Pathology and Inflammation

In lymph nodes, what do you check for?

Induration (hardening), tenderness, mobility/fixation, and whether one or more nodes are involved.

Localized vs. generalized

Localized means one area; generalized means widespread or more than one area.

Erythema

Abnormal redness caused by thin epithelium or inflammation.

Coalescing

Parts growing together as a whole.

Macule vs. patch

Macule is flat, different color, < 1 cm. Patch is flat, > 1 cm, different color or texture.

Vesicle

An elevated lesion filled with clear fluid and < ½ cm.

Pustules

Raised lesions containing pus (white blood cells, debris, and microorganisms).

Plaque

Slightly raised, broad, flat top, "pasted on."

Sessile base

A broad base attached directly to tissue.

Pedunculated base

Attached by a narrow stalk.

Exophytic vs. endophytic

Exophytic grows outward; endophytic grows into the tissue.

Etiology

The cause of a disease.

Pathogenesis

The manner in which a disease progresses.

Idiopathic

Unknown cause of disease.

Iatrogenic

Caused by a medical procedure.

Exocrine system

Glands releasing products through ducts (sweat, sebaceous, salivary, GI, respiratory); body's first line of defense.

Integumentary system components

Skin, hair, nails, sweat, and sebaceous glands.

Factors affecting the immune system

Age, lifestyle, stress, environment, genetic factors, and immune system dysfunction.

Pathogenesis of disease process

Includes incubation period, active process, and latent period.

Incubation period

The period in which the disease is developing.

Latent period

Time during development with no manifestation but detectable via lab tests and radiographs.

Apoptosis

Programmed cell death.

Body adaptation to abnormal conditions

Cells adapt, injure, or die; adaptive changes continue until stimulus is removed.

Atrophy

Cells decrease in size and function due to reduced demand, hormones, lack of nutrients, aging, or disease.

Hypertrophy

Individual cells become larger, increasing organ size due to increased demand or hormones.

Hyperplasia

Increase in number of cells causing enlargement due to chronic injury, hormones, or cell death.

Metaplasia

Conversion of one cell type into another; reversible if stimulus is removed.

Dysplasia

Abnormal cells develop from normal cells with changes in size, shape, and nuclei; may progress to neoplasia.

Necrosis

Pathologic cell death when unable to adapt. Types: caseous, coagulative, and liquefactive.

Cardinal signs of acute inflammation

Redness (rubor), heat (calor), swelling (tumor), pain (dolor), and loss of function (functio laesa).

Healing process of an injury

Restores structure and function through regeneration, fibrous repair, scar formation, angiogenesis, and epithelization.

Vascular response following constriction

Vasodilation increases blood flow and vascular permeability.

Margination process

WBCs move to vessel lining (margination), pavementing (stick and stack), and emigration (move out).

Chemotaxis inhibitor

Nicotine is a powerful inhibitor of chemotaxis.

Opsonization

The process of marking foreign material for phagocytosis.

End result of unresolved acute inflammation

An abscess forms where PMNs, bacteria, and debris collect into localized pus.

Process of acute inflammation

Initiation, amplification, destruction, and termination.

Polymorphonuclear neutrophils (PMNs)

Granulocytes, first leukocytes to arrive, fighting bacterial and fungal infections.

Eosinophil

Granulocyte that fights parasitic infections and is involved in allergic reactions.

Monocytes to macrophages locations

Liver = Kupffer cells; connective tissue = histiocytes; brain = microglial cells.

LPS (Lipopolysaccharide)

Component of Gram-negative cell walls released upon destruction; activates macrophages, endothelial cells, and leukocytes.

Platelet-activating factor (PAF)

Causes platelet aggregation; releases serotonin to increase vascular permeability.

Chemokines

Very strong chemotactic agents that attract leukocytes.

Membrane attack complex (MAC)

Punches holes in cell membranes of microbes.

Immunoglobulins

Antibodies produced by the immune system that can act as opsonins.

Kinin system

Forms bradykinin, which causes vasodilation, pain, and smooth muscle contraction.

Fistula

Abnormal tract or connection opening to a body surface or structure, allowing pus to drain.

Cellulitis

Connective tissue inflammation caused by Staph and Strep bacteria.

Bacteremia

Presence of bacteria in the blood; can turn into septicemia.

Septicemia

Bacteremia resulting in clinically observable illness.

Regeneration

Formation of new functional tissue restoring structure and function.

Angiogenesis

Formation of new blood vessels.

Primary vs. secondary intention healing

Primary: clean margins brought together. Secondary: significant tissue lost, heals from base.

Keloid

Excessive scar tissue resulting from injury healing.