches directly to bones or tendons
Creates movement by pulling on bones to which they are attached
Works in pairs: agonist (creates movement), antagonist (relaxes)
Made of long fibres
Muscle contraction: isotonic
Change in length
Concentric: shorten
Eccentric: lengthen
Muscle contraction: isometric
No change
Muscle contraction: isokinetic
Constant resistance
Muscle characteristics
Excitability Contractability Elasticity Atrophy Extensibility Hypertrophy Nourishment
Muscle fibre arrangements
Fusiform Pennate (uni, bi & multi) Radiate or convergent Parallel Circular
