1. Chapter 19 The Cardiovascular System: Blood

2. Fluids of the Body Cells of the body are serviced by 2 fluids
Blood
composed of plasma and a variety of cells
transports nutrients and wastes
Interstitial fluid
bathes the cells of the body
Nutrients and oxygen diffuse from the blood into the interstitial fluid & then into the cells
Wastes move in the reverse direction
Hematology is the study of blood and blood disorders

3. Functions of Blood (Blood is a _____ Tissue)
Transportation
O2, CO2, metabolic wastes, nutrients, heat & hormones
Regulation
helps regulate pH through buffers
helps regulate body temperature
coolant properties of water
vasodilation of surface vessels dump heat
helps regulate blood pressure/water content of cells by interactions with dissolved ions and proteins
Protection (from disease & loss of blood)
Clotting
WBC’s

4. Physical Characteristics of Blood
Thicker (more viscous) than water and flows more slowly than water
Temperature of degrees F
pH range of
8% of total body weight
Blood volume
5 to 6 liters (1.5 gallons) in average male
4 to 5 liters (1.2 gallons) in average female
hormonal negative feedback systems maintain constant blood volume and osmotic pressure

5. Techniques of Blood Sampling
Venipuncture
sample taken from vein with hypodermic needle & syringe
median cubital vein (see pages 738 and 743)
why not stick an artery?
Veins are closer to the surface. Tourniquet and clenching fist make vein stand out
Finger or heel stick
common technique for diabetics to monitor daily blood sugar
method used for infants

6. Components of Blood Hematocrit 55% plasma 45% cells 99% RBCs
< 1% WBCs and platelets

8. Components of Blood – Blood Plasma
Straw colored
0ver 90% water
~7% plasma proteins
created in liver
confined to bloodstream
Albumins
Transport hormones and fatty acids
maintain blood osmotic pressure
globulins (immunoglobulins)
transport
antibodies bind to foreign substances called antigens
form antigen-antibody complexes
fibrinogen
for clotting
~2% other substances
electrolytes, nutrients, hormones, gases, waste products

9. Components of Blood – Formed Elements of Blood
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (special cell fragments)

10. Hematocrit Percentage of blood occupied by red blood cells Anemia
female normal range %
male normal range %
Higher due to higher levels of testosterone, which stimulates EPO production
Anemia
not enough RBCs or not enough hemoglobin
Polycythemia
too many RBCs (over 65%)
dehydration, tissue hypoxia, blood doping in athletes

11. Blood Doping Why? Increased oxygen delivery to cells Basic Methods
Injecting previously stored RBC’s (stored for about a month) before an athletic event
drugs available that mimic erythropoietin (EPO)
Dangerous
increases blood viscosity
may force heart to work harder
Banned by Olympic committee

12. Red Blood Cells (Erythrocytes)
Biconcave disk 8 microns in diameter (most capillaries are 8-10 microns in diameter)
Shape increases surface area/volume ratio
flexible for narrow passages
no nucleus or other organelles
no cell division or mitochondrial ATP formation
Normal RBC count
male 5.4 million per microliter
female 4.8 million per microliter

13. Red Blood Cells - Hemoglobin
Hemoglobin – found in the cytoplasm; oxygen-carrying protein that gives blood its red color
1/3 of cell’s weight is hemoglobin
Globin protein consisting of 4 polypeptide chains
One heme pigment attached to each polypeptide chain
each heme contains an iron ion (Fe2+) that can combine reversibly with one oxygen molecule

14. Red Blood Cells - Transport of O2 and CO2
Each RBC contains ~280 million hemoglobin molecules
Each hemoglobin molecule can carry 4 oxygen molecules from lungs to tissue cells
This oxygen binds to the Fe2+ in the heme
DO THE MATH – THAT IS SOME SERIOUS O2
Hemoglobin transports 13% of total CO2 waste from tissue cells to lungs for release
combines with amino acids in globin portion

15. Red Blood Cell - Life Cycle
RBCs live only 120 days
wear out from bending to fit through capillaries
no repair possible due to lack of organelles
new RBCs enter circulation at the same rate that old ones leave…2 million/second
Worn out cells removed by macrophages in spleen & liver
New RBCs are produced in the red bone marrow during erythropoiesis

16. Red Blood Cell Life Cycle

17. Negative Feedback Regulation of Erythropoiesis
Why might this occur? Low oxygen content (high altitude for example), anemia (can be due to lack of iron, lack of B12, etc), circulatory problems

18. White Blood Cells (Leukocytes)
Have a nucleus
Function: Combat pathogens and other foreign substances that enter the body
Granular or agranular classification based on presence of cytoplasmic granules made visible by staining
granulocytes are neutrophils, eosinophils and basophils
agranulocytes are monocytes and lymphocytes

19. WBC Physiology
Can live for months or years but most only live a few hours or days
Less numerous than RBCs and platelets
5,000 to 10,000 WBCs per microliter
1 WBC for every 700 RBC
Leukocytosis is a high white blood cell count
microbes, strenuous exercise, anesthesia or surgery
Leukopenia is low white blood cell count
radiation, shock or chemotherapy
Only 2% of total WBC population is in circulating blood at any given time
rest is in lymphatic fluid, skin, lungs, lymph nodes & spleen

