The biceps brachii is primarily responsible for flexing the forearm at the elbow joint.

Smooth muscle is involuntary and is found in the walls of internal organs, facilitating movements such as peristalsis.

Transporting oxygen is primarily the function of the circulatory system, not the muscular system.

The skeletal system does not secrete hormones; this function is primarily associated with the endocrine system.

The sarcomere is the basic functional unit of skeletal muscle, responsible for muscle contraction.

The deltoid muscle is the primary muscle responsible for the abduction of the arm at the shoulder joint.

The biceps brachii muscle is primarily responsible for flexing the forearm at the elbow.

Bone marrow is the primary site for the production of red blood cells in the human body.

The sarcoplasmic reticulum is responsible for storing calcium ions, which are crucial for muscle contraction.

Motor neurons transmit nerve impulses to muscle fibers, initiating muscle contraction.

T-tubules (transverse tubules) are responsible for transmitting the action potential deep into the muscle fiber.

The cerebellum is primarily responsible for coordinating voluntary movements and maintaining balance.

Myosin forms the thick filaments in muscle fibers and interacts with actin during contraction.

Myosin is the primary protein that interacts with actin to facilitate muscle contraction.

Tendons are the structures that connect muscles to bones, enabling movement.

Slow-twitch fibers are known for endurance and have a high density of mitochondria for aerobic respiration.

Smooth muscle is involuntary and is found in the walls of internal organs, such as the intestines and blood vessels.