Chapter 19 Notes Continued

Chapter 19 Notes Continued
including material from Chapter 22
The Cardiovascular System: The Blood

We must move to Chapter 22 to understand: Specific Immunity

7. Role of Lymphocytes in Immunity

antigen: a foreign substance that promotes the production of antibodies
antibody: a glycoprotein produced by the body that attaches to an antigen determinant site
antibody structure: "Y"
- heavy chain 2 long chains with 440 amino acids
- light chain on the arms of the Y, has 220 amino acids
- constant similar for each class of antibodies
- variable contains the antigen binding site
antibody online

classes of immunoglobulins (antibodies)

1. IgG - 80%
    - major immunoglobin produced by B cells
    - main protection against bacteria and viruses
    - also neutralizes toxins in tissues and triggers complement

2. IgA - 13%
    - main protection in mucous membranes and secretions
    - note presence in colostrum and milk

3. IgM - 5 -10%
- responsible for blood groups
- acts as receptors on B cell surfaces

4. IgD - ?? surface receptor on B cells

5. IgE: - bound to surfaces of mast cells and basophils
- when an antigen attaches to IgE molecules, histamine is released

antibodies attach to antigens and prepare them for phagocytosis or destruction by a group of proteins called complement
online antibody resource
NIAID site on immunity

8. T Lymphocytes

programmed in thymus gland
function in cell-mediated immunity
body defense against viruses, fungi, cancer and transplant cells
major histocompatibility complex: unique antigens on your cell membranes help T cells recognize foreign antigens
T cells recognize specific antigens and then require a costimulator for activation into four specific subpopulations

1. Helper T cells
- these are designated CD4 cells
- produce interleukin 2 which promotes killer T cell production
- when presented with an antigen by macrophages,
these induce antibody production by descendants of B cells

2. Cytotoxic T cells
- (Killer CD8 cells)
- destroy antigenic cells directly and mobilize neutrophils and macrophages

3. Memory T cells
- remain after immune response
- recognize original antigen in a second invasion

4. Suppressor T cells
- inhibit killer T cells and antibody formation

9. B Lymphocytes

source of processing unknown
function in antibody-mediated immunity
do their work in lymphatic tissue secrete into blood and lymph
combat bacterial and some viral infections
T cell interleukin 4 provides costimulation for B cells to divide and differentiate into

1. Plasma Cells
- produce large quantities of antibodies which combine with a specific antigen

2. Memory cells
- immunocompetent cells that react with an antigen upon another exposure

10. Monoclonal antibodies

method to produce a pure antibody in the lab
1. grow antigen in mouse
2. harvest B cells from mouse spleen
3. fuse B cells with tumor cells
4. cells are grown and a specific antibody can be isolated
5. clones produce unlimited amounts of pure antibody
uses for monoclonal antibodies
1. measures levels of drugs in blood
2. diagnose pregnancy, hepatitis, HIV
3. detect cancer
4. could be aimed directly at tumor cells
monoclonal antibodies discussion online

10. Anaphylaxis

violent reaction upon reexposure to an antigen
IgE antibodies on mast cells and basophils react with antigen
common with bee stings, seafood, and drugs
cells release histamine, prostaglandins, kinins
how IgE are manufactured online
results are life threatening
1. vasodilation and increased capillary permeability
2. smooth muscle contraction in airways
3. increased mucus secretions, runny nose

Blood Clotting

11. The platelet plug

a vascular spasm is the initial response to injury
then platelets form a mass
1. platelets stick to blood vessel
2. platelets release vasoconstrictors to narrow the blood vessel
3. other platelets are recruited and adhere to one another
4. the sticky platelet mass prevents blood loss
5. platelet aggregation and clotting online

12. Factors used in blood clotting

I - Fibrinogen
- forms fibrin threads which are the clot
II - Prothrombin
- blood protein formed in liver with help of Vitamin K
III - Tissue factor thromboplastin
- secreted by cells in damaged tissues
- initiates extrinsic pathway
IV - Calcium ions
- used in each stage of clotting
V - Labile factor, proaccelerin
- required at end of extrinsic and intrinsic pathway
VIII - Antihemolytic factor
- globulin synthesized in liver for intrinsic pathway
IX - Christmas factor
- synthesized in liver for intrinsic pathway
X - Stuart factor
- produced at end of extrinsic and intrinsic pathways
XIII - Fibrin stabilizing factor
- renders fibrin insoluble

clotting is a cascade of chemical interactions in three stages

Stage 1

extrinsic pathway	intrinsic pathway
tissue damage	endothelial damage
fast acting	slow acting
Tissue Factor III	Platelet Factor III
activates Factor VII	activates Factor XII
activates Factor X	activates Factor XI
	activates Factor IX
	activates Factor VIII
	activates Factor X

Factor X combines with Factor V in the presence of calcium to form Prothrombinase

	common pathway
	Stage 2
	Prothrombinase + Ca⁺⁺
Prothrombin	------------------------------>	Thrombin

	Stage 3
	Thrombin + Ca⁺⁺
Fibrinogen	------------------------------->	fibrin threads
	Stage 4
plasminogen	------------------------------->	clot dissolution

13. Anticoagulants

Heparin	Coumadin
administered by IV	oral
antagonist to thrombin	impairs livers use of Vitamin K
	blocks II, VII, IX, and X
fast acting, short lived	slow acting, long-lasting
monitored by APPT	monitored by ProT
tested by Activated Partial Thromboplastin Time	tested by Prothrombin Time
evaluates intrinsic pathway	evaluates extrinsic pathway

14. Thrombolytic agents

dissolve blood clots
TP-A and streptokinase

Blood Typing

15 . Blood Groups

on the surface of red blood cells are inherited glycoproteins
these act as antigens: A, B, and O (no)
- genotype IA IA or IA IO causes synthesis of antigen A
- genotype IB IB or IB IO causes the synthesis of antigen B
- genotype IA IB causes the synthesis of antigens A and B
- genotype IO IO lacks the information for synthesis of these proteins

natural antibodies are found in plasma
- type A blood has B antibodies
- type B blood has A antibodies
- type AB blood has no antibodies
- type O blood has A and B antibodies
- click here to see agglutination of antigens on red blood cells clumping with the antibody in
the plasma Always Check the Blood Type of donor and recipient!

incompatibility results when different blood types are mixed
antibodies in recipients plasma agglutinate donors red cells
five antigens involved in the Rh factor
- C, D, E, c, and e are red cell surface antigens
- presence of C, D, E may determine Rh+ blood
- antibodies against Rh antigens do not form naturally
- Rh- individuals sythesize the antibodies after exposure to Rh+ blood
Blood groups online
Blood typing game