Does not allow the body to function normally

Can affect individual organs or an entire body system

Divided into two groups –Infectious and Non-infectious

An infectious disease is a disease that is caused by the presence of a living thing within the body.

When you have an infectious disease, pathogens have gotten inside your body & caused harm.

BacteriaVirusesFungiProtist

Pathogens need food & a place to live & reproduce.

Sometimes a human body is a suitable place for a pathogen to meet its needs.

Pathogens can spread through contact with………

Another person

Contaminated objects

Animal bite

Environment

It works by damaging individual cells within the organs

In some cases it attacks an entire body system

distinguishing (telling the difference) between the different kinds of pathogens

Reacting to each kind according to its type

The body has 3 lines of defense

Skin-Physical & chemical barrier

Mucous & Cilia-trap & remove most pathogens

Sneezing & Coughing

Chemicals in saliva & stomach acid kill pathogens

o Triggers inflammatory response.o Fluid & white blood cells leak from blood vessels

into nearby tissues.o White blood cells then fight the pathogens. These

wbc’s are called phagocytes. o Phagocytes engulf & destroy pathogens.o During the inflammatory process, the affected

area becomes red, swollen, & warm.o Fever may also occur

The cells of the immune system can distinguish between different kinds of pathogens.

The immune system cells react to each kind of pathogen with a defense targeted specifically at the pathogen.

White blood cells that target specific pathogens are called lymphocytes.

Are diseases that are not caused by pathogens in the body.

Cardiovascular disease, diabetes, & cancer are examples of noninfectious diseases.

Is a disorder in which the immune system is overly sensitive to a foreign substance- something not normally found in the body.

An allergy develops in response to various foreign substances that set off a series of reactions in the body.

An allergen is any substance that causes an allergy.

People may be allergic to pollen, dust, molds, some foods, or even some medicines.

Your pancreas produces insulin, a chemical that enables body cells to take in glucose from the blood & use it for energy.

If you have diabetes, your pancreas fails to produce enough insulin, or the body’s cell fail to properly use insulin.

As a result, a person with diabetes has high levels of glucose in the blood and may even excrete glucose in urine.

People with diabetes may lose weight, feel weak, & always be hungry.

Is a disease in which cells multiply uncontrollably, over & over, destroying healthy tissue in the process.

As cancerous cells divide over & over, they often form abnormal tissue masses called tumors.

A carcinogen is a substance or factor in the environment that can cause cancer.

Surgery, drugs, & radiation are all used to treat cancer.

People can reduce their risk of cancer by avoiding carcinogens. They can increase their chance of surviving cancer by having regular medical checkups.

•Affects the lungs and the airways that deliver air to the lungs

•Causes periodic attacks of wheezing and difficulty breathing

Occur when the airways become inflamed in response to a stimulus, such as dust, mold, pets, exercise, or cold weather

Some attacks start for no apparent reason