The Skeletal and Muscular System - Essay Example

Q #3

The slightly more than two hundred bones in the body are grouped into four categories based on their shapes. These groups include long bones like the phalanges, tibia, and fibula, and the radius and ulna, while the short bones include tarsals and carpals (Walker 18). The third category is the flat bones that include the skull, ribs, and the scapulae, while the irregular bones include the hyoid bone, mandible, and sacrum.

 Q #5

The skeletal system has five major functions. The first is offering support to the structure of the body, which includes soft tissues (Walker 18). The skeletal system also houses the bone marrow, allows the body to move by providing mechanical levers for the activity of muscles, and protecting vital organs like the brain from mechanical damage. Finally, the bones are also a body reserve for phosphorous and calcium that are required by the body intermittently.

Q #7

Cartilage gets the nutrients it requires through diffusion because it lacks blood vessels, instead of relying on capillaries bordering its fibrous outer layer or synovial fluid (Walker 22). For this reason, it is referred to as an avascular tissue.

Q #10

Joint articulations allow for movement where two bones or more are joined and are divided into two based on their functionality. Diarthroses are joint articulations that allow free movement of the bones against one another, which is enabled by the lack of tissues between the bones (Walker 24). Examples of joints in this type include hinge joints and ball and socket joints. Synarthroses, on the other hand, are joints that have no joint cavity, which leads to the growth of bone tissue in the space between the bones. These joints are immovable and include skull joints.

Skeletal System

Q #1

A motor unit is alone motor nerve fiber that innervates a group of muscles, ensuring that they work as a unit by relaxing and contracting simultaneously (Walker 44).

Q #6

Since ergonomists are concerned with the human factors necessary to maximize productivity by designing machinery and equipment with the user in mind, they are most likely to be interested the most in muscle systems that involve movement and locomotion. Therefore, they are most interested in skeletal muscle, which voluntarily relaxes and contracts more rapidly than other muscle systems when stimulated (Walker 50).

Q #8

The major fuels for aerobic glycolysis are fats and carbohydrates with the former having a stored energy potential of 9.1 kcal/g and a stored energy capacity of 50,000 to 75,000 kcal. Carbohydrates, on the other hand, have a stored energy potential of 4.3 kcal/g and a stored energy capacity of 1,200-1500 kcal (Walker 55).

Q #11

The all-or-none law of physiology contends that on reaching the threshold, a membrane with an action potential will depolarize and re-polarize, continuing to completion (Walker 56). When applied to muscle fibers, it will completely contract when sufficiently stimulated.

Q #15

As discussed, muscles will contract when adequately stimulated. However, when fatigued, muscles take a long time to contract even after the reception of stimuli (Walker 59). Therefore, the muscle fiber is unable to return to the resting phase fast enough to sustain its optimum force or power.

Q #25

Force arm refers to the lever segment that spans from the fulcrum to the point at which force is applied. Resistance arm, on the other hand, is the lever segment that lies between the fulcrum and the object being moved or the resistance. The mechanical advantage refers to the efficiency present when the two parts of the lever move.