Chapter 19: The Cardiovascular System: The Blood Flashcards
Cardiovascular System
Consists of 3 interrelated components
1. Blood
2. Heart
3. Blood vessels
Hematology
Branch of science concerned with the study of blood, blood forming tissue and disorders associated with them.
Blood
Liquid connective tissue that consists of cells surrounded by a liquid extracellular matrix.
Functions of Blood
- Transportation: blood transport O2 from lungs to cells and CO2 from the cells to the lungs for exhalation.
- Regulation: helps maintain homeostasis of all body fluids. Helps regulate pH through the use of buffers.
Helps regulate body temp through heat absorption and coolant properties of water. - Protection: blood clots which protects against excessive loss from CVS after injury.
Physical Characteristics of Blood
Denser and more viscous than water
Feels sticky.
Temp is 38.
Slightly alkaline pH from 7.35-7.45.
Color varies with O2 content: when saturated bright red, when unsaturated dark red.
Consists of : 20 % Extracellular fluid
Components of Blood
Whole blood has 2 components
1. Blood plasma: watery liquid extracellular matrix that contains dissolved substances. Straw colored.
2. Formed elements; cells and cell fragments.
Blood Plasma Contents
- Plasma Proteins 7%: albumin, globulins, fibrogen
- Water 91.5 %
- Other solutes 1.5%: lates, nutrients, gases, reg substances, waste products.
Formed Elements Content
1: Platelets
2: White Blood Cells: neutrophils, lymphocytes, monocytes, eosinophils, basophils
3. Red blood cells
Plasma Proteins
7%
Proteins confined to blood. Hepatocytes (liver cells) synthesize most plasma proteins.
Responsible for colloid osmotic pressure.
Major contributors to blood viscosity.
Antibodies
Blood cells that developed into cells that produce gamma globulins, a type of plasma proteins.
Produced during certain immune responses.
Water in Blood
91.5 % Liquid portion.
Solvents and suspending medium. Absorbs, transport and releases heat.
Buffy Coat
Thin layer between the packed RBC and plasma in centrifuged blood.
Consists of 1% formed elements: WBC and platelets.
Due to the less dense than RBC and more dense than blood plasma.
Blood Plasma
Straw colored liquid when formed elements are removed from blood.
91.5 % water and 8.5 % solutes most of which are proteins.
Albumins in Blood Plasma
Smallest and most numerous plasma proteins.
Help maintain osmotic pressure.
Globulins in Blood Plasma
Large proteins, plasma cells produce immunoglobulin or antibodies.
Help attach virus and bacteria.
Alpha and beta globulins transport iron, lipids and fat soluble vitamins.
Fibrinogen ion Blood Plasma
Large protein.
Plays essential role in blood clotting.
Electrolytes in Blood Plasma
Inorganic salts, Pos cations: NA, K, Ca, Mg. Neg anions: Cl, HPO4, So4, HCO
Help maintain osmotic pressure and play essential roles in cell functions.
Nutrients in Blood Plasma
Products of digestion: amino acids, glucose, fatty acids, glycerol, vitamins and minerals.
Essential roles in cell function, growth and development.
Gases in Blood Plasma
O2: cellular functions
CO2: involved in the regulation of blood Ph.
N2: no known function
Regulatory Substances in Blood Plasma
Enzymes: catalyzes chemical reactions
Hormones: regulate metabolism, growth and development
Vitamins: cofactors for enzymes, reactions.
Waste Products in Blood Plamsa
Ureas, uric acid, creatine, creatinine, villi, ammonia
Most are breakdown products of protein metabolism that are carried by the blood to organs of excretion.
Red Blood Cells
Or erythrocytes
Transport O2 from the lungs to body cells and deliver CO2 from body cells to the lungs.
White Blood Cells
Or leukocytes.
Protect the body from invading pathogens and other foreign substances.
Contains: nuclei and other organelles.
Do not contain hemoglobin.
Either: granular or argranular leukocytes
Types of White Blood Cells
- Neutrophils
- Basophils
- Eosinophils
- Monocytes
- Lymphocytes: B cells, T cells,natural killer cells (NK).
Platelets
Fragments of cells that do not have a nucleus.
Release chemicals that promote blood clotting when blood vessels are damaged.
Functional equivalent: thrombocytes.
A high platelet count would mean failure of the spleen to destroy aged platelets.
Precursor cell: megakaroblast transforms into megakarocytes
Hematocrit
Percentage of total blood volume occupied by RBCs.
