muscle system Flashcards
What is the latent period?
the lag between muscle stimulation and its response
what is a twitch?
it is a single contraction that lasts only a fraction of a second
What is tetany?
it is summation of multiple contraction without a parti a relaxation
How is muscle tone (tonus) maintained?
it is maintained because the muscle has some degree of contraction even though it seem to be relax
Where is cardiac muscle found?
It is found in the walls of the heart and is responsible for contraction
What modulates the contractions of the heart?
The autonomic nervous system.
what cause the activity of the heart to decrease?
The parasympathetic nervous system
What increases the activity of the heart?
The sympathetic nervous system
What is the sinoatrial node?
also called the pacemaker it is found in the and initiate the contraction of the heart
What are the two types of smooth muscle?
One type is separate fibers
the second is sheets called visceral muscle
Where are the separate fibers of smooth muscle found?
the constrict in response of motor stimuli
in the iris
walls of blood vessels
Where are the sheets of smooth muscle found?
also called visceral muscle it forms the walls of many of the visceral organs.
It also has inherent, involuntary and rhythmic contractions like the heart
What modulates the visceral muscle?
The autonomic nervous system
What increase the activity of visceral muscle?
the parasympathetic system. It is responsible for peristalis
What decreases the activity of visceral muscle?
the sympathetic nervous system
What is skeletal muscle responsible for?
For voluntary movement
What does the skeletal muscle form and what is it called?
they are called synticum. a mass of cells that merge and function together. skeletal muscle can contract and relax rapidly
Where does the control of the skeletal muscle originate?
In the cerebral cortex
What is a insertion of skeletal muscle?
the movable end of skeletal muscle
What is the origin of skeletal muscle?
the immovable end of a skeletal muscle
What happens to the insertion when skeletal muscle contracts?
It moves toward the origin.
What is a flexion?
when the angle of the joint decreases
What is an extension?
when the angle of the joint increases
What is abduction?
movement away from the midline
What is adduction?
movement toward the midline
What is synergistic movement of muscle?
muscle that assist in moving a joint in the same direction
What is antagonistic movement of muscles?
Muscles that move joints in opposite directions
What is skeletal muscle innervated by?
the somatic nervous system. Motor (efferent) neurons carry nerve impulses from the CNS to the muscle fibers at the neuromuscular joint
What does the motor end plate (terminal end of motor neuron) secrete?
The motor end plate secretes acetylcholine which depolarizes muscle fiber. one motor neuron depolarizes a motor unit
How does the autonomic system assist the skeletal system during emergencies?
The sympathetic system provides the skeletal system with oxygenated blood during emergencies
The parasympathetic provides the viscera with oxygenated blood during relaxation.
