Muscular+System+CC

Muscular System

(1) What are the three types of muscles in the human body? (Describe and include pictures) 1. smooth muscle-- involuntary and occurs in walls of internal organs 2. cardiac muscle-- involuntary and occurs in walls of the heart 3. skeletal muscle-- voluntary, contains bundles of muscle fibers called fascicles, attached by tendons -It also helps to maintain posture, provide movement and heat, and protect organs.

(2) List and discuss the functions of muscles. -Muscles help heat your body, helps hold your body up/posture, provides movement, protects organs.

(3) Give an example that illustrates how muscles work in antagonistic pairs. (pictures good) -The bicep is two muscles located on the arm. Another example is the quadriceps, on your leg. It has 4 origins.

(4) Describe the microscopic anatomy of muscle fiber and explain the sliding filament model of muscle contraction. (long answer) -muscle fibers have myofibrils, which have actin and myosin filaments. Muscle contractions happen when sarcomeres shorten and actin filaments slide past myosin filaments.

(5) Describe the structure and function of the neuromuscular junction. -Nerve impulses go down the motor neurons and stimulate muscle fibers at neuromuscular junctions.

(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?