Normal range is 38-48% for adult.
Hemopoiesis
The process by which the formed elements of blood developed .
Before birth developed in the yolk sac of an embryo.
Primary site: red bone marrow last 3 months before birth.
Red Bone Marrow
Highly vascularized connective tissue located in the microscopic spaces between trabecular of spongy bone tissue.
Present chiefly in: bones of axial skeleton, pectoral and pelvic girdle, proximal epiphyses of humerus and femur.
Pluripotent Stem Cells
About 0.05-0.1% of red bone marrow cells.
Derived from mesenchyme. Have the capacity to develop into many different types of cells.
Produce: myeloid and lymphoid stem cells
Myeloid Stem Cells and Lymphoid Stem Cells
Produced by pluripotent stem cells in red bone marrow.
These cells have the capacity to develop into several types of cells.
Myeloid Stem Cells
Begin in red bone marrow.
Give rise to red blood cells, platelets, monocytes, neutrophils, eosinophils, basophils and mast cells.
Lymphoid Stem Cells
Give rise to lymphocytes and natural killer (NK).
Begin their development in red bone marrow but complete it in the lymphatic tissue.
Progenitor Cells
When myeloid stem cells differentiate during hemopoiesis.
No longer capable of reproducing themselves.
Committed to giving rise to more superficial elects of blood.
Precursor Cells
“Next generation cells” also known as blasts.
Over cell division, develop into the actual formed elements of blood.
Hemopoietic Growth Factors
Hormones that regulate the differentiation and proliferation of particular progenitor.
Erythropoietin (EPO)
Increases the number of red blood cells precursors.
Produced by Kidney cells.
Thrombopoietin (TPO)
A hormone produced by the liver that stimulates the formation of platelets from megakaryocytes.
When deficient with this hormone the person is likely to suffer from a blood clotting disorder.
Cytokines
Small glycoproteins that are typically produced by cells such as red bone marrow cells, leukocytes, macrophages, fibroblasts, and endothelial cells.
Colony-Stimulating Factors (CSFs) and Interluekins
Two important families of cytokines. Stimulate white blood cell formation.
Hemoglobins
Protein in RBC.
Pigment that gives whole blood its red color.
Contains iron ion that combines to 1 O2 molecule.
Normal male level: 13.5-18g/100ml
Normal female level: 12-16g/100ml
RBC Anatomy
Biconcave discs, diameter 7-8 um.
Simple structure, PM strong and flexible, allows them to deform without rupturing as they squeeze through narrow blood capillaries.
Lack nucleus, and other organelles.
RBC Physiology
Highly specialized for o2 transport.
Lack nucleus and mitochondria.
Generate ATP anaerobically. Do not use any O2 that they transport.
Globin
Protein of hemoglobin molecule. Composed of 4 polypeptide chains.
Ring like non protein pigment called: heme
Heme
Ring like no protein pigment in globin.
Bound to each of the four chains.
Nitric Oxide (NO)
Gaseous hormone.
Produced by endothelial cells that line blood vessels and bind to hemoglobin.
RBC Life Cycle
RBC live 120 days due to wear and tear on the PM as they squeeze through blood capillaries.
Transferrin
Transporter for Fe3+ in the bloodstream.
Ferritin
Iron storage protein
Biliverdin
A green pigment formed with iron is formed from heme.
Bilirubin
Yellow-orange pigment that is converted from Biliverdin (green pigment)
Urobilinogen
Bilirubin that is converted by the bacteria in the large intestine.
Uroblilin
Yellow pigment
Occurs when urobilinogen is absorbed back into the blood. Excreted in urine.
Stercobilin
Brown pigment, urobilinogen that is elimate in feces.
Gives feces its color.
Proerythroblast
Precursor cell. Starts erythropoiesis in red bone marrow.
Divides several times, producing cells that begin to synthesize hemoglobin.
Reticulocyte
A cell near the end of the development sequence that ejects its nucleus.
Hypoxia
O2 deficiency at the tissue level.
Neutrophils
Elevated amount in blood: bacterial infection, inflammation, burns, stress
Reduced amount in blood: radiation exposure, drug toxicity, vit B deficiency.
Smallest, evenly distributed, pale lilac.
Polymorphonuclear Leukocytes (PMNs)
Older neutrophils that have several differently shaped nuclear lobes.
Eosinophils
Elevated amount in blood: parasitic infection
Reduced amount in blood: drug toxicity, stress
Large, uniform sized granules.
Stain red orange with acidic dyes.
