CHAPTER 17: Blood/Cardiovascular
I. Intro: Hematology = Study of blood
A. Flow thru blood vessels
Artery
Capillary
Oxygenated
Exchange (diffusion)
Vein
Deoxygenated
B. Blood Composition
a.
b.
Characteristics
a. alkaline pH = 7.4
b. 8% body weight
c. Bright Red vs Dark Red
Bright red
O2 rich
Dark red
O2 Poor
d. Male = 5 - 6 L (1.5 gallons)
Female = 4 - 5 L
c. Functions
a. Distribution:
- food
- Oxygen
- Wastes - CO2 (lungs), Nitrogenous wastes (KIdney)
- Hormones
b. Regulation:
- Body Temp
- pH homeostasis (Bicarbonate system)
- Fluid Volume - Salts and Proteins - Hold H2O
c. Protection:
- Antibodies, WBCs, Complement proteins
- clotting - prevent excess loss
d. Plasma:
- 90% H2O
- More than 100 dissolved solutes
e.g. calcium, wastes (urea) (bilirubin)
- Plasma Proteins = maintains osmotic balance (along with Na+)
a. Made by liver; not taken up by cells (e.g. Albumin)
II. Blood Cells = aka “Formed Elements”
- “different” cells
1. most amitotic (marrow made)
2. 2/3 Not true cells
3. Survive only a few days
A. Erythrocytes (red blood cells)
1. Most numerous blood cell
2. Anatomy
- Biconcave (held by spectrin protein [spectrin help RBC pliability])
- 7.5 micrometers in diameter
3. Hemoglobin - Carries oxygen = made of globin
2 alpha, 2 beta chains bound to ring-like heme group - each holds Fe
--> 1 billion O2 molecules
4. Functions:
- Hb caries O2 and CO2 (20%)
5. Production - (Hemopoiesis)
- made in red bone marrow (e.g. epiphysis of long bone)
- erythropoiesis - starts as pleuripotential stem cells
- blood needs balance: increase RBCs --> more viscous
decrease RBCs --> not enough oxygen
[hypoxia]
- Depends on Fe, B-vitamins, aminoacids, testosterone (more in
males) and EPO (erythropoietin)
- EPO is made in kidneys - depends on how much O2 getting to
kidney cells
6. Destruction
a. lifespan = 100-120 days
b. RBCs destroyed in spleen & liver (macrophages)
c. Hemoglobin
B. Leukocytes (white blood cells)
1. Intro: 4800-10800 WBCs/mm3
- Functions - Defense (viruses, bacteria, tumor cells)
- diapedesis = leave capillary bed
- granulocytes/agranulocytes
- 5 types
i. Neutrophils - never
Most
ii. Lymphocytes - let
I
iii. Monocytes - monkeys
I
iv.eosinophils - eat
V
v. basophils - bananas
Least
2. Granulocytes
a. Neutrophils (50 - 70% WBCs)
- granules take up basic & acidic dye
- bacteria slayers; first line of defense
- lysosome granules
- nuclei: 3-6 lobes (aka polymorpho nuclear leukocytes)
- mechanism: respiratory burst - neutrophils produce lots of H2O2
(peroxide) and bleach, defensins (spears), during phagocytosis
b. Eosinophils (2 - 4% WBCs)
- Nucleus: bilobed
- Granules: lysosomes break down parasites (not bacteria)
- Lessen allergies by digesting antibody-antigen complexes
c. Basophils (.5 - 1.0%)
- Largest granules (contain histamines)
a. vasodilate
b. attract WBCs
- Contain heparin
- Binds to IgE
3. Agranulocytes
a. Lymphocytes (20 - 25%)
- large nucleus; makes up most of cell volume
- most stored in lymphatic tissues e.g. spleen; lymph nodes
T-Cells
B-Cells
direct attack on enemy
plasma cells
e.g. cancer cells, viruses
antibodies
b. Monocyte (3 - 8%)
- Largest (18 Micrometers) diameter
- phago-cytic
- activates lymphocytes
- can become wandering
* production - red marrow = leukopoiesis
- hormonally stimulates by interleukins, CSFs (colony stimulating
factors)
I
I
V
make & made by T-lymphocytes
C. Leukemias
1. Renegade leukocyte from a single clone divides out of control
2. named according to abnormal cell type e.g. lymphocytic leukemia
Acute
Chronic
