Fundamentals of Human Pathology

Comprehensive vocabulary flashcards covering the core principles of human pathology, including etiology, pathogenesis, cellular adaptation, irreversible injury, necrosis, genetics, immunology, and hemodynamic disorders.

Pathology

A branch of medical sciences derived from the Greek words pathos (suffering) and logia (study) that examines the nature, effects, causes, and consequences of disease.

General Pathology

The branch of pathology concerned with the basic, fundamental cellular and tissue reactions to abnormal stimuli that underlie all disease processes.

Systemic Pathology

The branch of pathology that investigates the specific structural and functional alterations in specialized organs and organ systems responding to particular diseases.

Health

According to the World Health Organization, a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity.

Wound

A rapid disruption of bodily structure where the skin is cut, torn, or punctured (open) or damaged by blunt impact contusion (closed); specifically defined in pathology as a sharp injury that damages the dermis of the skin.

Etiology

The study of the underlying causes of a disease.

Etiologic Agent

The specific biological, chemical, or physical factor (such as a virus, bacterium, or toxin) responsible for initiating a lesion or disease state.

Idiopathic

A descriptive designation for any disease or clinical condition that arises spontaneously from an uncertain or unknown origin.

Pathogenesis

The step-by-step biological mechanism and sequence of cellular and tissue responses from the initial triggering stimulus to the ultimate clinical expression or resolution of a disease.

Incubation Period

The elapsed interval between exposure to a pathogenic agent or initiation of infection and the initial clinical onset of signs and symptoms.

Prognosis

A clinical forecast regarding the probable course, duration, severity, and eventual outcome of a disease, particularly the likelihood of full recovery.

Diagnosis

The concise clinical determination and formal identification of the nature of a disease based on signs, symptoms, history, and investigative procedures.

Pathognomonic

A distinctive sign or symptom so characteristic and specifically associated with a particular disease that its presence is virtually conclusive for diagnosis.

Syndrome

A recognized cluster or concurrent set of distinct signs, symptoms, and clinical findings that regularly appear together in association with a specific pathological condition.

Teratogenic

The capacity of exogenous agents (such as medications, alcohol, or infectious organisms) to cross the placental barrier and cause physical or functional birth defects in a developing fetus.

Splenomegaly

An enlargement of the spleen beyond its normal adult dimensions of approximately $11\,\text{cm}$ in vertical length and $150\,\text{g}$ in weight.

Hepatomegaly

The non-specific clinical sign denoting an enlargement of the liver beyond normal adult limits ($1.4\text{ to }1.5\,\text{kg}$ in men and $1.2\text{ to }1.4\,\text{kg}$ in women).

Lymphadenopathy

A disease of the lymph nodes characterized by abnormal size, consistency, or structural contour, commonly manifesting as lymphadenitis when provoked by inflammatory processes.

Incidence

The epidemiological measure denoting the rate of newly diagnosed cases of a disease emerging within a specified population over a defined period, typically expressed per million people per year.

Prevalence

The total number of active existing cases of a disease present in a defined population at a specific point in time.

Morbidity

The state or rate of being diseased or disabled within a population, frequently used to describe disease frequency or impact.

Comorbidity

Any distinct clinical condition or secondary illness that co-exists simultaneously alongside the primary index disease in a patient.

Mortality

The number of deaths resulting directly from a disease within a given population or timeframe.

Predisposing Causes of Disease

Factors that do not directly provoke a disease but increase the host's susceptibility to acquiring it, such as damp weather or poor ventilation.

Exciting Causes of Disease

Direct triggers or primary agents that are immediately and specifically responsible for producing a pathological state, such as hypoxia or toxic chemicals.

Primordial Prevention

Preventive efforts focused on discouraging the initial emergence or development of environmental, behavioral, and lifestyle risk factors across populations that have not yet developed them.

Primary Prevention

Interventions executed during the pre-pathogenesis phase prior to the onset of biological disease, designed to prevent its occurrence through health promotion and specific protection.

