First Line of Defense

Question 1

What does the body maintain by eliminating pathogens that can destroy your cells?

Answer 1

Homeostasis

Question 2

What is the First line of defense against pathogens?

Answer 2

Barriers such as the

1. skin,
2. breathing passages,
3. mouth, and stomach

trap and kill most pathogens with which you come into contact

Question 3

1. Skin

How does skin fight against pathogens?

Answer 3

o When pathogens land on the skin, they are exposed to destructive chemicals in oil and sweat.
o If these chemicals don’t kill them, the pathogens may fall off with dead skin cells.
o If the pathogens manage to stay on the skin, they must get through the tightly packed dead cells that form a barrier on top of living skin cells.
o Most pathogens get through the skin only when it is cut. Scabs form over cuts so rapidly that the period in which pathogens can enter the body in this way is very short.

Question 4

2.Breathing Passages

How do breathing passages fight against pathogens?

Answer 4

o You can inhale pathogens when you breathe in.
o The nose, pharynx, trachea, and bronchi, however, contain mucus and cilia. Together, the mucus and cilia trap and remove most of the pathogens that enter the respiratory system.
o Also, irritation by pathogens may make you sneeze or cough. Both actions force the pathogens out of your body

Question 5

3. Mouth and Stomach ?

Answer 5

o Some pathogens are found in foods, even if the foods are handled safely.
o The saliva in your mouth contains destructive chemicals and your stomach produces acid. Most pathogens that you swallow are destroyed by saliva or stomach acid

Question 6

What is the Second Line of Defense against pathogens?

Answer 6

The Inflammatory Response

Question 7

What is the Inflammatory Response?

Answer 7

pathogens sometimes get into your body and begin to damage cells. When body cells are damaged, they release chemicals that trigger the inflammatory response

Question 8

What happens in the inflammatory response?

Answer 8

fluid and certain types of white blood cells leak from blood vessels into nearby tissues. The white blood cells then fight the pathogens. Because the inflammatory response is the same no matter what the pathogen, it is sometimes called the body’s general defense

Question 9

White Blood Cells

Answer 9

o All white blood cells are disease fighters, but there are different types, each with its own particular function.
o The kinds involved in the inflammatory response are called phagocytes.

Question 10

phagocyte

Answer 10

A phagocyte is a white blood cell that engulfs (eats) pathogens and destroys them by breaking them down.

Question 11

Inflammation

Answer 11

o During the inflammatory response, blood vessels widen in the area affected by the pathogens.
o This enlargement increases the flow of blood to the area. The enlarged blood vessels—and the fluid that leaks out of them—make the affected area red and swollen.
o If you touch the swollen area, it will feel slightly warmer than normal.
o Inflammation comes from a Latin word meaning “to set on fire.”

Question 12

Fever

Answer 12

o In some cases, chemicals produced during the inflammatory response cause a fever, raising your body temperature above its normal temperature of 37° Celsius.
o Although fever makes you feel bad, it actually may help your body fight the infection. Some pathogens may not grow and reproduce well at higher temperatures.