METASTASIS

The term metastasis connotes the developement of secondary implants discontinuous with the primary tumor,possibly in the remote tissues.However not all tissues have the ability to metastasize.The notable exceptions are basal cell carcinoma of the skin and most primary tumors of the central nervous system.Extremely small cancers are known to metastasize and large ugly lession may not have spread.

SHOCK..

Shock often loosely called vascular collapse.Shock constitutes of widespread hypoperfusion of cells and tissues due to reduction in the blood volume or cardiac output.
Shock may be induced by any insult to the body,such as hemorrhage,severe trauma or burns,extensive myocardial infarction,or uncontrolled bacterial sepsis.

Types Of Shock

1.Cadiogenic shock.
2.Hypvolemic shock.
3.Septic shock.
4.Neurogenic shock.

SMALLPOX VIRUS.

Small pox virus,is the agent of smallpox the only disease that has been eradicated from the face of the earth.Eradication is due to the vaccine.The virus contain DNA-depandant RNA polymeraser.This enzyme is required because replication occur in cytoplasm.It has single stable serotype.

GRANULOMATOUS INFLAMATION......

Granulomatous inflamation is adistinctive pattern of choronic inflamation charecterized by accumulation of modified macrophages(epitheloid cells)and initiated by a variety of infectious and noninfectious agent.Large giant cells are often found at the periphery or sometimes in the centre of granuloma.
Examples;tuberculosis,leprosy,cat scratch disease,syphilis.

Chronic Inflammation Histologic Features

In contrast to acute inflammation, which is manifested by vascular changes, edema, and largely neutrophilic infiltration, chronic inflammation is characterized by:

1.Infiltration with mononuclear cells, which include macrophages, lymphocytes, and plasma cells, a reflection of persistent reaction to injury.

2.Tissue destruction, largely induced by the inflammatory cells.

3.Attempts at healing by connective tissue replacement of damaged tissue, accomplished by proliferation of small blood vessels and fibrosis.

Causes of Chronic Inflammation

Chronic Inflammation arises under the following settings:

1.Persistent infections by certain microorganisms, such as tubercle bacilli, Treponema pallidum and certain fungi.

2.Prolonged exposure to potentially toxic agents, either exogenous or endogenous.

3.Autoimmunity: Under certain conditions, immune reactions are set up against the individual's own tissues, leading to autoimmune diseases.

Chronic Inflammation

Chronic Inflammation is considered to be inflammation of prolonged duration in which active inflammation, tissue destruction, and attempts at repair are proceeding simultaneously.

Chronic Inflammation frequently begins insidiously, as a low-grade, smoldering, often asymptomatic response. This latter type of chronic inflammation includes some of the most common and disabling human diseases, such as rheumatoid arthritis. atherosclerosis, tuberculosis, and chronic lung diseases.