Sec 31.3: Immune Responses

Question 1

What are the two types of immune responses?

Answer 1

Specific and nonspecific responses

Question 2

What are nonspecific responses?

Answer 2

They are immune responses that happen in the same way to every pathogen

Question 3

What are specific responses?

Answer 3

They are immune responses that occur on a cellular level and are slightly different for each pathogen

Question 4

What are the types of nonspecific responses?

Answer 4

Inflammation and Fever

Question 5

What are the types of specific responses?

Answer 5

Cellular immunity and Humoral Immunity

Question 6

What is inflammation?

Answer 6

It is a nonspecific response characterized by swelling, redness, pain, itching, and increased warmth at affected site

Question 7

When does inflammation occur?

Answer 7

When pathogen enters the body and body’s other tissues become damaged

Question 8

When does inflammation begin?

Answer 8

When mast cells or basophiles release chemicals called histamines in response to pathogen invasion

Question 9

What do histamines do?

Answer 9

They cause cells in blood vessels to spread out

Question 10

What happens after histamines are released?

Answer 10

Fluids move out of the blood vessel and into surrounding tissues, and white blood cells squeeze out of capillaries and move to site of infection, where they fight it off until swelling stops and tissue repair begins

Question 11

When does fever begin?

Answer 11

When mast cells or macrophages release chemicals that cause the hypothalamus to increase the body’s temperature

Question 12

What is low fever and what does it do?

Answer 12

Low fever is around 37.7 c, and it stimulates the production of interferons and increases the activity of white blood cells by increasing the rate at which they mature

Question 13

What does increasing the rate of white blood maturity do?

Answer 13

It accelerates the body’s fighting off of infection

Question 14

What is high fever and what does it do?

Answer 14

High fever is more than 39 c, and it causes the hypothalamus to be unable to regulate body temperature, and enzymes that control chemical reactions in the body stop functioning

Question 15

What are antigens?

Answer 15

They are protein markers on the surfaces of cells and viruses that help the immune system identify a foreign cell or virus

Question 16

How do specific responses lead to acquired immunity?

Answer 16

The body produces memory cells after fighting off a pathogen, which in turn destroy the pathogen if it reinvades the body

Question 17

What are memory cells?

Answer 17

They are specialized T and B cells that “remember” an antigen that has previously invaded the body and destroy it when it reinvades

Question 18

What is cellular immunity?

Answer 18

It is an immune response depending on T cells

Question 19

What are antigen-presenting cells?

Answer 19

They are phagocytes that display foreign antigens on their membrane

Question 20

What happens in cellular immunity?

Answer 20

Phagocyte engulfs foreign invader and displays the pathogen’s antigens on the membrane surface -> T cell binds to antigen-presenting cell, which releases proteins that activate the T cell -> activated T cell divides into activated T cells and memory T cells, which are reserved for the future -> Activated T cells bind to and destroy infected body cells

Question 21

What is humoral immunity?

Answer 21

It is an immune response depending on antibodies

Question 22

What happens in humoral immunity?

Answer 22

Pathogen binds to a B cell, which engulfs the pathogen and keeps a part of the antigen attached to its antibody -> T cell binds to trapped antigen fragment and stimulates B cells -> B cells divide into memory B cells and activated B cells -> Activated B cells produce antibodies that cause the pathogens to clump -> Phagocytes destroy pathogen clumps

Question 23

What is tissue rejection?

Answer 23

It occurs when the immune system of the recipient of a blood or organ donation makes antibodies against the protein markers on the donor’s tissue

Question 24

What are antigen receptors?

Answer 24

They are found on the surface of white blood cells, and they determine whether the immune system will attack or ignore a transplanted tissue

Question 25

How do antigen receptors determine the fate of the transplanted tissue?

Answer 25

If the transplanted tissue’s protein markers fit into white blood cells, they are considered foreign and attacked, but if they do not interact with white blood cells, they are not detected