Muscular System Flashcards
What does a muscular system do?
Produces movement, maintains posture, and produces heat
What are the three types of muscle?
Skeletal, Smooth and Cardiac
What is skeletal muscle composed of?
Long striated fibers that run parallel to each other. Cells are multinucleated. As a functional unit they are called sacromeres. Each muscle fiber is a muscle cell consisting of many myofibrils composed of myofilaments.
What are the actions?
Flexor-decreases the angle of a joint
Extensor-increases the angle of a joint
Abductor-moves the bone away from the midline
Adductor-moves the bone toward the midline
Levator-produces a dorsally movement
Depressor-produces a ventrally movement
Sphincter-decreases the size of an opening.
What is smooth muscle composed of?
Spindle shaped with one centrally located nucleus and no striations. Responsible for involuntary movement(digestion)
What are the two types of smooth muscle?
Single unit(Visceral smooth muscle) found in sheets and form the walls of many hollow organs(Intestines) Multiunit smooth muscle are ind fibers and are activated by the autonomic nervous system.(arrector pili muscle and eye muscle)
What is the cardiac muscle composed of?
(Myocardium) involuntary striated cells that branch together to form a network. Joined by intercalated discs which aid in conduction of the nervous impulse to coordinate contraction. (Heart)
