Immune System

Question 1

The Skin

Answer 1

physical barrier of dead skin. It contains chemicals (acids and oils) that inhibit the growth of micro-organism

Question 2

immune system

Answer 2

• Body’s first line of defense against intruders.

- It consists of several nonspecific obstacles to infections

Question 3

Sweat, saliva and tear

Answer 3

all contain lysozomes which are enzymes that attack the cell wall of bacteria

Question 4

Stomach’s gastric juices

Answer 4

kill most bacteria swallowed with food

Question 5

cilia

Answer 5

hair like projections on cells lining the respiratory system that filter incoming air cells

Question 6

Nonspecific defensive cells

Answer 6

neutrophils, monocytes, macrophages, natural killer cells

Question 7

Antimicrobial proteins

Answer 7

attack microorganisms directly or impede reproduction. They include interferons and complement. They also include histamine-proteins which causes blood vessels to dilate thus allowing blood and phagocytes (white blood cells) to enter the infected area

Question 8

The inflammatory response

Answer 8

there is an increase in the temperature of the infected area. This is caused by a group of proteins called pyroproteins. An increase in temperature impedes the reproduction of the micro-organisms. The inflammatory response can be localized or systemic (this produces a fever)

Question 9

Immune system

Answer 9

recognizes and defends against specific kinds of invasive microbes and cancer cell

Question 10

Antigen-

Answer 10

a molecule that elicits an immune response

Question 11

Pathogens

Answer 11

a disease causing agent (include viruses, bacteria, fungi, protozoa and parasitic worms.)

Question 12

Antibody

Answer 12

a plasma protein that attaches to one particular kinds of antigen and helps counter its effects

Question 13

Portal of exit

Answer 13

vehicle by which a pathogen leaves the body of an infected host

Question 14

Portal of entry

Answer 14

vehicle by which a pathogen enters the body of an un-infected host

Question 15

Infective dosage

Answer 15

the concentration of pathogen needed to cause an infection

Question 16

Lymphocytes

Answer 16

white blood cells
–2 types:
•B lymphocytes
•T lymphocytes (3 types)
–T-helper
–T-killer
–T-suppressor

Question 17

Immune response

Answer 17

• Macrophage engulfs the pathogens and displays the pathogen’s antigenic determinants on its surface.
• This stimulates the productions of T helper cells.
• T-helper cells begin to secrete the protein, lymphokines

Question 18

HUMORAL IMMUNITY

Answer 18

As the levels of lymphokines increase, this activates the productions of B cells and T killer cells.
•The B cells begin to secrete antibodies which are specific for the pathogen. These antibodies will neutralize free floating pathogen.

Question 19

CELL-MEDIATED IMMUNITY

Answer 19

T killer cells begin to destroy infected cells
As a result of this process, there are B and T memory cells circulating in the blood stream which will cause a quicker response if you are infected with the same pathogen.
•Immunological failures cause several diseases

Question 20

Autoimmune diseases

Answer 20

results when the immune system turns against the body’s own molecules
–Example: insulin-dependent diabetes, rheumatoid arthritis, systemic lupus, and multiple sclerosis

Question 21

Immunodeficiency diseases

Answer 21

diseases that are caused by the lack of one or more of the components of the immune system. As a result, the individual are susceptible to infections that would ordinarily not cause a problem
–Example: SCID (severe combined immunodeficiency-where both T and B cell are absence or inactive.

Question 22

AIDS

Answer 22

acquired immune deficiency syndrome-where the T helper cells are destroyed

Question 23

Allergies

Answer 23

abnormal sensitivities to antigen. They can range from seasonal problems to severe, life threatening responses (anaphylactic shock)

Question 24

Immunity

Answer 24

mmunity-resistance to specific invaders
•Two types of immunity
–Activity immunity-when an antigen enters the body naturally or artificially, the body is stimulated to produce antibodies in its own defense

Question 25

Passive immunity

Answer 25

antibodies are made somewhere else and are injected or passed to another individual.

Question 26

Specific immune response

Answer 26

This is activated only when the nonspecific defense mechanisms have failed.