Chapter 18: Blood Powerpoint Flashcards
The circulatory system consists of what 3 things?
heart, blood vessels, and blood
The cardiovascular system refers only to the _____ and __________
heart and blood vessels
Define hematology
The study of blood and blood disorders
What are the 3 functions of the circulatory system?
Transport, protection, and regulation
What does the circulatory system transport?
O_2, CO_2, nutrients, wastes, hormones, and stem cells
How does the circulatory system provide protection?
Hemostasis and immune system
How does the circulatory system provide regulation?
Fluid balance, stabilizes pH of ECF, and temperature control
Adults have _ to _ L of blood (Average _L)
4;6; (5)
What type of tissue is blood?
A liquid connective tissue
What two things make up blood?
Plasma and formed elements
Define plasma
The extracellular matrix of blood
Define formed elements in blood
Blood cells and cell fragments
What are the 7 types of formed elements?
Erythrocytes, platelets, neutrophils, eosinophils, and basophils, lymphocytes, and monocytes
What are the two types of leukocytes?
Granulocytes and agranulocytes
What are the 3 types of granulocytes?
Neutrophils, eosinophils, and basophils
What are the 2 types of agranulocytes?
Lymphocytes and monocytes
Define erythrocytes
red blood cells (RBCs)
Define platelets
cell fragments
Define leukocytes
White blood cells (WBCs); there are 5 types
Define hematocrit
The percentage by volume of RBCs in your blood
When you centrifuge blood to separate its components, _______ are heaviest and settles to the bottom first.
erythrocytes
Erythrocytes make up about __% of total blood volume
45%
White blood cells and platelets make up ___% of blood volume
1%
White blood cells and platelets create a ____ coat
buffy
Plasma makes up ____% of blood volume
55
Define plasma
The liquid portion of blood
Define serum
Plasma without fibrinogen
What’s the difference between plasma and serum?
Plasma has fibrinogen, serum doesn’t
What are the 3 major categories of plasma proteins?
Albumins, globulins, and fibrinogen
What is the smallest and most abundant type of plasma protein?
Albumins
Plasma proteins are formed by the ____, except for gamma globulins which are produced by _____ _____.
liver; plasma cells
Describe the functions of albumins
Functions in maintaining osmotic pressure and transports hydrophobic substances; aids in filtration and reabsorption.
Describe the functions of the 3 different types of globulins
Alpha and beta globulins: transport hydrophobic substances
Gamma globulins = antibodies
Describe the functions of fibrinogen
Fibrinogen can be converted to Fibrin (blood clot)
What are the components of blood plasma?
Nitrogenous compounds; nutrients; dissolved water, carbon dioxide, and nitrogen; and electrolytes
What kinds of nitrogenous compounds can be found in blood plasma?
Free amino acids and nitrogenous wastes (urea)
What kinds of nutrients can be found in blood plasma?
Glucose, vitamins, fats, cholesterol, phospholipids, and minerals
True or false: very little oxygen, nitrogen, and carbon dioxide are dissolved into plasma
True
There is almost no ________ in plasma
nitrogen
Describe the role of carbon dioxide in plasma
A small amount is dissolved in plasma; some is carried by plasma proteins or hemoglobin, and most converted to a cation and anion (so hydrophilic)
Oxygen must be _____ in plasma
carried
Define viscosity
Resistance of a fluid to flow, resulting from the cohesion of its particles
Whole blood ___ to ___ times as viscous as water
4.5 to 5.5
Plasma is ___ times as viscous as water
2.0
Define the osmolarity of blood
The total molarity of those dissolved particles that cannot pass through the blood vessel wall
What is optimum osmolarity?
Regulation of sodium ions, proteins, and red blood cells
Define hypoproteinemia and what it’s caused from
The deficiency of plasma proteins, typically from extreme starvation, liver or kidney disease, or severe burns
Define Kwashiorkor and what it’s caused by
A disorder found in children with severe protein deficiency characterized by thin arms and legs and swollen abdomen. Patients are fed cereal once weaned.
