Blood/Immunity Lab

BIOL 326L

Composition of Blood

• Total blood volume is ~ 5L

• Consists of formed elements (cells) suspended in plasma

• Plasma is liquid consisting of H20 & dissolved solutes– Includes

proteins/antibodies, ions, organic molecules, hormones

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Characteristics of Red Blood Cells

Red blood cells are:• Erythrocytes• Biconcave discs • One-third hemoglobin or:

• Oxyhemoglobin(+ oxygen)• Deoxyhemoglobin

• Able to readily squeeze through capillaries• Lack nuclei and mitochondria

.

Top view

2.0 micrometers

7.5 micrometers

Sectional view

(a)

(b)

b: © Bill Longcore/Photo Researchers, Inc.

Blood Type and Blood Typing using Antibody-Antigen

Immune Reaction

Antibodies/Antigens

Blood Typing & RBC Antigens • Antigens present on RBC surface specify blood type (A and B)• Major antigen group

– Type A blood has only A antigens– Type B has only B antigens– Type AB has both A & B antigens

• AB

– Type O has neither A or B antigens

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**many more antigens have been identified, and typing is going towards “gene chips”

Rh Factor

• Is another type of antigen found on RBCs

• Rh+ has Rho(D) antigens; Rh- does not

• RH+ most common

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Anitbodies• Type A blood = has

antibodies to Type B antigens• Type B blood = has

antibodies to Type A antigens• Type AB blood = doesn’t

have antibodies to either Type A or B antigen (“universal recipient”)

• Type O blood = has antibodies to both Type A & B antigens(“universal donor”)

• If different blood types are mixed, antibodies will cause mixture to agglutinate

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Agglutination• Type O- is “universal donor” because lacks

A & B antigens– Recipient’s antibodies won’t agglutinate donor’s

RBCs

• Type AB+ is “universal recipient” because doesn’t make anti-A or anti-B antibodies– Won’t agglutinate donor’s RBCs

• Can cause problems when Rh- mother has Rh+ babies– In Erythroblastosis fetalis, this happens & antibodies cross

placenta causing hemolysis of fetal RBCs

**remember, rxn. To donor antigens by

Recipient blood that causes problem, donor antibodies insignificant

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*

• Blood Typing– Anti-A=ab to A– Anti-B– Anti-Rho– Agglutination

= RBCs contain those antigens

RBC Count/ Hematocrit• Hematocrit = ratio of packed RBCs to blood

volume– Centrifuge blood sample in hematocrit tube – Normal

• Male = 47±7%• Female = 42±5%

Anemia can be due to loss of RBC’s, decreased production of RBC’s, or decreased hemoglobin synthesis (or destruction), resulting in inability to

Utilize oxygen properly

Anemia may result from destruction of RBC’s by oxidative damage or immune reaction against the RBC:

Heintz body anemia: oxidative damage to hemoglogin

Can be due to glucose-6-PO4 dehydrogenase deficiencyAnd subsequent sensitivity to quinine, other drugs

(onion toxicosis in dogs!)

Eccentrocytes: oxidative damage to RBC

IMHA and ITP: immune mediated Hemolytic anemia and idiopathic thrombocytopenia

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Neutrophils• Light purple granules in acid-base stain• Lobed nucleus when mature• Other names

• Segs• Polymorphonuclear leukocyte• Bands (young neutrophils)

• First to arrive at infections• Phagocytic• 54% - 62% of leukocytes• Elevated in bacterial infections

© Ed Reschke

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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Eosinophils• Deep red granules in cytoplasm• Bi-lobed nucleus• Moderate allergic reactions• Defend against parasitic worm infestations• 1% - 3% of leukocytes• Elevated in parasitic worm infestations and allergic reactions

© Ed Reschke

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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Basophils

• Deep blue granules in basic stain• Release histamine• Release heparin• Less than 1% of leukocytes• (least common)

© Ed Reschke

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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Monocytes• Largest of all blood cells kidney-shaped, oval or lobed nuclei• Leave bloodstream to become macrophages• 3% - 9% of leukocytes• Phagocytize bacteria, dead cells, and other debris

© R. Kessel/Visuals Unlimited

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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Lymphocytes• Slightly larger than RBC• Large spherical nucleus surrounded by thin rim of cytoplasm• T cells and B cells

• Both important in immunity• B cells produce antibodies• 25% - 33% of leukocytes

© Ed Reschke

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Platelets=thrombocytes

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CLOTTING DISORDERS:1. platelets =thrombocytopeniasdecreases ability to form primary

clot; leads to bleeding2. decreased clotting factor,

anywhere in clotting cascade=coagulopathy

clotting cascade leads to fibrin clot in healthy individual

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Blood Platelets

•Platelet adhesion can be decreased With drugs (aspirin/plavix) or some health problems*Platelet number can be decreased in disease states, causing bleeding*

Coagulopathies:

Decrease in any clotting factor can disrupt cascade, so fibrin prodn

prevented. Causes include: Von Willebrand’s, hemophilia, Vit.K

deficiency(used up in bleeding),almost any cancer, rodent poison

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Clotting tests:

1. PT=prothrombin timetests function of extrinsic and

common pathwayincreased time indicates problem

2. PTT=partial thrombin

tests intrinsic system so increased time indicates problem

Clotting tests:

aiha

Onion toxicosis