20. Types of WBCs Granular Agranular
Neutrophils – phagocytic; respond quickly to bacteria
Eosinophils – combat inflammation in allergic reactions caused by basophils; phagocytize antigen-antibody complexes; destroy parasitic worms
Basophils – intensify inflammatory response of allergic reactions
Agranular
Monocytes (Macrophages) – phagocytic; take longer to respond but destroy large amounts of bacteria and clean up debris
Lymphocytes – major soldiers of the immune system
B cells – secrete antibodies; destroy bacteria
T cells – attack viruses, cancer cells and transplanted cells
Natural killer cells – attack infectious microbes and some tumor cells

21. Phagocytosis

22. Platelets (Thrombocytes)
Cell fragment with no nucleus
Normal platelet count is 150, ,000 per microliter
Comparision to other blood cell counts
5 million RBCs & 10,000 WBCs
Help stop blood loss by forming a platelet plug and releasing blood-clotting chemicals
Live 5-9 days and then removed by macrophages

23. Hemostasis
Stoppage of bleeding in a quick & localized fashion when blood vessels are damaged
Prevents hemorrhage - loss of a large amount of blood
Methods utilized
vascular spasm
platelet plug formation
blood clotting (coagulation = formation of fibrin threads)

24. Stop the Bleeding!!! - Vascular Spasm
Reflex contraction of smooth muscle of small blood vessels
Can reduce blood loss for several hours until other mechanisms can take over
Caused by damage to the muscle, substances released by platelets, and reflexes initiated by pain receptors

25. Stop the Bleeding!!! – Platelet Plug Formation
Step 1: Platelet Adhesion
Platelets stick to exposed collagen underlying damaged endothelial cells in vessel wall
Step 2: Platelet Release Action
Platelets activated by adhesion and release contents of vesicles
Vascular smooth muscle contracts and decreases blood flow through the injured vessel
Step 3: Platelet Aggregation
Activated platelets stick together and activate new platelets to form a mass called a platelet plug
Plug reinforced by fibrin threads formed during clotting process
Effective in small blood vessels and can stop blood loss completely if hole is not too large

26. Stop the Bleeding!!! – Blood Clotting

27. Intravascular Clotting
Thrombus
A stationary clot in an undamaged vessel
Thrombosis
clotting in an unbroken blood vessel
Can be due to the slow travel of blood
may dissolve spontaneously or dislodge & travel
Embolus
clot, air bubble, fat from broken bone, or debris traveling in the bloodstream

28. Anticoagulants and Thrombolytic Agents
Anticoagulants suppress or prevent blood clotting
Heparin
administered during hemodialysis and surgery
Warfarin (Coumadin)
antagonist to vitamin K that blocks synthesis of clotting factors
slower than heparin
Aspirin
Low doses can inhibit vasoconstriction and platelet aggregation

29. Blood Groups and Blood Types
RBC surfaces are marked by genetically determined glycoproteins & glycolipids
we call these antigens (agglutinogens/isoantigens)
distinguishes at least 24 different blood groups

30. ABO Blood Groups 2 antigens on RBCs: A and B
display only antigen A -- blood type A
display only antigen B -- blood type B
display both antigens A & B -- blood type AB
display neither antigen -- blood type O
Plasma contains antibodies (isoantibodies/agglutinins) to the A or B antigens not found in your blood
anti-A antibody reacts with antigen A
anti-B antibody reacts with antigen B

31. ABO Blood Groups Type O – universal donor (no antigens)
Type AB – universal recipient (no antibodies)

32. Rh blood groups Antigen was discovered in blood of Rhesus monkey
Rh+ = has the Rh antigen
Rh- = no antigens
Normal plasma contains no anti-Rh antibodies
Antibodies develop only in Rh- blood type & only with exposure to the antigen
transfusion of positive blood
during a pregnancy with a positive blood type fetus
Transfusion reaction upon 2nd exposure to the antigen results in hemolysis of the RBCs in the donated blood

33. Transfusion and Transfusion Reactions
Transfer of whole blood, cells or plasma into the bloodstream of recipient
used to treat anemia or severe blood loss
Incompatible blood transfusions
antigen-antibody complexes form between plasma antibodies & “foreign proteins” on donated RBC's (agglutination)
donated RBCs become leaky & burst
loose hemoglobin causes kidney damage

34. Blood Disorders Anemia Hemophilia
oxygen-carrying capacity of blood is reduced
fatigue, cold intolerance & paleness
lack of O2 for ATP & heat production
Hemophilia
Inherited deficiency of clotting factors
bleeding spontaneously or after minor trauma
subcutaneous & intramuscular hemorrhaging
nosebleeds, blood in urine, articular bleeding & pain
Treatment is transfusions of fresh plasma or concentrates of the missing clotting factor

35. Sickle-Cell Anemia Genetic defect in hemoglobin molecule (Hb-S)
Cells become sickle-shaped
sickle-shaped cells rupture easily = causing anemia & clots
Found among populations in malaria belt
Mediterranean Europe, sub-Saharan Africa & Asia
Person with only one sickle cell gene
increased resistance to malaria because RBC membranes leak K+ & lowered levels of K+ kill the parasite infecting the red blood cells

36. Leukemia Acute leukemia Chronic leukemia Signs and Symptoms
uncontrolled production of immature leukocytes
crowding out of normal red bone marrow cells by production of immature WBC
prevents production of RBC & platelets
Chronic leukemia
accumulation of mature WBC in bloodstream because they do not die
Signs and Symptoms
Clotting problems, suppressed immune response, anemia