Blood Circulation L 13 Flashcards
what are the 2 plasma proteins?
- Globulins
-) Alpha and beta globulins - transport lipids and fat-soluble vitamins
-) Gamma globulins - antibodies that function in immunity - Fibrinogen: helps in clotting after becoming fibrin
-) Serum - blood without fibrinogen
what is plasma volume?
regulatory mechanisms that maintain plasma volume to maintain blood pressure
what happens if fluid is lost?
Osmoreceptors in the hypothalamus cause the release of ADH from the posterior pituitary gland
-lose water = lose pressure source=heart has to pump harder to maintain pressure = need pressure for perfusion to keep things moving
what are the 3 functions of the circulatory system?
- Transportation
-respiratory gases, nutrients, wastes - Regulation
-hormonal and temp - protection
-immunity
septal defects are holes in …..
holes in interventricular or interatrial septa which allows blood to cross sides.
-Patent ductus arteriosus results from a failure of the foramen ovale to close after birth
what are erythrocytes? and their features
red blood cells,
a. Flattened, biconcave discs (disease: sickle cell)
b. Carry oxygen
c. Lack nuclei and mitochondria
d. Count - approximately 5 million/mm3 blood
e. Have a 120-day life span
f. Each contain about 280 million hemoglobin molecules
g. Iron heme is recycled from the liver and spleen; carried by transferrin in the blood to the red bone marrow
h. Anemia - abnormally low hemoglobin or RBC count
what are the 2 erythrocyte enzymes?
glycolytic enzymes and carbonic anhydrase
what are glycolytic enzymes and what do they do
-type of erythrocyte enzyme
- generate energy needed to fuel active transport mechanisms involved in maintaining proper ionic concentrations within cell
- Rely on glycolysis for ATP formation
what is carbonic anhydrase and what does it do?
-type of erythrocyte enzyme
- Critical in CO2 transport
- Catalyzes reaction that leads to conversion of metabolically produced CO2 into bicarbonate ion (HCO3-)
* Primary form in which CO2 is transported in blood
what are the 2 parts hemoglobin consists of?
- heme group
* Four iron-containing non-protein groups
* Each is bound to one of the polypeptides - Globin portion
* Protein composed of four highly folded polypeptide chains
erythropoiesis
-where does it occur?
-what removes old rbcs from circulation?
production of red blood cells(erythrocytes)
-rbcs survive 120 days
-SPLEEN removes old rbcs from circulation
-replaced at rate of 1-3 million rbcs/second
-occurs in bone marrow
- Pluripotent stem cells in red bone marrow differentiate into the different types of blood cells
Hematopoiesis
blood cell formation
Hematopoiesis
blood cell formation
a. Hematopoietic stem cells - embryonic cells that give rise to all blood cells
b. Process occurs in myeloid tissue (red bone marrow) and lymphoid tissue
c. As cells differentiate, they develop membrane receptors for chemical signals
Erythropoeisis
production of red blood cells
- red bone marrow produces 2.5 million RBCs/second
Regulation of erythropoiesis
-stimulated by:
-how long does process take?
all iron travels in blood bound to:
what hormone regulates iron homeostasis?
1) Process stimulated by erythropoietin from the kidneys that respond to low blood O2 levels
2) Process takes about 3 days
Most iron is recycled from old RBCs, the rest comes from the diet
1) Intestinal iron secreted into blood through ferroportin channels
2) All iron travels in blood bound to transferrin
3) Major regulator of iron homeostasis is the hormone hepcidin which removes ferroportin channels to promote cellular storage of iron and lowers plasma iron levels
Polycythemia
A disorder characterized by an abnormal increase in the number of red blood cells circulating in the blood (elevated hematocrit)
2 types primary and secondary
what are the 2 general types of polycythemia?
- primary polycythemia
* Caused by tumorlike condition of bone marrow
* Erythropoiesis proceeds at uncontrolled rate - Secondary polycythemia
* Erythropoietin-induced adaptive mechanism to improve blood’s oxygen-carrying capacity in response to prolonged reduced oxygen delivery to the tissues
* Occurs normally in people living at high altitudes
* Sometimes called relative polycythemia
hematocrit percentage under normal conditions
45%
hematocrit percentage under anaemia
30%
hematocrit percentage under polycythemia
70%
hematocrit percentage under dehydration
70%
more hematocrit makes blood more
viscous
anemia is characterized by:
causes:
low hematocrit
- Nutritional anemia
- Pernicious anemia
- Aplastic anemia
- Renal anemia
- Hemorrhagic anemia
- Hemolytic anemia
Platelets
- clot blood with ….
- have nuclei?
-Lifespan?
-how many? - removed from circulation by?
-clot blood with fibrinogen
-smallest
-dont have nuclei
-5-9 day lifespan
- release serotonin that stimulates vasoconstriction
- Count: 130,000 to 400,000/mm3 blood
* Thrombocytes
* Cell fragments shed from megakaryocytes
- Have organelles and cytosolic enzymes for generating energy and synthesizing secretory products
- High concentrations of actin and myosin
* Remain functional for an average of 10 days
* Removed from circulation by tissue macrophages
* Do not leave blood as WBCs do
- About ⅓ are stored in blood-filled spaces in spleen
- Released when needed by sympathetically induced splenic contraction
* Thrombopoietin
- Hormone produced by liver increases number of megakaryocytes and therefore increases platelet production
Leukocytes
- have nuclei and mitos?
- how many?
