Lecture 7 - Immune system

Question 1

What is the blood comprised of

Answer 1

Erythrocytes, Leukocytes and Platelets (thrombocytes)

Question 2

What does plasma do

Answer 2

Plasma carries blood cells, proteins, nutrients, metabolic products and waste, and other
molecules being transported around the body.

Question 3

What is Haematocrit

Answer 3

The percentage of blood volume
that is erythrocytes
Men - 45%
Women 42%

Question 4

What is Bulk flow

Answer 4

Rapid flow of blood throughout the
body

Question 5

What are some features of RBCs

Answer 5

Biconcave
Flexible membrane
Large SA
No mitochondira
No DNA

Question 6

Where are RBCs produced

Answer 6

Bone Marrow

Question 7

What are Reticulocytes

Answer 7

Young erythrocytes in bone marrow contain a few
ribosomes which produce a web-like appearance
(reticular) when stained

Question 8

What is the breakdown product of haemoglobin

Answer 8

Bilirubin - Yellow colour

Question 9

Why is there a decrease in ability of the blood to carry oxygen in Anemia

Answer 9

1) a decrease in the total number of RBCs
2) Low haemoglobin per RBC
3) a combination of both

Question 10

How are RBCs replaced

Answer 10

erythropoietin (a hormone from the
kidneys) to stimulate erythropoiesis

Question 11

What s Haemostasis

Answer 11

The stoppage of bleeding

Question 12

What is the response to a severed blood vessel

Answer 12

Constriction - Slows blood flow to the area
Presses Endothelial surfaces together inducing a “stickiness”“gluing” them together

Question 13

What is platelet activation

Answer 13

Platelets release ADP and serotonin that induce changes
in metabolism, shape and surface protein expression on platelets (as well as releasing actin and myosin to allow contraction)

Question 14

What does EDTA do

Answer 14

A chemical
compound
that prevents
clotting by
“mopping up”
calcium

Question 15

What does heparin do

Answer 15

prevents clotting by
activating a plasma
protein called
antithrombin III (found in endothelial cells)

Question 16

What is the clinical testing significance for EDTA (Ethylene-diamine-tetra-acetic acid)

Answer 16

Use these tubes for
measuring biomarkers
in plasma (e.g., the
levels of inflammatory
cytokines, counting
cells SYSMEX)

Question 17

What is the significance of Heparin in Clinical testing

Answer 17

Use these tubes
assessing cell function
(i.e., can an immune cell
produce inflammatory
cytokines or kill virus
infected cells).

Question 18

Slides 9-12

Question 19

What is an example of immunity

Answer 19

Blood donation/transfusion

Question 20

What are 2 incompatibilities in blood donation/transfusion

Answer 20

he recipient’s anti-B antibodies cause the transfused cells to be attacked;

the anti-A antibodies in the transfused plasma cause the recipient’s cells to be attacked

Question 21

What is the most abundant class of plasma antibodies

Answer 21

IgG

Question 22

What do IgMs do

Answer 22

Class of antibodies that is produced first in all immune responses - providing bulk of specific humeral immunity against bacteria and viruses

Question 23

What are Igs and what are the 5 major classes

Answer 23

Immunoglobulin (Igs) are proteins that function as B-Cell receptors and antibodies

IgA, IgD, IgE, IgG, IgM

Question 24

What are Type 1 interferons

Answer 24

Group of cytokines that nonspecifically inhibit viral replication

Question 25

What are Type 2 interferons

Answer 25

(Interferon-gamma) stimulate the killing ability of NK cells and macrophages

Question 26

What does IL-1 do (interleukin 1)

Answer 26

Cytokine secreted by activated helper T cells that activates helper `T cells, exerts many inflammatory effects and mediates many of the systems acute phase responses, including fever

Question 27

What does IL-2 do

Answer 27

Cytokine secreted by activated T helper cells that causes helper T cells, cytotoxic T cells and NK cells to proliferate and causes activation of macrophages

Question 28

What does IL-6 do

Answer 28

Cytokine secreted by macrophages that exerts multiple effects on immune system cells, inflammation, fever, and acute phase response

Question 29

What do Kinins do

Answer 29

Peptides that split from kininogens in inflamed areas and facilitate the vascular changes associated with inflammation; they also activate neuronal pain receptors

Question 30

What is a MAC

Answer 30

Membrane Attack Complex - group of complement proteins that form channels in the surface of a microbe, making it leaky and killing it

Question 31

What are natural antibodies

Answer 31

Antibodies to the erythrocyte antigens (A or B type)

Question 32

What are opsonins

Answer 32

general name given to any chemical mediator that promotes phagocytosis

Question 33

What is Perforin

Answer 33

Protein secreted by cytotoxic T cells and NK cells that form channels in the plasma membrane of the target cell, making it leaky and killing it, (similar to a MAC)

Question 34

What is Tumor necrosis factor-alpha (TNF-alpha)

Answer 34

Cytokine secreted by macrophages that has the same actions as IL-1

Question 35

What are activated macrophages

Answer 35

Macrophages whose killing ability has been enhanced by cytokines, particularly IL-2 and interferon-gamma

Question 36

What is an APC

Answer 36

Cell that presents antigen, completed with MHC proteins on its surface to T cells

Question 37

What are B-cells

Answer 37

Lymphocytes that, upon activation, proliferate and differentiate into antibody-secreting plasma cells; provide major defence against bacteria, virus-infected cells and cancer cells; and bind antigen associated with class 1 MHC proteins

Question 38

What do cytotoxic T cells do

Answer 38

The class of T lymphocytes that, upon activation by specific antigen, directly attack the cells bearing that type of antigen; are major killer of virus-infected cells and cancer cells; and bind antigen associated with class 1 MHC proteins

Question 39

What are dendritic cells

Answer 39

Cells that carry out phagocytosis and serve as APC

Question 40

What is Eosinophils

Answer 40

Leukocytes involved in destruction of parasites and in immediate hypersensitivity

Question 41

What are Helper T cells

Answer 41

The class of T cells that, via secreted cytokines, play a stimulatory role in the activation of B cells and cytotoxic T cells; also can activate NK cells and macrophages, and bind antigen associated with class II MHC proteins

Question 42

What do lymphocytes do

Answer 42

The type of leukocyte responsible for adaptive immune response - B cells, cells NK cells

Question 43

What are macrophages

Answer 43

Cell type that 1- functions as a phagocyte 2- processes and presents antigen to helper T cells 3 - secretes cytokines involved in inflammation, activation of lymphocytes and the systemic acute phase response to infection or injury

Question 44

What are mast cells

Answer 44

Tissue cells that bind IgE and release inflammatory mediators in response to parasites and immediate hypersensitivity reactions

Question 45

What do memory cells do

Answer 45

B cells and cytotoxic T cells that differentiate during an initial immune response and respond rapidly during a subsequent exposure to the same antigen

Question 46

What are monocytes

Answer 46

A type of Leukocytes; leaves the bloodstream as a macrophage

Question 47

What do NK cells do

Answer 47

Class of lymphocytes that bind to cell smearing foreign antigens without specific recognition and kill them directly; major targets are virus-infected cells and cancer cells; participate in antibody-dependant cellular cytotoxicity (ADCC)

Question 48

What do neutrophils do

Answer 48

Leukocytes that function as phagocytes and also release chemicals involved in inflammation

Question 49

What do Plasma cells do

Answer 49

Cells that differentiate from activated B lymphocytes and secrete antibodies

Question 50

What are T cells

Answer 50

Lymphocytes derived from precursors that differentiated in the thymus