Chapter 19: Blood Flashcards
Functions of Blood
- Transportation
- Regulation
- Protection
Blood Function: Transportation
- transports oxygen and nutrients to body cells
- transports wastes to lungs and kidneys for excretion
- transports hormones from endocrine organs to target organs
Blood Function: Regulation
- maintains pH using buffers
- maintains body temperature by absorbing and distributing heat
- maintains adequate fluid volume in circulatory system
What are the three types of plasma proteins that are found in plasma?
- Albumin
- Globulins
- Fibrinogen
Albumin
- (60%) major contributors to the osmotic pressure of plasma
- important in the transport of fatty acids, thyroid hormones, some steroid hormones and other substances
- produced by the liver
3 Types of Globulins
- Alpha
- Beta
- Gamma
Function of Alpha/Beta Globulins
- are transport proteins, carrying things like metal ions (iron and copper for example) and lipid hormones.
- Produced by the liver
Gamma Globulins
- Antibodies released by plasma cells during immune response that attack foreign proteins and pathogens
- Not produced by the liver
Fibrinogen
• (~4%) functions in clotting:
◦ under certain conditions, fibrinogen molecules will interact with each other forming large, insoluble strands of fibrin
• produced by the liver
Plasma
fluid component of blood (approx 55% of whole blood)
Plasma Compostion
- water (92%)
- Plasma Proteins (albumins, globulins, fibrinogen) (7%)
- Other Solutes (electrolytes, nutrients, wastes) (1%)
Give a normal range of blood volume in healthy humans
Adult male: 5-6 L
Adult female: 4-5 L
Hematology
Study of blood
Hematocrit
Percentage of blood volume composed of red blood cells
Differential WBC count
Percentage of each type of leukocyte
Hemolysis
Destruction of red blood cells
Complete blood count
Tests that screens for anemia and other infections, includes counts of RBC’s, WBC’s , platelets per microliter of whole blood , hematocrit, differential WBC count
Describe the formation of blood cells (hematopoiesis) and all terms discussed in lecture
check notes for chart
Hematopoiesis
Process of blood cell formation in bone marrow
What are the types of blood cells?
- Leukocyte
- Erythrocytes
- Platelets
Describe the function of each blood cell type
- Erythrocytes- transports O2 in blood
- Leukocytes- defends body against pathogens
- Platelets- contains enzymes and other substances important to the process of blood clotting and coagulation
Characteristics of RBC’s
- small in diameter
- cell has biconcave disc shape, anucleate & has no organelles
- average life span 120 days
- filled with Hemoglobin for gas transport
- contain spectrin and other proteins
- RBC diameters are larger than some capillaries
Erythropoiesis
Formation of RBC’s
What are the stages of Erythropoiesis ?
- Myeloid stem cell: transforms into proerythroblast
- Proerythroblast: divides many times, transforming into basophilic erythroblasts
- Reticulocytes: still contains small amounts of ribosomes
- Mature erythrocyte: in 2 days, ribosomes degrade , transforming into mature RBC
Regulation of Erythropoiesis
Maintains balance between RBC production and destruction
Too few RBC’s lead to
Tissue hypoxia
Too many RBC’s leads to
Increases blood viscosity
In what two ways are Erythropoiesis regulated ?
- Hormonal Control
2. Dietary Requirements
Erythropoietin (EPO)
Hormone that stimulates the production of RBC’s
How do hormones regulate Erythropoiesis?
- Erythropoietin (EPO) - hormone that stimulates formation RBC’s
- always small amount of EPO in blood to maintain basal rate
- Released by kidneys (some in liver) in response to hypoxia
hypoxia inducible factor (HIF)
- accumulation triggers the synthesis of EPO
- monitors oxygen levels in the blood
At low O2 levels, oxygen sensitive enzymes in the kidneys cannot degrade
Hypoxia-inducible factor (HIF)
How does dietary requirements regulate Erythropoiesis?
