Chapter 19 Flashcards
what are the functions of cardiovascular system
- transport gas, nutrients, hormones & metabolic wastes
- regulation of pH and ion composition of interstitial fluid (neutralizes lactic acid, controls Ca++ and K+ concentration) - buffers in the blood
- restriction of fluid loss at injury sites
- defence against toxins & pathogens
- stabilization of body temp (thermoregulation)
what are the components of Cardiovascular system:
1) blood - transport medium =4-6L, 38*C, pH (7.35-7.45)
2) heart - muscular pump that moves blood around the body
3) system of tubes/ vessels - arteries, veins, capillaries
What is body fluid compartments
total fluid 60% of body weight
intracellular fluid 40% of body weight
extracellular fluid 20% of body weight
* itnerstitial fluid 80% ECF
* plasma 20% ECF
What are the intracellular fluid & extracellular fluid
- 60% of our body weight is made up of water (40L in a 70kg male), water occupies two main compartments within the body:
1) intracellular fluid: fluid found within the cells of the body
2) extracellulra fluid (ECF) fluid outside of cells
- interstitial flud: the water surrounding cells within tissues
- plasma: thw ater found within the blood stream
- others: CSF, lymph, eye, synovial fluid, etc
*note that the electrolyte concentrations of all ECF is roughly the same
what is the plasma composition
= plasma proteins (7%), other solutes (1%), water (92%) - transports organics and inorganic molecules, formed elements and heat
1) plasma proteins
* albumins (60%) - major cobtriutors to somotic pressur eof plasm; transport lipids, steroid hormones
* globulins (35%) - transport ions, hormones, lipids; immune function
* fibrinogen (4%) - essential component of clotting system; can be converted to insoluble fibrin
* regulatory proteins (<1%) - enzymes, proenzymes, hormones
2) other solutes:
* electrolytes: normal extracellular fluid ion composition essential for vital cellular activities
-Ions contribute to osmotic pressure of body fluids (major plasma electrolytes are Na+, K+, Ca2+, Mg2+)
* other nutrients: used for ATP production, growth and maintenance of cells; include (fatty acids, cholesterol, glycerides), carnohydrates (primarily glucose) and amino acids
* organic wastes: carried to sites of breakdown or excretion; include urea, uric acid, creatinine, bllirubin, ammonlum ions
what is the plasma
Blood is a connective tissue = plasma + formed elements
* 55% of blood is plasma: composition similar to interstitial fluid with addition of dissolved proteins; plasma is the liquid matrix that supports and surrounds the blood cells
* although it does not contain collagen and elastin like other connective tissue matrices,
the blood plasma contains a number of dissolved proteins involved in…
1) transport and clooting
2) dissolved gases, electrolytes, and organic nutrients, platelets = cell fragments involved in clotting
* leukocytes = white blood cells (WBCs) involved in immune response
the kinds of dissolved plasma proteins
-
albumin: 60% of plasma protein
- the most abundant proeint int he plasma is involved in transporting lipid soluble susbtances (i.e. fattu acods ad steroid hrmones) in the blood, and is produced in the liver. Responsible for the majority of the blood colloid osmotic force - globulins: 35% of plasma protein: includes Antibodies (immunoglobulins) and transport globulins produced in the liver (transport vitamins, lipids, metal ions and hormones) e.g. lipoprotein (travelling around)
- antibodies: specialize proteins involved in immunity produced in lymph tissue
- fibrinogen and prothrombin: 4% of plasma protein - produced in the liver and are invovld in blood clotting. require vitamin K during ynthesis
- lipoproteins: produced in the liver and involved in transporting triglycerides and cholesterol in the blood (e.g. HDS & LDS)
