Anatomy and Physiology

Biology 2122KFloyd College

CARDIOVASCULAR SYSTEM

BLOODHEART

BLOOD VESSELS

Course Syllabus

http://www.floyd.edu/academics/divisions/smpe/biology/jhargettOr go to:www.floyd.edu and follow links to

academics, science & math, biology, adjuncts, Hargett

Hematology - study of blood

BLOOD Liquid connective tissue

comprising 8% of body weight 4-5 times more viscous than water,

salty Volume - 4-6 liters

8-12 pints

FUNCTIONS Transportation - oxygen, CO2, nutrients,

hormones and wastes

Protection - have cells that phagocytize bacteria and produce antibodies; clotting mechanisms that prevent blood loss

Regulation - pH, body temperature,water content

Components of Blood PLASMA - is the liquid portion of the blood and

consists primarily of water (92%) and plasma proteins (7%)

Proteins - albumin, globulins, and fibrinogen FORMED ELEMENTS - solid component of the

blood consisting of erythrocytes, leukocytes, and platelets

BLOOD = 55% plasma + 45% formed elements

Types of Cells Erythrocytes - Red Blood Cells

Carry oxygen Leukocytes - White Blood Cells

Immunity Thrombocytes – Platelets

Blood Clotting

Erythrocytes Very flexible, biconcave disk lacking a

nucleus Most numerous of cells; 5million/mm3

Transport respiratory gases such as oxygen and carbon dioxide

Approximately 120 day life span Hemoglobin - Consists of 4 polypeptide

globin chains with a heme molecule in each one Each hemoglobin molecule can carry four

oxygen molecules

Each RBC can contain up to 250 million hemoglobin molecules!

Types of Tests Red blood cell count –

4.3 – 5.8 million/mm3

Hemoglobin – 11.8 – 15.9 g/dl - Females 13.8 – 18.4 g/dl - Males

Hematocrit - 35-47% in Females 41-54% in Males

Reticulocyte – measures rate of RBC production

Hematopoiesis Occurs in red marrow Produces 1 oz. (100 billion cells) /day Stem cells called hemocytoblasts produce all

types of blood cells. Erythropoiesis:

Hemocytoblast (stem cell) Proerythroblast Erythroblast (large numbers of ribosomes

produce hemoglobin and store iron) Normoblast - loses nucleus and organelles Reticulocyte - immature (still contain E.R.) Erythrocyte - full process = 5-7 days

Hormonal control of blood production Erythropoietin

Produced by kidneys & liver Production due to:

Reduced RBC count Reduced oxygen availability Increased tissue demands

Leukocyte - WBC Granulocytes -

Neutrophils - phagocytize bacteria (60-70%);

Eosinophils - associated with allergic reactions and parasitic infections (2-4%)

Basophils - involved in the inflammatory response as well as allergic reactions; granules contain heparin and histamine (0.5-1%)

Agranulocytes - play a crucial role in immunity Monocytes - phagocytic macrophages

(3-8%) Lymphocytes - involved in immunity;

B cells and T cells (20-25%)

Thrombocyte - Platelet

Cytoplasmic fragments that are essential in blood clotting; help form a platelet plug

Platelets have a life span of only 5-9 days

Normal platelet count :250,000-400,00/mm3

HEMOSTASIS

Blood clotting

Stages of blood clotting

Vascular spasms - blood vessel constriction

Formation of a platelet plug - platelets stick to each other and the collagen exposed in the damaged tissue to form a plug

Coagulation - formation of a clot

Coagulation

Involves two chemical, enzymatic pathways resulting in the conversion of soluble fibrinogen into insoluble fibrin

Extrinsic pathway - cell trauma releases TF Intrinsic pathway - all components in blood Thirteen clotting factors involved; most are

produced in the liver Vitamin K dependent - II, VII, IX, X

Stages of blood clotting

Formation of prothrombinase (prothrombin activator)

Conversion of prothrombin to thrombin

Conversion of soluble fibrinogen into insoluble fibrin

Factor (procoagulants) sequence

12 - Hageman (glass) Factor 11 - Plasma thromboplastin antecedent 7 - Serum prothrombin conversion

accelerator 4 - Calcium ions 9 - Plasma thromboplastin component 8 - Antihemophilic factor 10 - Stuart Factor (thromboplastin)

Coagulant Factor Sequence (con’t)

10 - Stuart Factor 4 - Calcium Ions 3 - Tissue Factor 5 - Proaccelerin 2 - Prothrombin Thrombin

1 - Fibrinogen Fibrin 13 - Fibrin stabilizing factor

Forms

prothrombin

activator

Coagulation

Normal coagulation involves: normal platelets clotting factors vitamin K calcium

Clot Retraction - contractile proteins tighten clot

Fibrinolysis - clot dissolves

Clotting Disorders Thrombus - stationary clot

Embolus - circulating clot

Thrombocytopenia - deficient number of platelets

Hemophilia - genetic bleeding disorder

Hemophilia 3 types Hemophilia A (classical) - lack of factor VIII. Hemophilia B - lack of factor IX Hemophilia C - lack of factor XI Types A & B are sex-linked recessive.. Appeared in the royal families of Europe,

beginning with the children of Queen Victoria

Blood Groups - Typing

Blood is typed into groups depending upon the type of agglutinogens (antigens) present on the red blood cell surface

The plasma may contain genetically determined agglutinins or antibodies against the blood group antigens that they DO NOT have

The ABO and Rh system are based upon antigen-antibody type responses

Blood Typing ABO system - people who posses the A

antigen on the RBC surface are type A; if you posses the B antigen you are blood type B; if both A and B are present you are type AB; if neither A or B antigens are present, your blood type is O

Type O - universal donor, can give blood to anyone

Type AB - universal recipient, can receive blood from any blood type

Rh system - individuals whose red blood cells possess the Rh antigen are Rh+ (Approx 85%) Antibodies against Rh antigens are not

present at birth but are stimulated by exposure

Hemolytic Disease of the Newborn Only in Rh- mothers and an Rh+ child,

after exposure. RhoGam - medication given to

prevent sensitization of Rh- mother

Blood Disorders - Erythrocytes

Anemia – due to decreased number of red blood cells or a deficiency of hemoglobin

RBC deficiency aplastic anemia - destruction of bone marrow

hemorrhagic anemia - blood loss hemolytic anemia - rupture of RBC’s

Hemoglobin deficiency pernicious anemia - vitamin B12 deficiency

iron deficiency

Blood Disorders - Erythrocytes

Thalassemia - faulty hemoglobinFound in people of Mediterranean descent

Sickle-cell - faulty hemoglobinFound primarily in Africa and people of African descent.Provides resistance against Malaria

Polycythemia - excess RBC’s.

Sickle Cell Anemia

White blood cell disorders Leukopenia / leukocytosis Infectious mononucleosis

excess numbers of agranulocytes caused by Epstein-Barr virus

Leukemia predominate cell type acute (quick advancing chronic (slow advancing)