Do not cover or obscure the nucleus
Basophils
Round, variable sized. Are basic loving.
Elevated amount in blood: allergic reaction reduced amount in blood: pregnancy, ovulation, stress, hypothyroidism
Stain blue purple with basic dyes.
Commonly obscure the nucleus, 2 lobes.
At site of inflammation they leave capillaries, enter tissues and release granules that contain heparin, histamine, and serotonin.
Lymphocytes
Stains dark and is round/slightly indented.
Elevated amount in blood: viral infection
Reduced amount in blood: prolonged illness, HIV
Cytoplasm stains sky blue and forms a rim around the nucleus.
Considered major soldiers in lymphatic system battles.
T cells are subset of this type of WBC, attack infected body cells, tumors.
Responsible for transfusion reactions and rejection of transplanted organs.
Monocytes
Elevated amount in blood: viral or fungal infection, TB, leukemia
Reduced amount in blood:L bone marrow suppression
Cytoplasm is blue-gray, has foamy appearance.
Differentiate into macrophages.
Macrophages
Monocytes differentiate into macrophages.
Phagocytes cells that inject and destroy microbes, cell debris or other foreign matter.
Fixed Macrophages
Reside in a particular tissue.
Wandering Macrophages
Roam the tissues and gather at sites of infection or inflammation.
Major Histocompatibility (MHC) Antigens
Proteins in WBC and other nucleated cells in the body. Protrudes from their plasma membrane into extracellular fluids.
Leukocytosis
Increase in the number of WBC above 10,000 ul. A normal, protective response to stresses.
Leukopenia
Abnormally low level of WBC. Below 5000ul.
Emigration
Process where WBC leave the bloodstream.
WBC roll along the endothelium, stick to it and squeeze between endothelial cells.
Adhesion Molecules
Molecules that help WBC stick to endothelium.
Adhesion molecule: selectins in response to nearby injury and inflammation.
Integrins
Tether neutrophils to the endothelium and assist their movement through the blood vessel wall and into the interstitial fluid of the injured tissue.
Phagocytes
Ingest bacteria and dispose of dead matter.
Neutrophils and macrophages are active in phagocytes.
Chemotaxis
Phenomena were several different chemicals released by microbes and inflamed tissues that attach phagocytes.
Lysozyme
Enzyme chemical that destroys pathogens, certain bacteria, and strong oxidants.
Defensins
Contained in neutrophils. Proteins that exhibit a broad range of antibiotic activity against bacteria and fungi.
Differential WBC
Or diff
A blood test that counts each of 5 types of white blood cells.
Detect infection or inflammation. Determine the effects of possible poisoning by chemical or drugs.
Platelet
Fragment that break off from the megakaryocytes in red bone marrow and then enter the blood circulation.
Hemostasis
Sequence of responses that stops bleeding.
3 mechanisms that reduce blood loss
1. Vascular spasm
2. Platelets plus formation
3. Blood clotting (coagulation)
When successful, prevents hemorrhage.
Vascular Spasm
Reaction where arteries or arterioles that are damaged, the smooth muscle in the walls contracts immediately.
Fibrin-Stabilizing Factor
Helps strengthen a blood clot in platelets.
Platelet-Derived Growth Factor (PDGF)
A hormone that can cause proliferation of vascular endothelial cells, vascular smooth muscle fibers, and fibroblasts to help repair damaged blood vessels walls.
Serum
Straw colored liquid.
Blood plasma minus the clotting proteins.
Blood Clot
The gel.
When blood is drawn from the body it thickens and forms a gel.
Consists of a network of insoluble protein fibers called fibrins.
Clotting
The process of gel formation.
A series of chemical reactions that culminates in formation of fibrin threads.
Thrombosis
If blood clots too easily.
Clotting in an unmanaged blood vessel.
If blood takes too long to clot, hemorrhage can occur.
Clotting Factors
Several factors are needed for clotting to occur.
Calcium ions, several inactive enzymes that are synthesized by hepatocytes, and various molecules associated with platelets.
Clotting factors: ADP, ATP, Ca2+, Serotonin
Fibrinogen is transformed into fibrin which forms threads of a clot.
3 Stages of Clotting
- Two pathways: extrinsic and intrinsic pathway. Leads to the formation of prothrombinase. Once this starts leads to the 2 stages that are referred to Sam’s common pathway.
- Prothrombinase converts prothrombin into the enzymes thrombin.
- Thrombin converts soluble fibrinogen into insoluble fibrin. Fibrin forms the threads of the clot.