- hormones and enzymes: specialized funcitons
- sources of most plasma proteins: liver
what are included in Gases (blood plsama)
: small amounts of oxygen and carbon dioxide are dissolved in the blood; however, Red blood cells (RBC) and bicarbonate play a more important role in gas transport
organic nutrients and metabolic wastes
- nutrients: monosaccharides, amino acids, and water soluble vitamins
- waste products such as lactate (glucose), urea (protein), uric acid (DNA/RNA), creatinine (creatine phosphate), and bilirubin (hemoglobin)
- electrolytes: ions such as Na+, K+, Ca++, H+, HCO3- and Cl-
what is hematocrit
% by volume of blood that is formed elements
male = 46 (higher average since they do have more skeletal muscles)
female = 42
what is erythyrocytes
(structure, what are required for the erythrocyte production, function and significance of shape)
structure: biconcave, no nucleus or membrane bound organelles, full of hemoglobin
erythrocyte production requires: Folic acid & vitamin B12
funcitons: transport O2 and CO2
significance of shape:
1) large surface area: volume ratio = increase - rapid RBC movement
2) form stacks 9ronleaux) that smoothly flow through narrow vessels
3) bend & flex through capillaries as narrow as 4 mM
the types of leukocytes
- neutrophlis: the most abundant phagocyte in the blood; contain extensive lysosomes
- eosinophils: destroy parastic worms & immune complexes
- basophils & mast cells: release histamine and heparin
- lymphocytes: involved in antibody production and the targeted specific immune response; only small amounts in blood the rest are in lymphatic tissues (nodes tonsils, and spleen)
- monocytes: can leave the blood steram and differentiate into powerful phagocytes called macrophages (fixed or free)
erythrocytes (RBC): transport oxygen and carbon dioxide
palatelets: anuclear cell-fragments formed from larger Megakaryocytes that are invovled in blood clotting
where are the blood cells produced from
all blood cells are formed in the bone marrow from a common blood stem cell, hemocytoblast
- once differentiated, mature cells enter the circulation
- some lymphocytes undergo additional maturation in the thymus gland (lymphoid tissue)
blood production 족보**
all from hemocytoblast
1. proerythroblast - polythromatic erythroblast - erythrocytes
2. myeloblast - progrnulocytes - basophil & eosinophil & neutrophil (granulocytes)
3. lymphoblast - lymphocyte (agranulocyte)
4. monoblast - monocyte (agranulocyte)
5. megakaryoblas - megakaryocyte - thromocytes (platelets)
what is hematopoiesis
= the process by which the formed elements of blood devleop is called hemopoesis (hematopoiesis). in adults, blood cells are formed in red bone marrow from pluripotent (multipotent) stem cells.
- they mature in bone marrow or lymphoid tissue
- born marrow harvesting for use in a bone marrow transplant
- multipotent stem cells = pluripotent stem cells: one stem cell becomes relevant cells in body (hemocytoblasts)
what is erythropoiesis
= the part of hematopoiesis that deals with the production of RBCs.
it increases when states of hypoxia (O2 deficiency) stimulate the kidneys to release the hormone erythropoietin (EPO)
- EPO circulates to the red marrow and speeds up the maturation and release of immature red cells
- EPO prod. can also be stim. by: throxine, grwoth hormone, testosterone (but not estrogen)
throxine = both work towards “growing tissues & maintaining tissues of your body
This triggers the level of RBC
what’s occuring during the evens in the red born marrow
developing RBCs absorb amino acids and Fe2+ from the bloodstream and synthesize new Hb molecules
1) cells destines to become RBCs fist differnetiate into prorythroblasts
2) proerythroblasts then differntiate into various stages of cells called erythroblasts, which actively synthesie hemoglobin.