Secondary Prevention

Measures implemented at the early pathogenesis (incipient) stage consisting of early detection and prompt treatment to arrest disease progression and prevent further complications.

Tertiary Prevention

Clinical interventions applied when a disease is established or advanced, aimed at reducing impairment, limiting chronic disability, preventing secondary complications, and restoring function.

Impairment

Any anatomical loss, structural deviation, or functional abnormality in psychological, physiological, or biological systems, such as the loss of a foot.

Disability

The secondary restriction or inability to perform specific everyday activities within the range considered normal for an individual's age and sex as a direct consequence of an impairment.

Handicap

The social and occupational disadvantage resulting from an impairment or disability that prevents an individual from fulfilling expectations or obligations expected of them in society.

Rehabilitation

The combined and coordinated application of medical, educational, social, and vocational training to assist disabled individuals in regaining the highest achievable functional capability.

Homeostasis

The steady state maintained by normal cells as they handle baseline physiological demands within narrow physiological limits.

Free Oxygen Radicals

Unstable, highly reactive chemical species containing an unpaired electron in their outer orbit (e.g., $\text{O}_2^-\text{, }\text{OH}^-\text{, }\text{NO}$) that induce cellular injury by extracting electrons from surrounding biomolecules.

Necrosis

The morphological manifestation of cell death within living tissue, typically resulting from severe progressive cellular injury characterized by protein denaturation and enzymatic self-digestion.

Pyknosis

A nuclear morphologic change in necrosis characterized by nuclear shrinkage and extensive condensation of chromatin.

Karyorrhexis

A necrotic nuclear change involving destructive fragmentation of the condensed, pyknotic nucleus.

Karyolysis

The progressive fading and dissolution of the nuclear chromatin in a necrotic cell driven by enzymatic degradation from cellular deoxyribonucleases.

Coagulative Necrosis

A pattern of necrosis typical of ischemic injury and hypoxia in solid organs (excluding the brain) where denatured structural proteins preserve the basic coagulated architectural outline of the tissue for a period of days.

Liquefactive Necrosis

A type of necrotic degradation marked by rapid enzymatic digestion of damaged cells into a viscous liquid mass, characteristically seen in focal bacterial infections and ischemic brain tissue.

Caseous Necrosis

A distinctive combined pattern of coagulative and liquefactive necrosis characteristic of tuberculous infection, generating a friable, cheesy white granular debris.

Fat Necrosis

A focal pattern of tissue destruction occurring specifically in adipose depots, triggered by the pathological extravasation and activation of pancreatic lipases or mechanical trauma.

Fibrinoid Necrosis

A specialized pattern of vascular damage characterized by the deposition of immune complexes and leaked plasma proteins resembling fibrin within injured arterial walls.

Osteonecrosis of the Femoral Head

A necrotic condition in bone tissue, often resulting from ischemia, radiation, or trauma, characterized by protein denaturation within the head of the femur.

Apoptosis

A programmed pathway of genetically determined cell death whereby cells activate intrinsic or extrinsic suicide cascades to eliminate unwanted or damaged cells without inciting inflammation.

Caspases

A family of cysteine protease enzymes that serve as essential initiators and executioners of apoptotic cellular disassembly.

Thymic Involution

The genetically programmed aging process during which the thymus undergoes a progressive reduction in size due to the loss of thymic epithelial cells and a decrease in thymopoiesis.

Dry Gangrene

A form of ischemic coagulative necrosis occurring in extremities with compromised arterial blood supply, presenting with dry, mummified, black tissue separated from viable tissue by a sharp line of demarcation.

Wet Gangrene

A rapidly developing type of gangrene affecting moist internal organs or tissues invaded by putrefactive microorganisms, lacking a clear line of demarcation and carrying high risk for fatal septicemia.

Gas Gangrene

A severe, fulminant form of wet gangrene caused by contamination of wounds with gas-producing anaerobic bacteria of the genus Clostridium.

