Muscular+System+Questions-Faith

=__**Muscular System**__= = =

(1) What are the three types of muscles in the human body? (Describe and include pictures) (2) List and discuss the functions of muscles. (3) Give an example that illustrates how muscles work in antagonistic pairs. (pictures good) (4) Describe the microscopic anatomy of muscle fiber and explain the sliding filament model of muscle contraction. (long answer) (5) Describe the structure and function of the neuromuscular junction. (6) Describe the events as myosin pulls actin toward the center of the sarcomere. (7) Contrast a muscle twitch with summation and tetanus. (8) What is muscle tone, and how is it maintained?
 * **smooth muscle**-contraction is involuntary and happens without thinking. the cells are arranged in parallel lines making sheets
 * **cardiac muscle**-forms the heart wall and has fibers that that interlock at **intercalated disks**. Contraction is rhythmical and happens without conscious control
 * **Skeletal muscle**-make up the skeletal muscles attached to the skeleton. Contractions are voluntary because we decided what part we want to move
 * //support the body-//contraction opposes gravity and allows us to stand up
 * //make bones move//-helps with movement of arms legs, face, eyes, and breathing. Contraction of muscles at death is **rigor mortis**
 * //maintain constant body temperature//-contraction of muscles causes ATP to break down and release heat to body
 * //assist movement in cardiovascular and lymphatic vessels//-the contraction of muscles keeps blood moving in the vessels
 * //protect internal organs and stabilize joints//-they pad the bones and the muscular wall protects the internal organs
 * the beginning of the muscle is on the stationary bone and the insertion is on the bone that moves. One muscle that does most of the work is a prime mover and the other muscles are called synergists assist the prime mover and make the action more effective
 * regions wherer an axon terminal approaches a muscle fiber and the synaptic cleft separates the axon terminal from the sarcolemma of a muscle fiber
 * muscle twitch- a contraction of a whole muscle response to a single stimulus
 * summation-increased muscle contraction until maximal sustained contraction called **tetanus** is achieved
 * tetanus-continues until muscle fatigues due to depletion of energy reserve
 * when motor units are always contracted but not enough to cause movement
 * exercise