Today I’m going to talk about: Poison

I’ve divided my presentation into two parts:

First I’d like to introduce the poison and second I’ll present of same

kinds of poison.

So, let’s start with introduce

Poison, any substance that produces disease conditions, tissue injury,

or otherwise interrupts natural life processes when in contact with or

absorbed into the body. Most poisons taken in sufficient quantity are

lethal. A poisonous substance may originate as a mineral, vegetable, or an

animal, and it may assume the form oof a solid, liquid, or gas. A poison,

depending on the type, may attack the surface of the body or, more

seriously, internal organs or the central nervous system.

Finally let’s consider: with kinds of poison

Poisons in humans are usually classified according to their effects as

corrosives, irritants, or narcotics; the last named are also known as

systemic or nerve poisons.

Corrosives include strong acids or alkalis that cause local tissue

destruction, externally or internally; that is, they “burn” the skin or the

lining of tthe stomach. Common or so-called household corrosive poisons

include hydrochloric acid, carbolic acid, bichloride of mercury, and

ammonia.

Irritants such as arsenic, mercury, iodine, and laxatives act directly

on the mucous membrane, causing gastrointestinal irritation or inflammation

accompanied by pain and vomiting; diluted corrosive ppoisons also have these

effects. Irritants include cumulative poisons, those substances that can be

absorbed gradually without apparent harm until they suddenly take effect.

Narcotic poisons act upon the central nervous system or upon important

organs such as the heart, liver, lungs, or kidneys until they affect the

respiratory and circulatory systems. These poisons can cause coma,

convulsions, or delirium. Narcotic poisons include alcohol, opium and its

derivatives, belladonna, turpentine, potassium cyanide, chloroform, and

strychnine. Also included in this category is one of the most dangerous

poisons known, botulin toxin, a potent bacterial toxin that is the cause of

acute food poisoning (see Botulism).

Blood poisoning, also bacterial in nature, is a condition that occurs

when virulent microorganisms invade the bloodstream through a wound or an

infection. Symptoms include chills, fever, prostration, and often

infections or secondary abscesses in various organs (see Septicemia). Most

poison gases also affect the bloodstream. Because these gases restrict the

body’s ability to absorb oxygen, they are often considered in a separate

category called asphyxiants, to which group ordinary carbon monoxide

belongs. Gas poisons, however, may also be corrosives or irritants