Quick Advancing
Slow Advancing
Children/Adolescents
Elderly (slowly weakening
immune system)
D. Infectious Mononucleosis
- contagious, viral (epstein-barr) links to leukemia
- “foamy” cytoplasm
- kissing
IV. Clotting
A. Platelets - cell fragments of megakaryocytes
- granules have clotting factors
- no nucleus or organelles
- Kept inactive by prostaglandins and NO2
B. Hemostasis: “halting of bleeding”
3 Phases:
a. Vascular Spasms:
- vasoconstriction - reduces blood loss
- due to chemicals releases by platelets + endothelial cells
b. Platelet Plug Formation
- platelets attach to collagen fibers of wounded vessel
- Positive feedback
- Thrombin (enzyme) activates platelets when attached:
- Platelet granules release:
a. seratonin enhances vascular spasms
b. adp attracts more platelets
- Fibrin threads reinforce
c. Coagulation (clotting) = blood made from liquid to gel
Intrinsic Pathway
Extrinsic Pathway
Vessel Endothelium
Rupture
Tissue Cell Trauma
Platelets stick to collagen
Tissue factor (TF) - made
by dying cells
PF3 (made by platelets)
Clotting Factors > 200
Prothrombiin activator
Prothrombin
Thrombin (measu
ured time to clot)
Fibrin
nogen
FIbrin (cross-linkages off fibrin polymer = CLOT)
C. Hemostatic Disorders
a. Thrombus = Clot in an unbroken blood vessel
b. Embolus = Floating thrombus
c. Embolism = Embolus that blocks (often lungs)
* Warfarin - interferes with Vit. K: liver production of procoagulants goes down
* Aspirin - 81 mg -----> 50% of decline in heart attacks
* Plasmin - natural clot buster
* Procoagulants - Vit. K helps liver make clotting factors
- broccoli
- cabbage
- cauliflower
* Anticoagulants - Vit E Quinone + O2
- e.g. Grapeseed
* TPA = clot busters used in stroke & Heart attack
D. Bleeding Disorders
a. Liver Malfunctions
- liver needed to absorb fat along with vitamin K
- Liver malfunction
a. more bleeding
b. less procoagulants made
c. less fat & Vit K absorption
b. Hemophilia = genetic
Hemophilia A (83%)
Factor VIII
Hemophilia B
Factor IX
Sex-linked (X chromosomes) (makes more)
Hemophilia C
Factor XI
Male and Female
Prolonged bleeding
genetically engineered Facto
or VIII
c. Abnormal Hemoglobin
a. Thalassemias =
- faulty/absent globin chain
- Hb fragile decrease RBCs [no problem]
- greek + Italian
b. Sickle Cell Anemia
- 1/287 of amino acids malformed in globin chain
- beta chains sticky w/ low O2
- RBC jams up in capillaries
- recessive
- malaria parasite
III. Blood Disorders
A. Anemia “lacking blood”
a. Blood has a low O2 carrying capacity
- insufficient RBC levels
Hemorrhagic Anemia
Cut wound blood loss
Hemolytic Anemia
Aplastic Anemia
RBC ruptures
red marrow inhibited
e.g.
- parsitic attacks
- mismatched blood types
e.g. Chemotherapy
radiation
b. Low Hemoglobin Count
- e.g. Iron deficiency anemia = RBC level normal but less hemoglobin in them
a. nutritional - not enough iron
- e.g. Pernicious Anemia = not enough Vitamin B-12
IV. ABO Blood Groups = Based on presence or absence of agglutinogens A or B
Blood:
A
B
AB
O
Agglutinogen
A
B
A&B
None
Antibodies
B
A
None
A&B
* Rh factor = Antigen (agg.) on RBC; 85% Rh+; 15% Rh-
2nd pregnancy, placenta ruptures + babys blood gets into mama---> Rh+ made
antibodies.
Treat: Rhogam
V. Diagnostic Blood Tests
a. Differential Cell Count
a. % WBCs [part of complete blood count]
b. Complete Blood count
- totals of formed elements
- Hematocrit
- Clotting factor tests
c. SMAC = Blood Chemistry Profile
e.g. Ca++ -------> Cancer
Bilirubin----> Liver
Urea -------> Kidney
d. Prothrombin Time = Rate of clotting