Extrinsic Pathway
Blood clotting in this pathway has fewer steps than the intrinsic pathway and occurs rapidly.
Tissue protein called tissue factor leaks into the blood from cells outside blood vessels and initiates the formation of prothrombinase.
Tissue Factor (TF)
Or thromboplastin
Tissue protein.
Complex mixture of lipoproteins and phospholipids released from the surface of damaged cells.
In the presence of Ca2+, TF behind the sequence of reaction that activates clotting.
Intrinsic Pathway
More complex, occurs slowly, requiring several minutes.
Activators are either in direct contact with blood or contained within the blood. Outside tissue damage is not needed.
Common Pathway
1st stage: Begins with the formation of prothrombinase.
2nd stage: Prothrombinase and Ca2+ catalyzes the conversion of prothrombin to thrombin.
3rd stage: thrombin in the presence of Ca2+ converts fibrinogen to loose fibrin threads.
Clot Retraction
The consolidation or tightening of the fibrin clot.
As the clot retracts, it pulls the edges of the damaged vessels closer together, decreasing the risk of further damage.
Role of Vitamin K in Clotting
Normal clotting needs adequate level of K in the body.
Is required for the synthesis of 4 clotting factors.
Fibrinolytic System
Homeostasis control of clots
Dissolves small, inappropriate clots.
Also dissolved clots at the site of damage once the damage is repaired.
Fibrinolysis
Dissolution of a clot.
Plasminogen
Inactive enzyme that is incorporated into the clot when a clot is formed.
Plasmin
Or fibrinolysin
Active plasma enzyme.
Substance that can activate plasminogen. Found in both body tissue and blood.
Prostacyclin
Produced by endothelial cells and WBC.
Opposes the actions of thromboxane A2.
Powerful inhibitor of platelet adhesion and release.
Anticoagulants
Substance that delay, suppress, or prevent blood clotting that are present in blood.
Heparin
Anticoagulant.
Produced by mast cells and basophils. Combines with antithrombin and increases its effectiveness in blocking thrombin.
Activated Protein C (APC)
Anticoagulant
Inactivates the 2 major clotting factors not blocked by antitrombin and enhances activity of plasminogen activators.
Intravascular Clotting
Clots that are initiated by roughened endothelial surfaces of a blood vessel resulting from atherosclerosis, trauma or infection.
May also form when blood flows too slowly, allowing clotting factors to accumulate locally.
Thrombosis
Clotting that forms in an unbroken blood vessel usually a vein.
Thrombus
Clot formed in thrombosis.
May dissolve spontaneously.
Embolus
A blood clot, bubble of air, fat from broken bones or apices of debris transported by the blood stream.
Pulmonary Embolism
When an embolus lodges in the lungs.
Antigens
Or agglutinogens, occur in characteristic combination.
Genetically determined assortment contained on the surface of erythrocytes.
Composed of glycoproteins and glycolipids.
Blood Groups
Is based on the presence or absence of various antigens.
Blood Types
May be 2 or more different types within a given blood group.
ABO Blood Group
Based on 2 glycolipids antigens called A and B.
Type A
RBC display only antigens A.
Type B
RBC that only have antigens B.
Type AB
RBC that have both A and B antigens.
Consider the universal recipient as they can have blood from A, B, AB, O
Type O
Neither antigens A nor B in RBCs.
Antibodies
Contained in blood plasma that react with the A or B antigens if the 2 are mixed.
Anti-A Antibody
Antibodies that react with antigen A.
Anti-B Antibody
Antibodies that reacts with antigen B.
Transfusion
The transfer of whole blood or blood components into the blood stream or directly into the red bone marrow.
Agglutination
Happens during an incompatible blood transfusion. Antibodies in the recipients plasma blind to antigens on the donated RBCs.
An antigen-antibody response in which RBCs become cross linked to one another.
Hemolysis
Rapture of the RBCs and the releases of hemoglobin into the blood plasma.
Caused when complement molecules male the PM of donated RBCs leaky.
Rh Blood Group
Named for the Rh antigen called Rh factor.
People who have Rh antigens are Rh Pos.
People who lack Rh antigens are Rh neg.
Platelets Plug Formation
- Platelet adhesion: platelet stick to parts of damaged blood vessels
2: Platelet releases reaction: platelet become activated and release content of their vesicles. - Platelet aggregation: allows for ADP and tromboxane A2 to recruit more platelets to gather
- Platelet plug: where enough platelet accumulate to form a mass.
