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