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nutrition

(Encyclopedia)nutrition, study of the materials that nourish an organism and of the manner in which the separate components are used for maintenance, repair, growth, and reproduction. Nutrition is achieved in vario...

immunity

(Encyclopedia)immunity, ability of an organism to resist disease by identifying and destroying foreign substances or organisms. Although all animals have some immune capabilities, little is known about nonmammalian...

dysentery

(Encyclopedia)dysentery dĭsˈəntĕrˌē [key], inflammation of the intestine characterized by the frequent passage of feces, usually with blood and mucus. The two most common causes of dysentery are infection wit...

immunology

(Encyclopedia)immunology, branch of medicine that studies the response of organisms to foreign substances, e.g., viruses, bacteria, and bacterial toxins (see immunity). Immunologists study the tissues and organs of...

mercury poisoning

(Encyclopedia)mercury poisoning, tissue damage resulting from exposure to more than trace amounts of the element mercury or its compounds. Elemental mercury (the silver liquid familiar from thermometers) is the mos...

parasite

(Encyclopedia)parasite, plant or animal that at some stage of its existence obtains its nourishment from another living organism called the host. Parasites may or may not harm the host, but they never benefit it. T...

silkworm

(Encyclopedia)silkworm, name for the larva of various species of moths, indigenous to Asia and Africa but now domesticated and raised for silk production throughout most of the temperate zone. The culture of silkwo...

heart, in anatomy

(Encyclopedia)CE5 Cross section of heart, with arrows indicating direction of blood flow heart, muscular organ that pumps blood to all parts of the body. The rhythmic beating of the heart is a ceaseless activit...

inoculation

(Encyclopedia)inoculation, in medicine, introduction of a preparation into the tissues or fluids of the body for the purpose of preventing or curing certain diseases. The preparation is usually a weakened culture o...

insomnia

(Encyclopedia)insomnia, abnormal wakefulness or inability to sleep. The condition may result from illness or physical discomfort, or it may be caused by stimulants such as coffee or drugs. However, frequently some ...