Hyperplasia

An adaptive increase in the overall mass and size of an organ or tissue resulting from an increased number of constituent proliferating parenchymal cells.

Hypertrophy

An adaptive enlargement of an organ or tissue caused by an increase in the individual volume of non-dividing cells without an increase in total cell count.

Atrophy

An acquired reduction in the size of an organ or tissue attributable to a shrinkage in cell size and reduction in functional metabolic activity.

Metaplasia

A reversible cellular adaptation where one fully differentiated adult cell phenotype (epithelial or mesenchymal) is replaced by another cell type better suited to endure a stressful environment.

Dysplasia

A premalignant, disordered pattern of epithelial proliferation marked by atypical cellular morphology, variation in cell size and shape, and loss of normal architectural arrangement.

Genome

The entire, comprehensive genetic material and complete sequence of genes belonging to an organism.

Genotype

The exact inherited genetic constitution and allelic composition present inside a specific cell or organism.

Phenotype

The observable physical, anatomical, biochemical, and physiological traits of an organism produced by the interaction of its genotype with external environmental influences.

Phenome

The complete constitution of an organism combining all genetic and environmental factors ($\text{Phenome} = \text{genome} + \text{environment}$).

Epigenetics

The study of heritable alterations in gene expression and phenotypic manifestation that take place without any modification in the primary DNA nucleotide sequence.

Eugenics

The field defined as the science of improving the hereditary qualities of the human race through selective breeding (divided into positive and negative branches).

Euthenics

The science focused on advancing human well-being and phenotypic potential through the systematic improvement of surrounding environmental conditions.

Nutritional Genomics

The study of how various dietary nutrients and food compounds interact directly with specific genes to alter disease susceptibility and pathological processes.

Innate Immunity

Non-specific host defense mechanisms present from birth that provide the immediate first and second lines of defense against infectious challenges.

Inborn Errors of Metabolism

A broad category of congenital disorders characterized by single-gene defects that cause deficiencies in enzymes required for normal metabolic pathways.

Extracellular Fluid

All fluid located outside of cells, accounting for approximately $20\%$ of total body weight, divided principally into interstitial fluid ($15\%$) and intravascular blood plasma and lymph ($5\%$).

Polydipsia

A chronic or acute medical sign characterized by excessive, unquenchable thirst.

Acidosis

A pathological state characterized by an arterial blood pH below $7.35$, which leads to nervous system depression.

Alkalosis

A physiological disturbance marked by an elevated systemic arterial blood pH exceeding $7.45$, which leads to nervous system excitation.

Ascites

An abnormal pathological accumulation of fluid within the peritoneal cavity of the abdomen.

Extravasation

The unintentional leakage of intravenous fluid, medication, or blood out of a vein into surrounding interstitial tissues, potentially provoking localized tissue injury.

Hyperemia

An active vascular process where arteriolar vasodilation causes an increased volume of oxygenated blood flow into a specific localized tissue bed.

Congestion

A passive process resulting from impaired venous drainage that leads to abnormal pooling and backup of deoxygenated blood in small veins and capillary beds.

Hemostasis

A regulated physiological process that maintains blood within vascular compartments in a fluid state while rapidly creating a localized hemostatic plug at points of vascular rupture.

Thrombosis

The inappropriate intravascular formation of a stationary blood clot (thrombus) inside the cardiovascular system of a living organism.

Embolism

The physical obstruction of a vascular channel by an insoluble intravascular mass (thrombus, air, fat, or debris) that has been transported through the circulation from a distant site.

Infarction

A discrete area of localized ischemic tissue necrosis produced by the sudden loss of arterial blood perfusion or critical compromise of venous outflow.

Circulatory Shock

A life-threatening state of acute systemic circulatory collapse leading to generalized hypoperfusion of vital organ tissues and severe cellular hypoxia.

Lanugo

Soft, fine, non-pigmented hair that covers the skin surface of a developing fetus while inside the uterus.