- Erythroblasts are named according to total size, amount of hemoglobin present,a nd size and appearance of the nucleus
3) after roughly four days of differnetitation, the erythroblast, now called a normoblast, sheds its nucleus and becomes a reticulocyte, which contains 80% of the Hb of mature RBC
4) after two days in the bone marrow, reticulocytes enter the bloodsteram. After 24 hours in circulation, the reticulocytes complete their maturation and become indistinguishable from other mature RBCs
explain what reticulocytes are
the rate of erythropoiesis is measured by the number of immature RBCs (called reticulocytes or “retics”) in the peripheral circulation
- a low retic count (<0.5) indicates a low rate of reythropoiesis while an elevated rate (>2%) indicates a high rate of erythropoiesis
- the normal range is 1-2% of the RBCs being “retics”
- RBC production requires: amino acids, iron, B vitamins, and folic acid
- LOW RBC (or hemoglobin) production leads to fatigue, weakness and confusion due to lower O2 delivery (lack of oxygen)
brain is higly depends on oxygen
the protein chain of hemoglobin
4 poly peptide chains, each with a heme = pigment
the iron of each heme can bind to 1 oxygen molecule, O2
Hb + O2 <-> HbO2
deoxyhemoglobin <-> oxyhemoglobin
what is erythrocytes (RBCSs)
- 45% of the blood is RBCs. the percentage is called the hematocrit value is % of formed elements
- during differentiation RBCs synthesize larfe amounts of the protein hemoglobin. once hemoglobin production is complete, normoblasts eject their nucleus and organelles, and take ont he shape of a Biconcave Disk
- once differntiated, the RBC cannot replicate, synthesize proetin, or produce ATP from aerobic pathways, and only live for 120 days (mitochondria x blood)
- hemaglobin is a complex protein with four iron-containing heme groups. each heme group can reversibly bind to one oxygen molecule; therefore, each molecule of hemoglobin is called hemoglobin concentration
abnormalities of erythropoiesis
anemia: a condition of insufficient RBC or hemoglobin (quality or quantity)
- it is most often the result of low iron intake, hemolysis, autoimmune disease, blood loss, or lack of production in the bone marrow
polythemia: a condition of excess number of RBCs
- it occurs in response to hypoxia (natural “blood doping” is training at high alaltitude), shots of EPO (illegal “doping”), smoking (COPD, Chronic, obstructive pulmonary disease), or dehydration
plasma, buffy coat, hematocrit
- plasma: water, proteins, nutrient, hormones, etc.
- buffy coat: white blood cells, platelets
- hematocrit: red blood cells
What are the kinds of anemias
Iron deficiency anemia is the most common aneia in the US, and affects primarily menstruating women
- in the US, 20% of all women of childbeaering age have iron deficiency anemia, compared with only 2% of adult men (women have lower iron reserve than a man and sometimes poor diet, preganancy or being vegetarian contribute to loewr iron levels as well)
**hemorrhagic anemia **= the result of precipitous blood loss, and results in an equal decrease in Hct, Hgb content and RBC count
pernicious anemia - due to low vitamin B12 in diet (or low intrinsic factor, which is required for vit. B12 absorption)
sickle-cell disease (SCD) also called sickle-cell anemia, is an autosomal recessive disorder. A genetic defect in the primary DNA sequence leads to production of a faulty Hb beta chain, and RBCs that take on a rigid, sickle-shape
* sickling decreases the cell’s flexibility and results in a variety of complications; life expectancy is shortened
* treatments include: medications, blood transfusions & bone marrow stem cell replacement
pernicious anemia: Vit B12 is required for cells to uptake folic acid (req for DNA synthesis)
explain the erythrocyte life cycle
- low O2 levles in blood stimulate kidneys to produce erythropoletin
- erythropoletin levels rise in blood
- erythropoietin and necessary raw materials in blood promote erythropoiesis in red bone marrow
- new erythrocyles enter bloodstream; function about 120 days
- aged and damaged and blood cells are engulfed by macrophage of liver, spleen, and bone marrow; the hemoglobin is broken down
- raw materials are made avaible in blood for erythrocyte synthesis
- iron is bound to transterin and released to blood from liver as needed for erythropoiesis
from hemoglobin
- heme - iron stored as ferrittin, hemosiderin and bailrubin goes to liver
- the bailrubin is picked up from blood by liver, secreted into intestine in bile, metabolized to sterocoblin by bacteria and excreted in feces
- (small intestine) food nutrients, including amino acids, Fe, B12 and folic acid, are absorbed from intetine and enter blood `
Fe (iron) rritin = protein that stores most of Fe
Hemosiderin = complex of rest of iron
what does control the RBC production?
RBC production is controlled by the O2 saturation in the blood/ when this falls, the kidney released the hormone erythropoietin, which stimulates RBC synthesis in the bone marrow.
- RBC requires Fe, amino acids, vitamins B12 and folic acid
