Chapter 48 Immune System

Question 1

What are the two main types of immunity? How are they different?

Answer 1

Innate Immunity: Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens. Nonspecific
Adaptive Immunity: the ability to recognize and remember specific antigens and mount an attack on them

Question 2

Describe the immune system of sponges/cnidarians:

Answer 2

Uses amoebocytes (phagocytic cells). Might be referred to as coelomocytes (in coelom) or hemocytes (in hemolymph). They engulf things that aren’t supposed to be there.
Even a sponge can recognize itself, as can most animals on some level.

Question 3

Describe the annelid immune system:

Answer 3

basophilic amoebocytes (engulf things)
acidophilic granulocytes: cytoplasmic granulues (long term storage vesicles near the cellular membrane) are ready to be discharged.
They have antimicrobial properties and send a signal warning to other cells.

Question 4

What are amoebocytes ? What are coelocytes? what are hemocytes?

Answer 4

Amoebocytes: phagocytic cells
Coelocytes: amoebocytes in coelom
Hemocytes: amoebocytes in hemolymph

Question 5

Describe the anthropod immune system:

Answer 5

Barrier defense: chitinous exoskeleton is impervious to bacteria and other things trying to get into the body. However, insects can still get injured so also have internal mechanisms.
- Phagocytic cells
- Hemocytes (in hemolymph, engulf non-self cell)
- Antimicrobial compounds
Toll receptors: sensitive to particular compounds, and activate a signal transduction pathway that generates antimicrobial peptides and releases cytokines.
also have lysozyme

Question 6

What are lysozymes?

Answer 6

an enzyme secreted from the digestive tract of insects, used to kill invaders

Question 7

what are non-specific defenses?

Answer 7

bodily defenses that protect a person against all micro-organisms , regardless of prior exposure

Question 8

What is the first line of defense for humans and most animals?

Answer 8

Epithelial Tissue: our first and biggest line of defense. Skin, lining of respiratory tract and digestive tract.

Question 9

How does skin act as a barrier?

Answer 9

Antimicrobial compounds are made.
Physical and chemical barrier
Skin acidity (skin secretions).
Washing action secretions
Antimicrobial proteins
Lysozyme from skin secretions
Acidity of the stomach kills most things that you might digest.
Tight junction of epithelial cells prevents entry.
If this barrier is broken, we should be concerned about both water loss and infection.

Question 10

what are neutrophils? how do they work?

Answer 10

60-70% white blood cells, most common ones, if there is infection they will multiply, engulf stuff that are not self, then die couple days after

Question 11

what are basophils?

Answer 11

0.5% of leukocytes, largest, important in allergies, acute/chronic, degranulate and initiate inflammation

Question 12

what are eosinophils?

Answer 12

2-5% of white cells, granulocytes, release toxins around lymphatic system and ovaries, for multicellular threats, don’t divide, mainly in tissue

Question 13

what are monocytes?

Answer 13

5% of white cells, migrate into into tissue, develop into macrophage, kills microbes, engulfs them

Question 14

what are macrophages?

Answer 14

amoeboid cells that roam connective tissue and engulf foreign particles and debris of dead cells, part of the innate immune system and adaptive immune system

Question 15

how do macrophages work?

Answer 15

they have receptors that recognize certain molecular patterns that are unique to pathogens, such as bacterial cell walls or viral RNA. They engulf the pathogen, and destroy it by enzymes and toxic substances.

Question 16

how does an inflammatory response work?

Answer 16

-damage occurs and cytokines are released
-bleeding occurs, platelets begin clotting process and attach to fibrinogens
-cells at the site release cytokines, macrophage engulf things
-most cells degranulate releasing histamines
neutrophils phagocytize foreign material (engulfing stuff in huge numbers)
-monocytes arrive and mature into macrophages, more cytokines, helps get rid of all invaders and tissue repair

Question 17

what are NK cells?

Answer 17

natural killer cells, attract virus-infected cells. basically kills self/destruct, have the ability to recognize cells immediately, mature in bone marrow, large granular lymphocytes (LGL)

Question 18

how do NK cells work?

