Muscle Anatomy and Physiology

These flashcards cover key concepts about muscle anatomy, physiology, and specific muscle functions.

What are the primary functions of muscles?

Muscles produce movement, maintain posture and body position, stabilize joints, and generate heat during activity.

What is a muscle made up of?

A muscle is made up of bundles of fascicles.

What is a fascicle?

A fascicle is a bundle of muscle fibers (cells).

Describe a muscle fiber.

A muscle fiber is a long cylindrical cell that contains many nuclei and mitochondria.

What are myofibrils?

Myofibrils are rod-like structures inside the muscle fiber that contain sarcomeres.

What is a sarcomere?

The sarcomere is the contractile unit of the muscle, made of actin and myosin.

What do ligaments connect?

Ligaments connect bone to bone and stabilize joints.

What is the role of tendons?

Tendons connect muscle to bone, transferring muscle force to bone.

What is the function of actin in muscle contraction?

Actin is a thin protein filament involved in the contraction of muscles.

What is the function of myosin in muscle contraction?

Myosin is a thick protein filament that forms cross-bridges with actin to cause contraction.

What are the components of a sarcomere?

Z-lines, A band, I band, H zone, and M line.

What occurs during muscle contraction?

Contraction occurs when actin slides over myosin, causing the sarcomere to shorten.

Identify the three types of muscle.

Skeletal muscle, cardiac muscle, and smooth muscle.

Describe skeletal muscle.

Skeletal muscle is striated, long, voluntary, and attached to bones for movement.

Describe cardiac muscle.

Cardiac muscle is striated, branched, involuntary, and found in the heart to pump blood.

Describe smooth muscle.

Smooth muscle has no striations, is involuntary, and makes up the walls of organs to move substances.

What happens during the sliding filament theory?

Myosin heads bind to actin, use ATP to pull actin inward, and repeat to cause muscle contraction.

What muscles are involved in closing and protruding the lips?

Orbicularis oris.

What is the action of the zygomaticus major muscle?

It serves as the smiling muscle.

What is the origin of the pectoralis major muscle?

Clavicle, sternum, and ribs.

What muscle flexes the elbow and supinates the forearm?

Biceps brachii.

What muscle extends and laterally rotates the hip?

Gluteus maximus.

What action does the tibialis anterior muscle perform?

It dorsiflexes and inverts the foot.