Adults produce ____ billion platelets, ____-____ billion RBCs, and ____ billion WBCs every day
400; 100-200; 10
Define hematopoiesis
Production of blood, especially its formed elements
What produces blood cells
Hemopoietic tissues
The _____ _____ produces stem cells for the first blood cells, which then colonize fetal bone marrow, liver, spleen, and thymus
yolk sac
Adults produce blood cells primarily in what?
Red bone marrow
True or false: Red bone marrow produces all seven formed elements
True
Pluripotent stem cells (PPSC) in red bone marrow are also called what?
Hemocytoblasts or hemopoietic stem cells
Define a colony-forming unit
Specialized stem cells only producing one class of formed element of blood
What are the two main functions of RBCs/ erythrocytes?
1) Carry oxygen from lungs to cell tissues
2) Pick up carbon dioxide from tissues and bring to lungs
Insufficient RBCs can cause death in minutes due to what?
lack of oxygen to tissues
Describe the anatomy of erythrocytes
Shape is described as biconcave discs with thick rims. They’re flexible and can change shape, and they have no nucleus or organelles
Blood type is determined by what two things?
Surface glycoproteins and glycolipids
What do cytoskeletal proteins do in RBCs?
They give membrane durability and resilience; they’re able to stretch and bend as squeezed through small capillaries
What is a major function of RBCs?
Gas transport
Where can you find hemoglobin (hb) in the body?
In the cytoplasm of a RBC
How many hemoglobin molecules are in one RBC?What does hemoglobin do?
There are 280 million hemoglobin molecules in one RBC
Aids in oxygen delivery to tissue and carbon dioxide transport to lungs
Carbonic anhydrase (CAH) is found where?
In the cytoplasm of RBCs
Carbonic anhydrase (CAH) in RBCs produces _______ acid from CO2 and water
carbonic
Carbonic anhydrase (CAH) in RBCs play a big role in ____ transport and ____ balance
gas; pH
Each hemoglobin molecule consists of what?
4 protein chains (globins) and 4 heme groups
Adult HB has two ____ and two ____ chains
alpha; beta
Fetal Hb contains two ____ and two ____ chains
alpha; gamma
What do globins do in blood?
Globins bind CO_2 (5% of CO_2 in blood)
Define heme groups (what do they do?)
Nonprotein moiety (red-colored pigment) that binds O_2 to ferrous ion (Fe) at its center
Oxygen loading in lungs produces _______, which is bright red
Oxyhemoglobin (ruby red)
Oxygen unloading in tissues produces ______, which is dark red
deoxyhemoglobin (also called reduced hemoglobin)
During CO2 loading in tissues, what happens to the CO2?
20% of CO2 in blood binds to Hb, which creates carbaminohemoglobin
RBC count and hemoglobin concentration indicate amount of ______ blood can carry
oxygen
Why do women typically have less erythrocytes and hemoglobin?
1) Androgens stimulate RBC production
2) Women have periodic menstrual losses
3) Hematocrit is inversely proportional to percentage of body fat
Define erythropoiesis
RBC production
About _____ million RBCs are produced per second.
The average lifespan of an RBC is about ____ days
The development of an RBC takes __ to __ days
1 million; 120; 3 to 5
What forms colony-forming units?
Pluripotent/hemopoietic stem cells
The first committed cell is called the ________________ and has receptors for _________ from kidneys
erythrocyte colony-forming unit; erythropoietin (EPO)
What do erythroblasts (normoblast) do?
Multiply and synthesize hemoglobin
Sometimes the nucleus of an erythrocyte is discarded to form a ________
reticulocyte
What are reticulocytes named for, and what percentage of RBCs do they make up?
Named for their fine network of endoplasmic reticulum
0.5% to 1.5% of circulating RBCs are reticulocytes
Describe the role of iron in the body; how is it lost and how much do you need?
