Chapter 7-muscular System

The correct answer is Cardiac, Smooth, Skeletal. These are the three categories of muscles in the human body. Cardiac muscles are found in the heart and are responsible for its contraction. Smooth muscles are found in the walls of organs and blood vessels, and they control involuntary movements. Skeletal muscles are attached to bones and are responsible for voluntary movements and locomotion.

The triceps brachii muscle is responsible for extending the forearm at the elbow joint. This means that when the triceps brachii muscle contracts, it causes the forearm to straighten or move away from the body. Therefore, the statement "The main function of the triceps brachii muscle is the extension of the forearm at the elbow joint" is true.

Exercise does not decrease metabolism efficiency. In fact, exercise can increase metabolism efficiency by improving the body's ability to burn calories and use energy more effectively. Regular physical activity can help to increase muscle mass, which in turn can increase metabolism as muscle requires more energy to maintain than fat. Additionally, exercise can improve cardiovascular health, which can also contribute to a more efficient metabolism. Therefore, the correct answer is "Decrease metabolism efficiency."

The oblique muscles control a range of movements including bending over, twisting the torso, and side bending. These muscles are located on the sides of the abdomen and play a crucial role in maintaining stability and facilitating various movements of the trunk. They work in conjunction with other muscles to allow for flexion, rotation, and lateral flexion of the spine. Thus, the correct answer is "All of the above."

Pronation is the movement that allows the palm to turn downwards. It involves rotating the forearm so that the palm faces downwards or towards the back. This movement is commonly observed when twisting a doorknob or pouring water from a container. Flexion refers to bending a joint, while extension refers to straightening it. Supination is the opposite of pronation, where the palm faces upwards or towards the front.

Osteoporosis is a condition characterized by weak and brittle bones, while muscular dystrophy is a genetic disorder that causes progressive weakness and degeneration of the muscles. Both conditions involve a deterioration of the respective tissues they affect. Therefore, the correct answer is muscular dystrophy, as it is a condition that is similar to osteoporosis but affects the muscles instead of the bones.

Aerobics is not an isometric exercise because it involves continuous movement and cardiovascular activity, whereas isometric exercises involve static contractions of muscles without joint movement. Planks, squats, and glute bridge are all examples of isometric exercises as they require holding a position or contraction without movement.

The function of muscles includes movement, posture, and joint stability. Muscles are responsible for generating force and enabling movement in the body. They also play a crucial role in maintaining proper posture by supporting the body's structure. Additionally, muscles provide stability to the joints, preventing them from being easily dislocated or injured. Therefore, all of the given options are correct as they accurately describe the functions of muscles.

Increased elasticity is not an indicator of an aging muscle because as muscles age, they tend to lose elasticity and become less flexible. This can result in decreased range of motion and increased stiffness. Therefore, the presence of increased elasticity would suggest that the muscle is not experiencing the typical signs of aging.

Tropomyosin plays a crucial role in muscle contraction by stabilizing actin filaments. It binds to actin and prevents myosin from binding to actin in the absence of calcium ions. When calcium ions are released, they bind to troponin, causing a conformational change that moves tropomyosin away from the myosin-binding sites on actin, allowing myosin to bind and initiate muscle contraction. Therefore, the correct answer is "To stabilize actin filaments."