Diseases and Associated Part of Human Body, Science Study Notes, Material

Diseases and Associated Part of the Human Body:

A disease is a state in which, the body or organs of the body show variation. Such changes are called symptoms. Therefore, symptoms indicate the presence of disease. 

Acute diseases

Diseases which last for a short period is called acute disease. For example, common cold, fever, eye infections, pain, etc.

Chronic diseases

Diseases that last for a long time are called chronic diseases. For example, Kidney disease, heart disease, respiratory disease, etc. Also, it causes prolonged weakness in the body. For example, if a person suffers from tuberculosis, the person can face weight loss and a long period of weakness providing bad health.

The different means by which infectious diseases spread are:

(a) Through air: They are also called air-borne diseases. The air carries bacteria, virus and the diseases that can be caused are the common cold, influenza, tuberculosis etc.
(b) Through food and water: When one eats/drinks contaminated food/water, that contains bacteria, viruses, worms etc. it can cause diseases like cholera typhoid, and hepatitis.
(c) Through contact: Many diseases are spread by contact of an infected person with a healthy person. For example, fungal infections, skin diseases, scabies etc.
(d) By sexual contact: Many diseases can be transmitted, for example, syphilis, and AIDS.
(e) By body fluids: Fluids like blood, semen, and mother’s milk, when infected,
can also cause diseases. For example AIDS.
(f) Vectors: The organism that spreads disease by carrying pathogens from one place to another is called a vector. For example, mosquitoes are vectors that carry pathogens like protozoa.