-Key nutritional requirement
-Lost daily through urine, feces, and bleeding
-Men 0.9 mg/day and women 1.7 mg/day
-Low absorption rate of iron requires consumption
of 5 to 20 mg/day
Name the two types of dietary iron and explain how they’re absorbed from our food
Two kinds: ferric (Fe^(3+) ) and ferrous (Fe^(2+) )
1) Stomach acid converts Fe^(3+) to absorbable Fe^(2+)
2) Then, gastroferritin binds Fe^(2+) and transports it to small intestine
3) It’s then absorbed into blood and binds to transferrin for transport to bone marrow, liver, and other tissues
Name 2 cofactors for enzymes synthesizing hemoglobin
Vitamin C and copper
Describe how negative feedback control aids in erythrocyte homeostasis
1) Drop in RBC count causes hypoxemia detected by kidney
2) Kidney production of erythropoietin stimulates bone marrow
3) RBC count increases in 3 to 4 days
What are some stimuli for increasing erythropoesis?
1) Low levels O_2 (hypoxemia)
2) High altitude
3) Increase in exercise
4) Loss of lung tissue in emphysema
Describe RBC death and disposal
1) RBCs rupture (hemolysis) in narrow channels of spleen and liver
2) Macrophages mainly in spleen but also in liver help digest:
2a) Globins hydrolyzed into amino acids
2b) Iron removed from heme and recycled
2c) Heme pigment excreted
3) Heme pigment converted to biliverdin (green)
4) Biliverdin converted to bilirubin (yellow)
5) Liver removes bilirubin (& biliverdin) and secretes into bile
6) Bile released into small intestine
7) Bacteria of large intestine convert pigments into urobilinogens
Define polycythemia
An excess of RBCs
Describe the 2 types of polycythemia
1) Primary polycythemia (polycythemia vera): The overproduction of erythropoietic cell line in red bone marrow.
2) Secondary polycythemia: From dehydration, emphysema, high altitude, or physical conditioning
What are the dangers of polycythemia?
It causes increased blood volume, pressure, and viscosity, all of which can lead to embolism, stroke, or heart failure
What are the 3 main causes of anemia?
1) Inadequate erythropoiesis or hemoglobin synthesis
2) Hemorrhagic anemias from bleeding
3) Hemolytic anemias from RBC destruction
Name 3 potential causes of inadequate erythropoiesis/ hemoglobin synthesis
Kidney failure
Iron-deficiency anemia
Pernicious anemia
What are the 3 potential consequences of anemia? (long answers)
1) Tissue hypoxia and necrosis
Typically the patient is lethargic; shortness of breath; necrosis of brain, heart, or kidney
2) Blood osmolarity is reduced, producing tissue death
3) Blood viscosity is low
Pressure drops and heart races; cardiac failure may ensue
Describe sickle-cell disease
1) Hereditary defect that occurs mostly among people of African descent
2) Caused by recessive allele that modifies structure of Hb (makes HbS)
- Differs only on one amino
- HbS does not bind oxygen well
- RBCs become rigid, sticky, pointed at ends
- Clump together and block small blood vessels
- Can lead to kidney or heart failure, stroke, joint pain, or paralysis
Blood types are based on interactions between ______ and ______
antigens and antibodies
Describe antigens
- Complex molecules on surface of cell membrane that activate an immune response
- “Antibody generating”
- Antigens on the surface of the RBC are the basis for blood typing
Describe antibodies
- Proteins (gamma globulins) secreted by plasma cells
- Part of immune response to foreign matter
- Forms antigen–antibody complexes
Describe agglutination
Antibody molecule binding to antigens causes clumping of red blood cells
Human blood groups have over ____ different antigens on RBC membranes and at least ____ different blood groupings
500; 100
We typically use what two types of blood grouping? Why?
