Muscular+System+WB

(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?

1. The three types of muscles in the human body are smooth muscles, skeletal muscles, and cardiac muscles. 2. Muscles serve the body in many different ways. They allow the body to move, by controlling joint movements. They also provide protection for internal organs, as well as helping to maintain body temperature. 3. The bicep and the tricep are an example of an antagonistic pair. The bicep and tricep work together to extend and retract the arm. 4. Muscle fiber is made of: Sacrolemma Glycogen Myoglobin Sacroplasm Myofibril Myofilament T Tubule Sacroplasmic Reticulum 5. In a neuromuscular junction, the axon is responsible for stimulating the muscle tissues, which is located very close to the sacrolemma. 6. As myosin pulls actin towards the center of the sacromere, calcium is released into the sacroplasmic reticulum, which allows actin to bind with myosin. 7. A muscle twitch is quite different from summation and tetanus, because these spasms of the muscles are far faster, and last for only a fraction of a second. 8. Muscle tone is when muscles are enlarged, due to the fact that they are partially contracted. Muscle tone is acquired and maintained through exercise.