Blood

Biology 2122Chapter 17

Characteristics/Functions1. Connective Tissue (Formed Elements)

2. pH: 7.35-7.45

3. Males: 5-6 L; Females: 4-5 L

4. O2 and CO2 ; Hormone Transport

5. Regulatory (Body Temperature; pH; Fluids)

6. Protection: Antibodies-Immune System

Blood Composition 1. Plasma (55%)

– Dissolved solutes; Water

2. Formed Elements

– Erythrocytes; Leukocytes; Platelets

3. Buffy Coat

4. Proteins

– Albumin

Erythrocytes1. Function/Structure– Biconcave discs– No mitochondria – Functions

• Gas Transport; Hb and oxygen gas affinity

• Delivers oxygen gas to cells; carbon dioxide as waste

2. Concentration – Hematocrit – Females vs. Males

Production Hematopoiesis-Erythropoiesis

Life Span: 120 days

Stem Cell: Hemocytoblast

Regulation, Destruction and Disorders

Leukocyte Classification 1. Granulocytes – Neutrophils; Eosinophils;

Basophils– Larger; short-lived compared to

RBC

2. Agranulocytes – Lymphocytes; Monocytes– No cytoplasmic granules– Specific immune response

Characteristics of Granulocytes 1. Neutrophils – Polymorphonuclear

Leukocytes (PMNs)– Lilac stain

2. Eosinophils – Pink Granules (acid stain);

large– Parasitic Worms

3. Basophils– Lg. granules (blue-basic);

Histamine; U or S-shaped nuclei

Characteristics of Agranulocytes1. Lymphocytes– Dk. Purple Spherical

nuclei – T and B-Cells (Specific

Immunity)

2. Monocytes– U-Shaped nuclei– Macrophages

Leukocyte Production1. Leukopoiesis

2. Stem Cell

3. Stimulated by Chemical Messengers

– Glycoproteins (Interleukins and Colony-Stimulating Factors

4. Pathways

– Lymphoid vs. Myeloid Stem Cells

Blood Groups and Blood Types 1. ABO Groups – Based on presence or absence

of surface antigens (agglutinogens) – A or B

– Plasma: antibodies (agglutinins)

– Type O (universal donor); Type AB (universal receiver)

2. Rh antigens (Factors) – 85% are positive

3. Frequency– O>A>B>AB

Hemostasis – How Blood Vessels Repair Themselves

1. Blood vessels undergo damage – unseen

2. Hemostasis - response to this damage

3. “Plugging the Hole” – Clot Formation

4. Stages

– Vascular Spasm

– Platelet Plug

– Coagulation

Spasms and Plugs 1. Vascular Spasm– Damaged blood vessels (vascular smooth muscle) --------

Chemicals ------------ constriction (spasm)– “Vasoconstriction” – Most Effective – small blood vessels

2. Platelet Plug Formation– Platelets “aggregate” ------ Plug (temporary)– Adhere to exposed collagen fibers – Von Willebrand factor; ADP; Serotonin; Thromboxane

Coagulation – ‘blood clotting’1. Multi-step pathway

(mediated by clotting proteins)

2. Platelets – reinforced by fibrin (fibrin mesh)

3. Clotting Factors (plasma proteins) – Factors activated (enzyme)

– Cause a ‘cascade effect’

– I – XIII

Pathways

Pathways - Prothrombin Activator1. Both factors cascade – common factor X

– Prothrombin activator

2. Prothrombin activator catalyzes transformation of prothrombin to thrombin.

3. Thrombin

– Fibrinogen ---------- Fibrin

– Insoluble strands glue platelets – clot

– Factor XIII activated (binds fibrin strands)

Hemostasis 4. Clot Retraction – stabilizes the clot

5. PDGF – promotes smooth muscle cells and fibroblast to repair wall.

6. Fibrinolysis – removes unnecessary clots

– Plasmin (clot buster)

– Heparin; Antithrombin III (anticoagulants)

– Hemostasis Animation

Disorders

1. Thromboembolic Disorders – Thrombus– Embolus – Embolism – DVT Animation

2. Bleeding Disorders – Hemophilia