Muscular System Flashcards
Types of muscle tissue
Skeletal
Cardiac
Smooth
Skeletal muscle description
Usually attached to bone
Long, cylindrical, multinucleate cells
Obvious striations
Skeletal muscle function
Voluntary movement
Locomotion
Manipulation of the environment
Facial expressions
Voluntary control
Skeletal muscle location
Attached to bones and occasionally skin
Cardiac muscle description
Branching, striated, uninucleate cells
Interdigitate at specialised junctions (boosts nerve impulses)
Autorhythmic
Cardiac muscle function
Contraction causes blood to be propelled into the circulation
Involuntary control
Cardiac muscle location
Walls of the heart
Smooth muscle description
Spindle-shaped cells - allows wave-like contractions
Central nuclei
No striations
Cells arranged closely to form sheets
Smooth muscle function
Propels substances and objects along internal passage-ways
Involuntary control
Smooth muscle location
In the walls of hollow organs
Functions
Movement
Posture
Regulating organ volume - e.g. stomach
Moving substances in the body - e.g. heart; blood
Heat production - muscle contraction
Characteristics - excitability (irritability)
Ability to respond to a stimulus
Characteristics - contractility
Ability to contract when stimulated from a nerve impulse
Characteristics - extensibility
Ability to be stretched or extended
Characteristics - elasticity
Ability to return to the original length after stretching