AP Chp 17 Immunity

Question 1

Types of Body defenses against disease

Answer 1

Non specific defenses - Effective against any harmful agent.

Specific defenses - Effective against a certain agent (specific pathogen)

Question 2

Factors involved in infection

Answer 2

Portal of entry - Respiratory tract most common, digestive system, urinary and reproductive systems.
Virulence - organisms power to overcome host defenses. (aggressiveness) and ability to produce toxins that damage the body.
The dose (number) of pathogens that invade the body.
Individuals condition (predisposition) to infection.

Question 3

Non specific immunity

1st line of defense

Answer 3

Successive lines of defenses.
1st line of defense are barriers: Intact skin
Mucous membranes.
Body secretions.
Reflexes e.g. coughing, sneezing.

Specific immunity is the final line of defense.

Question 4

Non specific immunity

2nd line of defense

Answer 4

Phagocytosis of the foreign material by WBC’s Neutrophils (granular leukocytes)and Macrophages (monocytes).
Natural killer cells (NK) - recognize cells with abnormal membranes and kill them on contact.
Inflammation - Heat, swelling, redness and pain.
Fever - Increased body temp, inhibits organisms ability to multiply.
Interferon - Certain cells infected with virus release substance that prevents nearby cells from producing more viruses.
Complement - Bind to foreign cells, destroy cells by punching holes in membrane, promote inflammation, and attract phagocytes to inflamed area.

Question 5

Specific Immunity

Answer 5

Power to overcome specific disease agent
Antigens - Foreign substances that are non self enter body and induce immune response of certain lymphocytes T-cells and B-cells.

Question 6

T-cells

Answer 6

Originate in red bone marrow
Mature in thymus
Provide cell mediated immunity
Types:
Cytoxic Tcells- Directly destroy abnormal cells.
Helper Tcells- Immune system manager cells.
Regulatory Tcells- suppress immune response to prevent over activity.
Memory Tcells- remember antigens for rapid response if contacted again.
T-cells are activated by APC’s (antigen presenting cells) Macrophages and Dendritic cells that remove part of antigen and present it to helper cells so immune system knows what to do.

Question 7

B-cells

Answer 7

Originate and mature in the red bone marrow.
Produce antibodies (Y shaped proteins)
Provide humoral immunity (antibodies from the original antigen).
Plasma cells - secrete antibodies due to exposure to antigen. (Memory B-cells).

Question 8

Types of immunity

Answer 8

Active-Natural= direct exposure to pathogen produces antibodies.

Active-Artificial= vaccination begins antibody production.

Passive-Natural= antibodies passed from mother to fetus.

Passive-Artificial= antibodies in form of Immunoglobulins are admin’d to pt to protect from infection until body produces antibodies.

Question 9

Types of vaccines

Answer 9

Live - nonvirulent for humans, laboratory weakened.
Attenuated - Weakened organism for use.
Toxoid - toxin altered with heat or chemicals to reduce harmfulness.

Question 10

Boosters

Answer 10

Active immunity does not always last a lifetime.
Repeated inoculations (booster shots) help maintain high titer of antibodies in the blood.