Typically use the ABO blood grouping and the Rh blood grouping
This is because these cause the most severe transfusion reactions
Your ABO blood type is determined by presence or absence of _______ on RBCs
antigens (agglutinogens)
Blood type A person has ___ antigens
A
List the 2 different types of antibodies (agglutinins) and when they form
Anti-A and anti-B
Appear 2 to 8 months after birth; maximum concentration by 8-10 years of age
True or false: You do not form antibodies against your antigens
True
True or false: Each antibody can attach to several foreign antigens on several different RBCs at the same time, leading to agglutination
True
Agglutination and the RBO group is responsible for what?
Responsible for mismatched transfusion reaction:
1) Agglutinated RBCs block small blood vessels, hemolyze, and release their hemoglobin over the next few hours or days
2) Hb blocks kidney tubules and causes acute renal failure
Describe the universal donor
- Type O; the most common blood type
- Lacks RBC antigens
- Donor’s plasma may have both antibodies against recipient’s RBCs (anti-A and anti-B)
- May give packed cells (minimal plasma)
Describe the universal recipient
- Type AB+: rarest blood type
- Lacks plasma antibodies; no anti-A or anti-B
Describe the Rh groups
- Rh (C, D, E) agglutinogens discovered in rhesus monkey in 1940
- Rh D is the most reactive and a patient is considered blood type Rh^+ if having D antigen (agglutinogens) on RBCs
Describe anti-D antibodies in blood
- Anti-D antibodies not normally present
- Rh^− individuals must be exposed to Rh^+ blood
- Hemolytic disease of the newborn (HDN) can occur if Rh^− mother has formed antibodies and is pregnant with second Rh^+ child
- Anti-D antibodies can cross placenta
What is the solution to the anti-D antibody problem in fetuses?
- Prevention: RhoGAM given to pregnant Rh^− women
- Binds fetal antigens in her blood so she will not form anti-D antibodies
Describe the form and function of leukocytes
- Least abundant formed element
- 5,000 to 10,000 WBCs/μL
- Protect against infectious microorganisms/pathogens
- Spend only a few hours in the bloodstream before migrating to connective tissue
- Retain their organelles and nucleus
Describe granules in leukocytes
- All WBCs have lysosomes called nonspecific granules
- Granulocytes (some WBCs) have specific granules that contain enzymes and other chemicals employed in defense against pathogens
Describe neutrophils (type of granulocyte)
- 60% to 70% of granulocytes
- Polymorphonuclear leukocytes
- Aggressively antibacterial
Describe eosinophils (type of granulocyte)
- 2% to 4%
- Increased numbers in parasitic infections and allergies
- Release enzymes to destroy large parasites
Describe basophils (type of granulocyte)
-Less than 1%)
-Secrete histamine (vasodilator): speeds flow of blood to an injured area
Secrete heparin (anticoagulant): promotes the mobility of other WBCs in the area
Describe the two types of lymphocytes (type of agranulocyte)
- 25% to 33%)
- T-Cells (T-lymphocytes)
- B-Cells (B-lymphocytes): Transforms into plasma cells that secrete antibodies
Describe monocytes (type of agranulocyte)
- 3% to 8%
- Increased numbers in viral infections and inflammation
- Leave blood stream and transform into macrophages or dendritic cells
Define leukopoiesis
Production of white blood cells
Describe hemopoietic stem cells (HSCs) (a.k.a. hemocytoblast or pluripotent stem cells)
Differentiate into a particular colony-forming unit; each colony-forming unit develops into a particular type of WBC
Why do circulating WBCs only spend a few hours in the bloodstream?
They migrate to connective tissue
Describe leukopenia, its causes, and its effects
Defined as a low WBC count: below 5,000 WBCs/μL
Causes: radiation, poisons, infectious disease
Effects: elevated risk of infection
Describe leukocytosis and its causes
High WBC count: above 10,000 WBCs/μL
Causes: infection, allergy, disease
Define leukemia
Cancer of hemopoietic tissue usually producing a very high number of abnormal, circulating leukocytes
What is included in the complete blood count (CBC)?
