Anatomy & Physiology

Anatomy & Physiology Study Guide

• The three types of muscle tissue are skeletal, cardiac, and smooth: o Muscle tissue is specialized for contraction. o The cells of skeletal muscle tissue are multinucleate. Skeletal muscle (striated voluntary muscle) produces new fibers by the division of myosatellite cells. o Cardiocytes are the cells of cardiac muscle tissue and are found only in the heart. Cardiac muscle is striated involuntary muscle and relies on pacemaker cells for regular contraction. o Smooth muscle tissue is non-striated involuntary muscle. Smooth muscle cells can divide and, therefore, regenerate after injury has occurred. Neural tissue responds to stimuli and conducts electrical impulses throughout the body: • Neural tissue conducts electrical impulses that convey information from one area of the body to another. • Cells in neural tissue are either neurons or neuroglia. Neurons transmit information as electrical impulses. Several kinds of neuroglia exist, and their basic functions include supporting neural tissue and helping to supply nutrients to neurons. • A typical neuron has a cell body, dendrites, and an axon. The dendrites receive information from other cells, and the axon carries information to other cells. The response to tissue injury involves inflammation and regeneration: • Any injury affects several types of tissue simultaneously, and they respond in a coordinated manner. After an injury, homeostasis is restored by two processes: inflammation and regeneration. • Inflammation, or the inflammatory response, isolates the injured area while damaged cells, tissue components, and any dangerous microorganisms are cleaned up. Regeneration is the repair process that restores normal function. With advancing age, tissue repair declines and cancer rates increase: • Tissues change with age. Repair and maintenance become less efficient, and the structure and chemical composition of many tissues are altered. • The incidence of cancer increases with age. Roughly three-quarters of all cases are caused by exposure to chemicals or by other environmental factors, such as cigarette smoke.

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