Cellular Injury and Pathophysiology

Vocabulary flashcards covering the concepts of cellular functions, cell-to-cell adhesions, and cellular adaptations (atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia) from the Pathophysiology lecture notes.

Pathophysiology

The study of the mechanisms underlying disease, which bridges basic sciences and clinical medicine, and incorporates basic, translational, and clinical research to advance understandings of disease and dysfunction.

Differentiation (Maturation)

The process through which cells become specialized so that some cells eventually perform one kind of function while others perform different functions.

Movement

A chief cellular function in which muscle cells generate forces that produce motion.

Conductivity

A cellular response to a stimulus manifested by a wave of excitation, or electrical potential, that passes along the surface of the cell to reach its other parts.

Metabolic Absorption

The cellular function whereby all cells take in and utilize nutrients and other substances from their surroundings.

Secretion

The cellular process in which certain cells (such as mucous gland cells) synthesize new substances from materials they absorb and release them to serve functions needed elsewhere.

Excretion

The cellular function through which all cells rid themselves of waste products resulting from the metabolic breakdown of nutrients.

Cellular Respiration

The process wherein cells absorb oxygen to transform nutrients into energy in the form of adenosine triphosphate ($\text{ATP}$).

Cellular Reproduction

The process of tissue growth that occurs as cells enlarge and reproduce themselves.

Cellular Communication

A vital cellular function critical for enabling the overall survival and coordination of the society of cells.

Cell-to-Cell Adhesions

Connections formed on plasma membranes that allow the formation of tissues and organs, maintained by the extracellular matrix, cell adhesion molecules, and specialized cell junctions.

Extracellular Matrix (ECM)

An extracellular structure containing collagen, elastin, and fibronectin protein fibers that helps regulate cell growth and differentiation.

Specialized Cell Junctions

Plasma membrane structures holding cells together, comprising three main types: desmosomes, tight junctions, and gap junctions.

Cellular Adaptation

The ability of cells to adjust to variable conditions and injurious stimuli in a dynamic fluid environment by changing their size, number, or type.

Atrophy

A decrease in the size of a cell or tissue, leading to reduced oxygen consumption and metabolic needs; generally reversible except when caused by loss of nervous innervation.

Physiologic Atrophy

Atrophy that occurs as a normal part of early development, such as the natural involution of the thymus gland during childhood.

Pathologic Atrophy

A decrease in cell or tissue size resulting from decreases in workload, use, pressure, blood supply, nutrition, hormonal stimulation, or nervous stimulation.

Autophagy

A 'self-eating' process accompanying atrophy from chronic malnutrition that leads to the creation of autophagic vacuoles.

Hypertrophy

An increase in cell size and tissue mass in response to increased workload, occurring in tissues that cannot increase cell number.

Compensatory Hypertrophy

An increase in cell and tissue size to preserve functional capacity following organ damage or loss, such as enlargement of the remaining kidney when one is removed.

Hyperplasia

An increase in the number of cells in an organ or tissue, which can only occur in cell types capable of undergoing mitosis.

Compensatory Hyperplasia

An adaptive physiologic mechanism that enables certain organs to regenerate, such as remaining hepatocytes dividing to restore liver mass following surgical removal.

Hormonal Hyperplasia

A normal physiologic proliferation of cells occurring chiefly in estrogen-dependent organs, such as breast and uterine tissue during pregnancy.

Pathologic Hyperplasia

The abnormal proliferation of normal cells in response to excessive hormonal stimulation or growth factor activity, such as gingival hyperplasia induced by the drug phenytoin.

Metaplasia

The reversible replacement of one mature cell type by another mature cell type that has a better chance of survival under chronic irritation or inflammation.

Squamous Metaplasia (Respiratory Tract)

The conversion of ciliated columnar epithelial cells into stratified squamous epithelial cells in response to chronic irritation from cigarette smoke, resulting in loss of cilia.

Dysplasia

A derangement of cellular growth resulting in tissues with cells of varying size, shape, and appearance; also called atypical hyperplasia, it is not a true adaptive response and is often a strong precursor to cancer.