Answer 18

release NO2 that react with death receptors and result in apoptosis.

Question 19

how do inflammatory responses help fight an infection?

Answer 19

induces inflammation, release histamines that cause blood vessels to constrict and increase the blood flow into tissue.

Question 20

what is a systematic inflammatory response?

Answer 20

severe infection or tissue damage, the number of leukocytes goes way up in a short time, vasodilation all over, not enough blood, can result in fever (resets the bodies natural thermostat), can result in sepsis.

Question 21

how do B cells develop?

Answer 21

cells are manufactured in the bone marrow (mature in bursa) that create antibodies for isolating and destroying invading bacteria and viruses.

Question 22

how do T cells develop?

Answer 22

cells created in the thymus that produce substances that attack infected cells in the body. Only have one antigen receptor (but lots of it) and are therefore very specific.

Question 23

what is an antigen?

Answer 23

little pieces of proteins

Question 24

how are B and T cells different?

Answer 24

B cells produce antibodies that specifically recognize and bind to antigens.T cells are involved in cell-mediated immunity which means they directly recognize and attack cells that are infected or abnormal. B cells recognize antigens on the surface through B-cell receptors while T cells recognize antigens that are presented on the surface of other cells in complex with MHC molecules.

Question 25

what are MHC molecules?

Answer 25

major histocompatibility complex, antigens bind to these, and they present the antigens in the body

Question 26

what are class 1 MHC molecules?

Answer 26

found in all nucleated body cells, bind to cytotoxic T-cells

Question 27

what are class 2 MHC molecules?

Answer 27

macrophages, B-cells, activated T-cells and thymus cells. Bind to helper T-cells.

Question 28

what are antibodies? how do they work?

Answer 28

enhance phagocytosis: increased by neutralization of toxins. Neutralize toxins: can be done by binding to it. makes it easier for a macrophage to engulf it. Can cause things to clump up. Can cause soluble antigens to precipitate out of solutions. Promote cell lysis

Question 29

what is humoral immunity?

Answer 29

specific immunity produced by B cells that produce antibodies that circulate in body fluids. Mainly effective against bacteria, viruses, and toxins in bodily fluids.

Question 30

what is cell-mediated immunity?

Answer 30

mainly effective against infected cells and cancerous cells. More so T-cells

Question 31

how are T-cells involved in humoral immunity?

Answer 31

when pathogen is in body the helper t-cells will get activated by the exposure to the antigen which then activates more b-cells to come and help.

Question 32

Why is secondary immune response quicker and longer lasting?

Answer 32

Because there are memory b-cells and memory t-cells that are ready to go. stronger response to the antigens.

Question 33

what is clonal selection?

Answer 33

when a B-cell replicates, it gives rise to plasma B-cells which actively fight, and memory B-cells, which remember specific antigen. When cytotoxic T-cells divide, they do the same thing

Question 34

what is the difference between active and passive immunity? Give examples

Answer 34

Active immunity is secondary immune response, better, stronger. The body produces its own antibodies against disease-causing antigens. (E.g persons resistance to strep throat due to a previous infection).
Passive immunity is short lived, antibodies are given to you that you didn’t make. (E.g. mother has antibodies in breast milk when feeding child, certain drugs, and in the womb)

Question 35

How do ABO blood groups get inherited?

Answer 35

A an B refer to a specific carbohydrate on blood cells. An ABO mismatch is recognized immediately.
A, or B, or AB, or O (A = one allele(I^Ai) , B = another allele(I^Bi), AB = both(I^AI^B), O = neither). An example of codominance. Type A is the universal recipient and type O is universal donor

Question 36

how does ABO blood group affect tissue plantation?

Answer 36

if someone is given the wrong type of blood it can result in death.

Question 37

How are allergies related to the immune system?

Answer 37

inappropriate reaction to an antigen (allergen). IgE antibodies: produced by B-cells in response to exposure to an allergen. Bind to mast cells and basophils. Causes them to granulate and they release histamine.

Question 38

What is anaphylactic shock?

Answer 38

severe allergic reaction that causes respiratory distress due to swelling of the upper airways.