2 main categories :
white blood cells
- HAVE nuclei AND mitos
-Move in amoeboid fashion
- Diapedesis - movement through the capillary wall into connective tissue
- Count - approximately 5000 to 9000/mm3 blood
-. Types of leukocytes
1) Granular leukocytes: neutrophils, eosinophils, and basophils
2) Agranular leukocytes: monocytes and lymphocytes
What are the 3 granular leukocytes? Neb
neutrophils, eosinophils, basophils
What are the 2 agranular leukocytes?
lymphocytes and monocytes
Neutrophils
A granular type of white blood cell(leukocyte) that engulfs invading microbes
- Phagocytic specialists* Release web of extracellular fibres called neutrophil extracellular traps (NETs) that contain bacteria-killing chemicals
- Can also destroy bacteria by phagocytosis
- Functions
- First defenders on scene of bacterial invasion
- Very important in inflammatory responses
- Scavenge to clean up debris
Eosinophils
-granular or agranular
-what does it fight and kill?
-involved in what type of reaction?
a granular leukocyte that secretes chemicals that fights parasites, involved in allergic reactions
- Increase in circulating eosinophils (eosinophilia) is associated with
- Allergic conditions such as asthma and hay fever
- Internal parasite infestations, such as worms
- Attach to worm and secrete substances to kill it
Basophils
granular leukocyte
-release histamine and heparin
-involved in allergic reactions
- Least numerous and most poorly understood of the leukocytes
- Quite similar structurally and functionally to mast cells
- Synthesize and store
- Histamine
- Release is important in allergic reactions
- Heparin
- Speeds up removal of fat particles from blood after fatty meal
- Can also prevent clotting of blood samples drawn for chemical analysis
- Used extensively as anticoagulant drug
monocytes
agranular leukocyte
-transformed into macrophages
- Emerge from bone marrow while still immature and circulate for day or two before settling down in various tissues in body
- Mature and enlarge in resident tissue and become known as macrophages
- Life span can range from several months to years
lyphocytes
agranular leukocytes
-B lymphocytes(transformed into plasma cells that secrete antibodies
-T lymphocytes(cells)(responsible for cell-mediated immunity)
Lymphocytes
-what are the 2 types
-where do they each form?
-what do they each attack?
lifespan
B and T
The two types of white blood cells that are part of the body’s immune system
B lymphocytes form in the bone marrow
- release antibodies that fight bacterial infections;
T lymphocytes
- form in the thymus and other lymphatic tissue and
- attack cancer cells, viruses, and foreign substances.
- Provide immune defense against targets for which they are specifically programmed
- Live about 100 to 300 days
- Two types of lymphocytes
- B lymphocytes
- Produce antibodies
- Responsible to antibody-mediated or humoral immunity
- T lymphocytes
- Do not produce antibodies
- Directly destroy specific target cells by releasing chemicals that punch holes in the victim cell (cell-mediated immunity)* Target cells include body cells invaded by viruses and cancer cells
Red Blood Cell Antigens and Blood Typing
- Antigens are found ?
- Antibodies are secreted by ? In response to?
- ABO system: antigens on ……..
3 types:
1. Antigens: found on the surface of cells to help immune system recognize self cells
- Antibodies: secreted by (B) lymphocytes in response to foreign cells
- ABO system: antigens on erythrocyte cell surfaces
a. Type A - has the A antigen
b. Type B - has the B antigen
c. Type AB - has both the A and B antigens
d. Type O - has neither the A nor the B antigen
blood group types
-form of passive immunity
- ABO blood types are named for presence of antigens on surface of erythrocytes
- Type A has A antigens and anti-B antibodies
- Type B has B antigens and anti-A antibodies
- Type AB has both A and B antigens and no antibodies related to the ABO system
- Type O does not have A or B surface antigens and both anti
-A and anti-B antibodies
transfusion reaction
reaction of the body to a transfusion of blood that is not compatible with its own blood
-If a person receives the wrong blood type, antibodies bind to erythrocytes and cause agglutination.
Universal blood donor
o
Universal blood recipient
ab
Rh factor
-what is it?
-what does RH + and Rh- mean?
-what is Erythroblastosis fetalis? when does it occur?
Refers to the presence or absence of the Rh antigen on red blood cells.
- Rh-positive individual has Rh factor
- Rh-negative individual lacks Rh factor
- Erythroblastosis fetalis (hemolytic disease of the newborn)blood disorder that occurs when the blood types of a mother and baby are incompatible
- Occurs when Rh-negative mother develops antibodies against the erythrocytes of an Rh-positive fetus
- Approximately 12 other minor human erythrocyte antigen systems
heart murmur
an abnormal sound from the heart produced by defects in the chambers or valves(abnormal blood flow in heart)
-caused by defective heart valves
mitral stenosis
Mitral valve calcifies and impairs flow between left atrium and ventricle.
- may result in pulmonary hypertension
incompetent valves are valves that:
caused by:
-most common cause of chronic mitral regurtitation:
do not close properly
-cause: damaged papillary muscle
-mitral valve prolapse is most common cause of chronic mitral regurgitation
-mitral=bicuspid=left
cardiac cycle
A complete heartbeat consisting of contraction and relaxation of both atria and both ventricles
a. Repeating pattern of contraction and relaxation of the heart.
b. Systole: contraction of heart muscles
c. Diastole: relaxation of heart muscles
end-diastolic volume
total volume of blood in the ventricles at the end of diastole
End-systolic volume
the amount of blood left in the left ventricle after systole (1/3 of the end-diastolic volume
Pressure Changes During the Cardiac Cycle
- Ventricles begin contraction, pressure rises, and AV valves close (lub); isovolumetric contraction
- Pressure builds, semilunar valves open, and blood is ejected into arteries.
- Pressure in ventricles falls; semilunar valves close (dub); isovolumetric relaxation
- Dicrotic notch - slight inflection in pressure during isovolumetric relaxation
- Pressure in ventricles falls below that of atria, and AV valve opens. Ventricles fill.
- Atria contract, sending last of blood to ventricles