1) Hematocrit
2) Hemoglobin concentration
3) Total count for RBCs, reticulocytes, WBCs, and platelets
4) Differential WBC count
5) RBC size and hemoglobin concentration per RBC
Define hemostasis
The stopping of bleeding
Define hemorrhage
excessive bleeding
What are the 3 hemostatic mechanisms?
Vascular spasm
Platelet plug formation
Blood clotting (coagulation)
True or false: Platelets play an important role in all three hemostatic mechanisms
True
Define platelets (thrombocytes) and a normal platelet count
Small fragments of stem cells
Normal platelet count—130,000 to 400,000 platelets/μL
List the functions of platelets
1) Secrete vasoconstrictors that help reduce blood loss
2) Stick together to form platelet plugs to seal small breaks
3) Secrete procoagulants or clotting factors to promote clotting
4) Initiate formation of clot-dissolving enzyme
5) Chemically attract neutrophils and monocytes to sites of inflammation
6) Internalize and destroy bacteria
7) Secrete growth factors that stimulate mitosis to repair blood vessels
Describe thrombopoiesis
Stem cells (that develop receptors for the hormone thrombopoietin) eventually become megakaryocytes
Describe megakarocytes
- Live in bone marrow adjacent to blood sinusoids
- Long tendrils of cytoplasm (proplatelets) protrude into the blood sinusoids and splits off
Platelets circulate freely for __-__ days and 40% of them are stored in the _____
5-6; spleen
Describe the vascular spasm mechanism of hemostasis
- Vasoconstriction of a broken vessel
- Most immediate protection against blood loss
- Caused by pain receptors, smooth muscle injury, or platelets release serotonin (vasoconstrictor)
Describe platelet plug formation
- Intact vessels have a smooth endothelium coated with prostacyclin (platelet repellant)
- Broken vessel exposes collagen
- Platelet pseudopods stick to the collagen and to each other
- Pseudopods contract - draw together a platelet plug
- Platelets degranulate releasing chemicals that attracts more platelets
- Positive feedback cycle until break is sealed
Describe coagulation
- The last and most effective defense against bleeding
- Conversion of fibrinogen into insoluble fibrin threads (framework of clot)
- Procoagulants (clotting factors) in plasma; activate one factor and it will activate the next to form a reaction cascade
- Prothrombin activator converts prothrombin to thrombin
- Thrombin converts fibrinogen into fibrin monomers
- Monomers covalently bind to form fibrin polymer
Describe the 2 pathways of coagulation
1) Extrinsic pathway Factors released by damaged tissues Faster 2) Intrinsic pathway Initiated by platelets Slower
Both pathways of coagulation require what?
Calcium
Platelet-derived growth factor, which is secreted by platelets and endothelial cells, does what?
Stimulates repair of damaged vessel
Define fibrinolysis
- Dissolution of a clot
- Plasmin is a fibrin-dissolving enzyme that breaks up the clot
What repels platelets to prevent inappropriate clotting?
Prostacyclin-coated endothelium
What happens to thrombin to prevent inappropriate clotting?
- Thrombin diluted and washed away by flowing blood
- Heart slowing in shock can result in clot formation
Define hemophilia
Family of hereditary diseases characterized by deficiencies of one factor or another
Define embolus and describe its consequences
- Anything that can travel in the blood and block blood vessels
- Infarction (tissue death) may occur – MI or stroke
- Pulmonary embolism: 650,000 Americans die annually of thromboembolism
Describe what may prevent clots
1) Vitamin K is required for formation of clotting factors (Coumarin, warfarin (Coumadin) are vitamin K antagonists)
2) Aspirin suppresses thromboxane A_2
3) Other anticoagulants discovered in animal research like:
- Medicinal leeches used since 1884 (hirudin)
- Snake venom from vipers (arvin)
Which mechanisms are used by the body to prevent inappropriate clotting?
Platelet repulsion caused by prostacyclin
Dilution of clotting factors
Presence of anticoagulants such as heparin and antithrombin