Biology: Pathogens and defense

Pathogens

are harmful bacteria that infects the body.

Name types of pathogens

bacteria, virus, parasites, fungi

bacteria

single-celled organisms that lack a nucleus

virus

thread like organism that reproduces by taking over living cells.

fungus

A simple organism that can be a single cell or thread like

Protozoa

single cell with a nucleus

parasite

an organism that lives on or in a host and causes it harm

direct contact

bodily fluids, puss, saliva, blood, sexual intercourse

indirect contact

contaminated surfaces, food, animals, air.

How does indirect contact work?

Sick people can contaminate thing after they touch it.

first lines of defense

Skin, Mucus, oils, Stomach acid, nose hair

How does skin at as a defense

Skin acts as a barrier that prevent bacteria from getting inside the body.

How does oil act as a defense

the oils on the skin is slightly acidic which prevents bacteria from living on the skin.

How does stomach acid act as a defense

the stomach acids kill bacteria and it has a mucus lining.

What type of acid is in the stomach and what lines the inner part.

the stomach acid is hydrochloric acid, and the stomach is lined with mucus.