• amino acids, lipids and carbs
• Iron: available from diet
◦ 65% of iron is found in hemoglobin, rest is in liver, spleen and bone marrow
• Vitamin B12 and folic acid are necessary for DNA synthesis for rapidly dividing cells such as developing RBC’s
Reticulocytes
Immature RBC without a nucleus
Blood doping
Athletes remove, store and reinfuse RBC’s before an event to increase oxygen levels and increase stamina
Explain RBC turnover
- life span: 100-120 days
- RBCs cannot synthesize new proteins or grow or divide
- Old RBC’s become fragile & Hb starts to degenerate
- Can get trapped in smaller circulatory channels, especially in spleen
- Macrophages in spleen, liver, red bone marrow engulf & break down dying RBC’s
Hypoxia
Abnormal reduction of O2 delivered to tissues
Normoxia
Normal oxygen conditions
Anemia
Not enough healthy RBC’s to carry adequate oxygen to the body tissues
Symptoms: fatigue, dyspnea and chills
Polycythemia
Excessive numbers of RBC’s: increases blood viscosity causing sluggish blood flow
Name 7 types of anemias
- Hemorrhagic anemia
- Chronic hemorrhagic anemia
- Iron-deficiency anemia
- Pernicious anemia
- Renal anemia
- Aplastic anemia
- Hemolytic anemia
Hemorrhagic anemia
- rapid blood loss (ex: severe wound, heavy menstruation)
* treated by blood replacement
Chronic hemorrhagic anemia
• slight but persistent blood loss
◦ ex) hemorrhoids, bleeding ulcer
• primary problem must be treated to stop blood loss
Iron-deficiency anemia
- can be caused by hemorrhagic anemia, but also by low iron intake or impaired absorption
- RBC’s produced are called microcytes
- Treatment: iron supplements
Pernicious anemia
- autoimmune disease that destroys stomach mucosa that produces intrinsic factor (which is needed to absorb B12 which is needed to help RBC’s divide )
- Can also be caused by low dietary intake of B12
Renal anemia
• caused by lack of EPO
• Often accompanies renal disease
◦ kidneys cannot produce enough EPO
• Treatment: synthetic EPO
Aplastic anemia
- Destruction or inhibition of red bone marrow
- Can be caused by drugs, chemicals, radiation or viruses - usual cause unknown
- Treatment: short-term with transfusions, long-term with transplanted stem cells
Hemolytic anemia
• premature lysis of RBC’s
• Can be caused by:
◦ incompatible transfusions or infections
◦ hemoglobin abnormalities usually genetic disorder resulting in abnormal hemoglobin
▪ thalassemias and sickle-cell anemia
Thalassemias
• one globin chain is absent or faulty
• RBC’s are thin, delicate and deficient in hemoglobin
• Many subtypes that range in severity
◦ very severe cases may require monthly blood transfusions
Sickle cell anemia
• Hemoglobin S: mutated hemoglobin
◦ Only 1 amino acid is wrong in a globin beta chain of 146 amino acids
• RBC’s become crescent shaped when O2 levels are low
• Treatment: acute crisis treated with transfusions; inhaled nitric oxide
What are the three types of polycythemias?
- Polycythemia Vera
- Secondary polycythemia
- Blood doping
Polycythemia Vera
- bone marrow cancer leading to excess RBC’s
- Hematocrit may go as high as 80%
- Treatment: therapeutic phlebotomy
Secondary polycythemia
caused by low O2 levels (example: high altitude) or increased EPO production
Characteristics of Human Blood
- Average Temp: 38 degrees Celsius
- pH Slightly basic/alkaline (pH: 7.35 - 7.45)
- sticky and more dense than water (5x more viscous)
- consist of blood cells + fluid matrix (plasma)
Describe the structure and function of the hemoglobin molecule.
- Contains globulin and heme. Globulin is composed of 4 polypeptide chains: 2 alpha and 2 beta chains with 1 iron in each that binds to oxygen.
- Each heme can carry 1 02, 4 total.
- 1 heme pigment is bonded to 1 globulin chain: gives blood red color
Compare and contrast granulocytes and agranulocytes.
- agranulocytes contain no visible granules in their cytoplasm; lymphocytes and monocytes
- granulocytes contain visible granules in their cytoplasm; neutrophils, basophils and eosinophils
General Function of Neutrophils
- very phagoctyic
- kill microbes by process called respiratory burst
- denfinsin granules merge with phagosome: form spears that pierce holes in membrane of ingested microbe
3 Types of Lymphocytes
- T Lymphocytes (T Cells)
- B Lymphocytes (B Cells)
- Natural Killer Cells
B lymphocytes (B cells)
give rise to plasma cells, which produce antibodies
T lymphocytes (T cells)
act against virus- infected cells and tumor cells
Natural Killer Cells
kill cancer cells
Describe WBC circulation and movement
- Can migrate out of the bloodstream - diapedesis
- Have amoeboid movement
- Attracted to chemical stimuli (positive chemotaxis)
- Some are phagocytic: Neutrophils, Eosinophils and Monocytes
Reticulocyte Count
percentage of circulating reticulocytes
Normal = 038%
General Function of Basophils
- Contain histamine: dilates blood vessels (attracts WBCs to inflamed sites)
- Contain heparin: prevents blood clotting
- functionally similar to mast cells
General Function of Eosinophils
- attack large parasites (parasitic worms): release enzymes, digesting their surface
- excrete toxic compounds
- play a role in allergies & asthma
- control inflammation w/ enzymes that counteract inflammatory effects of neutrophils & mast cells
General Function of Monocytes
- leave circulation entering tissues and differentiate into macrophages
- actively phagocytic cells
- crucial against viruses, intracellular bacterial parasites and chronic infections
- secrete substances that activate lymphocytes to mount an immune response and fibroblast to injured area
What are the 3 types of WBC disorders?
