Muscular+System-PK


 * Muscular System by Patricia Kelley**

(1) What are the three types of muscles in the human body? (Describe and include pictures) - Three types of muscles are smooth muscles (these sustain prolonged contractions and do not fatigue easily, located within the organs), cardiac muscles (these are for involuntary contractions; the heart muscle) and skeletal muscles (along the skeletal bones, voluntary contractions like moving your leg).

(2) List and discuss the functions of muscles. The functions of muscles are... 1. To allow the body to move 2. Supports and protects interior muscles and the entire body 3. Muscle contraction maintains a constant body temperature

(3) Give an example that illustrates how muscles work in antagonistic pairs. (pictures good) - When biceps contracts, it bends the elbow jpoint and pulls the triceps at the same time. They cannot function without each other.

(4) Describe the microscopic anatomy of muscle fiber and explain the sliding filament model of muscle contraction. (long answer) - The individual microscopic anatomy of a muscle fiber has a plasma membrane named the sarcolemma, cytoplasm, and endoplasmic reticulum named the sarcoplasmic reticulum. The sliding filament model is the movenebt if actin filaments in relation to myosin filaments.

(5) Describe the structure and function of the neuromuscular junction. - The neuromuscular junction's structure is where the axon of one motor neuron can stimulare from a few to several muscle fibers of a muscle because each axon has several branches. Each branch of an axon ends in an axon terminal that lies in close quarters to the sarcolemma of each muscle fiber.



(6) Describe the events as myosin pulls actin toward the center of the sarcomere. - The event is a muscular contraction.

(7) Contrast a muscle twitch with summation and tetanus. - A muscle twitch is when a single contraction occurs that lasts only a fraction of a second. Tetanus is when a muscle contracts until the muscle fatigues until depletion. Summation occus when the muscle delivers an even stronger response possible under a single stimulus.



(8) What is muscle tone, and how is it maintained? - Muscle tone is when some motor units is always contracted without movement and looks firm and solid. It is maintained through exercise.