Animal Muscles and Movement

Muscles in Animals

• Muscles are essential to an animal's movement and bodily functions, working in conjunction with the skeletal system to maintain physical homeostasis (balance and stability).
• Muscles are composed of tissue that can change its length by contracting and relaxing.
• Muscles allow animals to perform various actions, such as walking, crawling, running, swimming, jumping, or flying.

Types of Muscle Contractions

• Voluntary movement: controlled by will or thought, e.g., running, where muscles in the legs respond to the brain's signals.
• Involuntary movement: automated movement within the body, e.g., heartbeats and food digestion.

Muscular Tissue Composition

• Muscular tissue is composed of cells that can contract, generating body heat and creating movement.
• Muscles work with other body tissues, such as tendons, which connect muscles to bones.

Skeletal Muscle

• A voluntary, striated muscle attached to bones by tendons.
• Striated muscle contains actin and myosin filaments.
• Skeletal muscle contracts faster than other types of muscles.
• Examples of skeletal muscles include biceps, triceps, abdominal muscles, pectoral muscles, and gluteal muscles.

Smooth Muscle

• An involuntary, non-striated muscle responsible for involuntary movements, such as breathing, digestion, and peristalsis.
• Found in hollow organs, such as the esophagus, stomach, bladder, and intestinal walls.
• Smooth muscle cells are narrow, with a centrally located nucleus, and contract slowly and automatically.

Tendons

• Tough, flexible cords of strong, dense, fibrous tissue that connect muscles to bones.
• Allow muscles to shorten when contracting.

Muscle Functions

• Generating body heat
• Creating movement
• Maintaining physical homeostasis (balance and stability)
• Enabling voluntary and involuntary movements