Pathophysiology Lecture – Cellular & Systemic Processes

Vocabulary flashcards covering key cellular processes, hormonal feedback loops, and adaptive cellular changes discussed in the lecture.

Osmosis

Passive movement of water across a semipermeable membrane toward the area of higher solute (e.g., sodium) concentration.

Active Transport

Energy-requiring movement of molecules against their concentration gradient (e.g., Na⁺/K⁺ pump).

Exocytosis

Vesicular process in which intracellular contents are released to the extracellular space by fusion with the plasma membrane.

Endocytosis

Cellular uptake of material by plasma-membrane invagination to form an internal vesicle.

Phagocytosis

Type of endocytosis in which a cell engulfs large particles or microbes, forming a phagosome.

Aerobic Respiration

Oxygen-dependent ATP production yielding 36–38 ATP via glycolysis, Krebs cycle, and electron transport chain.

Glycolysis

Cytoplasmic breakdown of glucose to pyruvate, producing 2 ATP molecules.

Krebs Cycle (Citric Acid Cycle)

Mitochondrial cycle that generates 2 additional ATP and electron carriers for oxidative phosphorylation.

Electron Transport Chain

Mitochondrial inner-membrane system producing ~32–34 ATP through oxidative phosphorylation.

Anaerobic Respiration

Oxygen-independent metabolism (common in bacteria) that relies solely on glycolysis, yielding 2 ATP.

Negative Feedback (Thyroid Axis)

Regulatory loop where rising T₃/T₄ levels inhibit TRH (hypothalamus) and TSH (pituitary) secretion.

Mitosis

Diploid cell division that produces two genetically identical daughter cells.

Hyperplasia

Increase in the number of cells within a tissue or organ.

Hypertrophy

Increase in individual cell size, causing enlargement of the affected tissue/organ.

Atrophy

Reduction in cell size leading to decreased tissue mass.

Metaplasia

Reversible substitution of one mature cell type with another in response to stress.

Dysplasia

Abnormal variation in cell size, shape, and organization; considered precancerous.

Cerebral Atrophy

Loss of neurons in the brain; may be focal (localized) or global (widespread).

Cardiac Hypertrophy

Thickening of heart muscle due to chronic excessive workload or pressure.

Cervical Metaplasia

Replacement of columnar with squamous epithelium in the cervix; risk factors include early sexual activity, multiple partners, HPV exposure, and smoking.

Sodium-Potassium Pump

Membrane protein that expels 3 Na⁺ and imports 2 K⁺, maintaining resting membrane potential.

Angiotensin II

Potent vasoconstrictor produced by ACE that raises blood pressure within the RAAS.

Antidiuretic Hormone (ADH)

Posterior-pituitary hormone that conserves body water and increases circulating volume during fluid loss.

Alarm Stage (General Adaptation Syndrome)

Initial stress-response phase that mobilizes body resources (e.g., catecholamines, cortisol).

Graves Disease Autoantibody (TSI)

IgG that mimics TSH, overstimulating the thyroid and causing hyperthyroidism.

Hyperthyroidism Symptoms

Clinical signs such as increased metabolic rate, agitation, restlessness, sweating, palpitations, and tremors.