- Leukemias
- Infectious mononucleosis
- Leukopenia
What are the 2 types of leukemias?
- Acute (quickly advancing) leukemia
2. Chronic (slowly advancing) leukemia
Leukemia
- cancerous condition involving overproduction of abnormal WBC’s (usually involve clones of single abnormal cell)
- Named according to abnormal WBC clone involved (myeloid leukemia involves myeloblast descendants and lymphocytic leukemia involves lymphocytes
Acute Leukemia
- quickly advancing
- derives form stem cells
- primarily affects children
Chronic Leukemia
- slowly advancing
- involves proliferation of later cell stages
- more prevalent in older people
What is Infectious mononucleosis?
-highly contagious viral disease (kissing disease)
caused by epstein-Barr virus
What is the result of infectious mononucleosis?
- results in high numbers of agranulocytes
- involve lymphocytes becoming enlarged
- Syptoms: tired, achy, chronic sore throat, low fever
- Run course with rest in 4-6 weeks
Leukopenia
- abnormally low WBC count
- can be drug induced
Describe the formation of human platelets.
- also known as thrombocytopoiesis, is regulated by thrompoietin
- formed in the myeloid line from megakaryoblast
- megakaryocytes sends cytoplasmic projections into lumen of capillary
- these projections break off into platelet fragments
- age quickly and degenerate in about 10 days
Describe the function of Platelets
- release important clotting chemicals
- form temporary platelet plug that helps seal breaks in blood vessels
- reduce size of break in vessel wall
hemostasis
- sequence of fast reactions for stoppage of bleeding
- requires clotting factors and substances released by platelets and injured tissues
What are the 3 steps in hemostasis?
- Vascular Spasm
- Platelet Plug Formation
- Coagulation (blood clotting)
What happens during Vascular Spasm?
- Vessel responds to injury with vasoconstriction
- most effective in smaller blood vessels
- reduces blood flow until other hemostatic mechanisms can be activated
What triggers vascular spasm?
- direct injury to vascular smooth muscle
- chemicals released by endothelial cells and platelets
- pain reflexes
What happens during Platelet Plug formation?
begins with attachment of platelets to sticky endothelial surfaces, to the basement membrane, to exposed collagen fibers and to each other. As they become activated, platelets release a variety of chemicals that promote aggregation, vascular spasm, clotting and vessel repair.
Explain what the following do during Platelet Plug formation.
- prostacyclins and nitric oxide
- ADP
- Von Willebrand Factor
- Serotonin and thromboxane A2
- prostacyclins and nitric oxide - prevent platelet sticking
- ADP - causes more platlets to stick and release their contents
- Von Willebrand Factor - helps to stabilize platelet-collagen adhesion
- Serotonin and thromboxane A2 - enhances vascular spasm and platelet aggregation
What happens during Coagulation?
- reinforces platelet plug with fibrin threads
- blood is transformed from liquid to gel - called clotting (coagulation)
- series of reactions use clotting factors (procoagulants), mostly plasma proteins
Describe how blood coagulation occurs and define the coagulation cascade as discussed in lecture: intrinsic, extrinsic and common pathways, the significance of vitamin K
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What are the 2 major types of disorders of hemostasis?
- Thromboembolic disorders
2. Bleeding disorders
What are bleeding disorders and name the 3 types?
- abnormalities that prevent normal clot formation
1. thrombocytopenia
2. impaired liver function
3. hemophelia
What are thromboembolic disorders and name the 3 types?
