Chapter 19
Cardiovascular System
Blood…
Cardiovascular System Components
Heart
Arteries
Arterioles
Capillaries
Venules
Veins
Substances transported in blood
Hormones – endocrine to target organs
Nutrients – digestive to metabolism, digestive to site of
storage and site of storage to metabolism
O2 – lungs to tissue and tissue to lungs
CO2 – tissue to lungs
Antibodies
Water – digestive to tissues, tissues to kidneys, excretion
Nitrogenous wastes – metabolized protein to kidneys-excretion
Electrolytes – absorbed as needed
Blood consists of two fractions…
Plasma – liquid portion = 55% total volume
Formed elements – cellular = 45% total volume
Hematocrit
Main component of plasma
Water = 91%
Solutes found in plasma
Proteins:
Albumins – acid/base balance, osmolarity
Globulins – antibody fraction
Fibrinogen – a clotting element
Prothrombin – a clotting element
Other solutes in plasma
Ions: Na+, K+, Ca++, Phosphate
Nutrients – carbohydrates, lipids, proteins, nucleic acids
Waste products – e.g. urea
Gases – e.g. O2 & CO2
Regulatory Substances – hormones & enzymes
Formed Elements
Erythrocytes = Red Blood Cells (RBCs)
Leukocytes – White Blood Cells
(several types, to be described shortly)
Platelets – cell fragments used in forming plugs,
Release chemicals necessary for clotting
Composition of blood fig
Erythrocytes
Cell shape is round & biconcave
Non-Nucleated – lack nucleus and many other organelles
Contain hemoglobin – primary function is to transport O2
and remove CO2
Hemoglobin has quaternary level of protein organization
Quaternary organization – globular protein composed of
Two or more proteins bonded together (Hb has four proteins
Two  (alpha) proteins and two  (beta) proteins
Hemoglobin
Hematopoesis – RBC production
Produced in the red bone marrow
Production regulated by O2 levels in blood
When O2 levels drop below a point, kidneys release
renal erythropoetic factor
REF converts inactive erythropoetin into its active form
When activated, erythropoetin causes red bone marrow
To initiate erythropoesis – formation of RBCs
Erythrocyte production
Hematopoesis figure
End fate of RBC
Lifespan = 80 – 120 days
Macrophages engulf RBC
Heme is transferred into an iron & biliverdin
Biliverdin converted to bilirubin
Iron transported to spleen, liver & bone marrow – eventually
recycled into new RBCs
Bilirubin taken to liver & excreted with bile into intestine
where it passes in feces or is excreted by kidneys
Globin (protein portion) broken down into amino acids
and recycled
White Blood Cells - Leukocytes
GRANULOCYTES
1. Neutrophils
2. Eosinophils
3. Basophils
AGRANULOCYTES
1. Lymphocytes
2. Monocytes
PLATELETS (thrombocytes)
Function & recognition of Granulocytes
Neutrophils – phagocytic, attack bacteria & viruses
Recognize by multi-lobed nucleus (3+ lobes)
Eosinophils – granules contain lysosomes and secretory vessicles, attack
parasitic invasions, secrete substances to counteract alergic responses such
as antihistamines
Recognize – dumbbell shaped (bilobed) nucleus. Granules stain
Red with eosin
Basophils – granules are secretory vessicles active during allergic &
inflamatory responses During these responses they may become activated
into a MAST CELL which can then release histamine and heparin.
Histamine – vasodilator & increases permeability of capillaries
Heparin – anticoagulant
Recognize –dumbbell shaped nucleus. Granules stain purple/black
Function & recognition of Agranulocytes
Lymphocytes – named for the type of cellular receptors they
have.
1. B-Cells – when activated produce antibodies
2. T-Cells – protect against viruses by attacking and destroying
cells in which viruses are reproducing.
Involved in destruction of tumor cells.
Involved in tissue graft rejections (recognition of self/non self)
Function & recognition of Agranulocytes
Monocytes – Very large white blood cells – bean shaped
nucleus. Phagocytic – engulf foreign pathogens such as
bacteria. They then take cellular markers from these foreign
cells and attach them to their cell membranes. As such they
become an ‘antigen-presenting macrophage’ and can serve as
activators for the immune response. They can then go find
lymphocytes and activate them to recognize the invading
pathogenic organisms
Platelets – fragments of megakaryocytes. Serve as a physical
plug in clot formation. Produce thromboplastin (a clotting element).
Blood Typing
Antigen – Markers (often associated with cell surface) that are
recognized as self or non-self. (A, B and Rh are antigens on the
surface of red blood cells
Antibodies – blood proteins that recognize non-self antigens
ABO Blood Group
1. A-Proteins
2. B-Proteins
3. There is NO ‘O’ protein,
O shows the LACK of A or B
Rh Factor – another protein that may/not be present
Rh+ has protein
Rh- lacks protein
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Genetics of Blood Type
Type A may have genotype AA or AO
Type B may have genotype BB or BO
Type AB must be AB
Type O must be OO
A parent may pass on either of the genes they carry
Blood Donor/Recipient Rules
Simply stated – you can never give someone a blood antigen
they don’t normally make themselves
Individuals have antibodies that will attack any blood antigen
they don’t make themselves
Blood type B has Anti-A antibodies
Blood type A has Anti-B antibodies
Blood type AB has neither because it makes both A & B proteins
(why attack yourself?)
Blood type O has both Anti-A & Anti-B antibodies
The End.