Immune System (Part of Human Body Science)

Question 1

What is the function of the Immune System?

Answer 1

The Immune System uses two ways of doing things in order to protect the body from foreign invasion.

Question 2

What are the two systems that the Immune System uses to perform?

Answer 2

1. The innate = nonspecific defense system

2. The adaptive = specific defense system

Question 3

The innate nonspecific defense system

Immune System

Answer 3

The innate nonspecific defense system is like the low key soldier that is always prepared for foreign invasion.
The “1st line of defense” = your external body membranes: skin, mucosa, digestive enzymes.
The “2nd line of defense” = whenever first has been penetrated results in inflammation, fever, phagocytosis, natural killer cells, interferons, chemotaxis, and release of cytokines

Question 4

The adaptive specific defense system (Immune System)

Answer 4

This system is more like the sniper soldier equipped with high-tech weapons to attack particular foreign substances.
It’s the “3rd line of defense” which will take more time to perform in the body.

Question 5

How do mild to moderate fevers benefit the body?

Answer 5

The benefit is the body kills pathogens that grow better at low body temperatures.

Question 6

Inflammation results because:

Answer 6

Inflammation occurs as a response to irritating chemicals, heat, trauma, or infection by pathogens.

Question 7

What are the four cardinal signs of inflammation?

Answer 7

• Redness
• Heat
• Swelling
• Pain

Question 8

Natural Killer Cells AKA NK Cells

Answer 8

These cells produce perforins = pore-forming proteins that target cancer and virus cells. The perforins cause these invaders to lyse or rupture.

Question 9

Interferons

Answer 9

Interferons are the body’s response to a viral infection and prevent replication of the virus after 7 – 10 days.
They also activate and macrophages and NK cells.

Question 10

Chemotaxis

Answer 10

Chemotaxis is the method by which leukocytes (white blood cells) respond to damaged body tissues. This is accomplished in part through cytokines; which are chemical messengers that are released by damaged tissues.

Question 11

Diapedesis

Answer 11

Diapedesis is the process of white blood cells squeezing through capillary slits in response to cytokines. The process is facilitated by cellular adhesion molecules (CAMs) guiding the white blood cells to the site of damage or infection.

Question 12

“3rd line of defense”

Answer 12

The adaptive response system uses humoral, or antibody-mediated and cell-mediated weapons.

Question 13

Antibody-Mediated Weapon

Answer 13

Antibodies are produced that are specific for the invading antigen.

Question 14

Antibodies

Answer 14

The antigen binds to B cells which are types of lymphocytes or small leukocytes. When the antigen binds to the B cells it activates the B cells to produce antibodies. Once the body has produced antibodies agianst a pathogen; it is able to recognize it in the future and destroy it more effectively.

Question 15

What do vaccines do?

Answer 15

In active immunity, an individual recieves a vaccine that stimulated an actual infection by a pathogen, stimulating the body to produce more antibodies for future protection.

Question 16

Passive Immunity

Answer 16

In passive immunity, an individual does not produce their own antibodies, instead recieves them from another source.
Example:
Mother to infant through breastmilk

Question 17

Cell-mediated Immunity

Answer 17

T cells are primarily responsible for recognizing foreign cells. A T cell is a lymphocyte that triggers the action of other lymphocytes.

Question 18

T cells

Answer 18

In a three-step process, T cells activate other lymphocytes:
#1 Macrophages capture the foreign cell
#2 A T-helper cell binds to it and secretes a cytokine that signals the cytoxic T cell
#3  The cytoxic T cell responds through chemotaxis and actively destroys the foreign cell