- results in undesirable clot formation
1. thrombus
2. embolus
3. embolism
thrombus
clot that develops and persists in unbroken blood vessel
-may block circulation, leading to tissue death
embolus
thrombus freely floating in bloodstream
embolism
embolus obstructing a vessel
thrombocytopenia
- deficient number of circulating platelets
- petechiae appear
- due to suppression or destruction of red bone marrow
- Treatment: transfusion of concentrated platelets
Impaired liver function
- inability to synthesize procoagulants (clotting factors)
- causes include vitamin k deficiency, hepatitis or cirrhosis
- liver disease can also prevent liver from producing bile, which is need to absorb fat and vitamin k
What are the 3 types of hemophilia?
- Hemophelia A - most common type due to factor VIII deficiency
- Hemophelia B - factor IX deficiency
- Hemophelia C - factor XI deficiency, milder
What are the symptoms and treatment of hemophilia?
- symptoms: prolonged bleeding, especially in joint cavities
- treatment - injections of genetically engineered factors
Describe clot retraction
tightening of the fibrin clot
- actin and myosin in platelets contract with 30-60 min.
- contraction pulls on fibrin strands, squeezing serum from clot
- draws rupture blood vessels edges together
- vessel is healing even as clot retraction occurs
Platelet-derived growth factor (PDGF)
released by platelets and stimulates the division of smooth muscle cells and fibroblasts to rebuild blood vessel wall during clot retraction
Vascular Endothelial growth factor (VEGF)
stimulates endothelial cells to multiply and restore endothelial lining during clot retraction
Describe Fibrinolysis
- dissolution of the clot
- process whereby the clot is gradually dissolved after repair is completed
- begins within 2 days and continues several days until clot is dissolved
- plasminogen, plasma protein that is trapped in clot, is converted to plasmin (fibrinolysin, a fibrin digesting enzyme
Describe factors that limit normal clot growth
- swift removal of clotting factors
- inhibition of activated clotting factors
. List the four general types of human blood
- A
- B
- AB
- O
Someone with type O- or O+ blood can donate and receive blood from
O- can receive: O-
O+ can receive: O+, O-
donate: to anyone, universal donor
Someone with type A- or A+ blood can receive and donate blood to
A- can receive: A-, O-
A+ can receive: A+, A-, O+, O-
A- can donate to: A-, A+, AB+, AB-
A+ can donate to: A+, AB+
Someone with type B- or B+ blood can receive and donate to
B- can receive: B-, O-
B+ can receive: B+, B-, O+, O-
B- can donate to: B-, B+, AB-, AB+
B+ can donate to: B+, AB+
Someone with with type AB- or AB+ blood can receive and donate blood to who
AB- can receive: AB-, B-, A-, O-
AB+ can receive: AB+, AB-, B+, B-, A+, A-, O+, O- (all blood types)
AB- can donate: AB-, AB+
AB+ can donate: AB+
antigen
- agglutinogen
- foreign protein that stimulates white blood cells to make antibodies
antibodies
- agglutinins
- immune systems molecules that attack cells with foreign antigens
agglutination
the clumping together in suspension of antigen-bearing cells, microorganisms, or particles in the presence of specific antibodies
Hemolytic Disease of a Newborn
- newborn baby is Rh + and mother is Rh -
- when the mother and the baby blood type does not match, the mother’s antibodies attack the baby.
Rh Factor
presence, or lack, of antigens on the surface of red blood cells that may cause a reaction between the blood of the mother and the fetus
if your blood has this protein, it is RH+, if not it is (-)
warfarin
- used for people prone to atrial fibrillation
- interferes with action of vitamin K
heparin
anticoagulant used clinically for pre- and postoperative cardiac care
venipuncture
Inscision into vein with needle to remove venous blood sample
arterial puncture
puncture of the radial, femoral, or brachial artery with the purpose of obtaining an arterial sample for testing pH, oxygen, carbon dioxide
hemophilia
a rare, inherited blood disorder in which the blood does not clot normally.
leukocytosis
increase in the # of leukocytes in blood
septicemia
Blood poisoning due to the presence of bacteria and/or their toxins in the blood.
jaundice
A result of liver disease, and it is yellowing of the skin.
positive chemotaxis
Movement of the leukocyte in the direction of the chemical trail released by damaged cells or other leukocytes
universal donor
- Type O blood
- A donor whose RBCs lack the antigens commonly attacked by recipient antibodies
universal recipient
Type AB (No antibodies in plasma)
procoagulants
- involved in the steps for transforming blood from a liquid to a gel
- helps blood to clot
anticoagulants
- dissolve blood clots
- act to prevent blood clots from forming. blood thinners
