Principles of Medical Biology - Cellular Responses to Diseases

Flashcards covering key vocabulary and concepts related to cellular responses to diseases, inflammation, wound healing, and disturbances in blood flow.

Homeostasis

The steady state in which the internal condition of the cell is kept within physiological parameters.

Pathophysiological basis

The response of a cell to any change in its internal or external environment.

Adaptation

Reactions to injury collectively termed as…

Cell injury

A series of changes referred to when the capacity of the cell to adapt is exceeded.

Hypoxia

Reduced oxygen supply to tissues.

Main biochemical changes of cell injury

Release of oxygen-derived free radicals, increases in cytoplasmic calcium, depletion of ATP and defects of permeability of cell membranes.

Apoptosis

A regulated event designed for cell death in embryogenesis and physiological events; also termed programmed cell death.

Necrosis

Death of cells in living tissue, characterized by swelling of cells, death of cell organelles and release of mediators of the inflammatory response.

Autolysis

Death of cells post-mortem or after removal from the body at surgery.

Inflammation

Response of vascularised tissue to injury composed of a complex series of events that start with tissue injury and progress to vascular, chemical and systemic responses.

Granulomas

Collections of macrophages referred to as epithelioid cells, seen in granulomatous inflammation.

Caseating granulomas

Loss of cellular detail with cheese-like material centrally in granulomas.

Endothelial contraction

Increased vascular permeability mechanisms that are short-lived initial response.

Direct injury (e.g. burns)

Increased vascular permeability mechanisms that may be long-lived.

Damage by leucocytes

Increased vascular permeability mechanisms that cause damage and are long-lived later response.

New blood vessel formation

Increased vascular permeability mechanisms that are a long-lived response seen in early repair.

Outcomes of acute inflammation

Resolution, chronic inflammation, abscess formation, and healing

Cardinal signs of inflammation

Redness, heat, pain, swelling and loss of function.

Nonspecific systemic effects of inflammation

Raised erythrocyte rate (ESR), raised C-reactive protein (CRP), leucocytosis and fever.

Wound healing

Replacement of dead tissue by living cells or fibrous tissue.

Labile cells

Cells with great capacity for renewal.

Stable cells

Cells that are generally slow at regeneration but can renew nearly completely.

Permanent cells

Cells that lack regenerative capacity.

Adaptive responses of cells

Hypertrophy, hyperplasia, atrophy and metaplasia

Hypertrophy

Increase in cell size without cell replication.

Hyperplasia

Increase in cell numbers by cell division

Atrophy

Decrease in the size of cells or organs.

Metaplasia

Reversible replacement of one differentiated cell type with another type of differentiated cell.

Oedema

Abnormal accumulation of fluid in tissues.

Thrombosis

The pathological process by which blood clot forms within the uninterrupted vascular system

Embolus

A detached fragment of material – solid, liquid or gas – that is seen in a blood vessel distant from its site of origin or entry.

Infarction

Necrosis following ischaemia secondary to occlusion of arterial supply or venous drainage.

Shock

A condition of circulatory failure that results in hypoperfusion of vital organs.