Lecture 7 - Blood Flashcards
What is basic composition of blood 2 things
Plasma and formed elements
Basic function
Complex transport medium that performs pickup and delivery services for the body
Also heat regulating mechanism
What does blood transport
- Food substances (glucose, amino acids, lipids)
- Compounds formed from metabolism(urea, uric acid, creatine, lactic acid)
- respiratory gases( O2 and CO2)
- regulatory substances (hormones, enzymes)
Blood volume of young adult male
5L about 8% of body weight
Factors that affect blood volume
- age
- body type
- body fat (less fat= more blood)
- gender
- method of measurement
What is Hematocrit
Volume % of RBCs in whole blood (packed cell volume)
What is Buffy coat
WBCs and platelets that make up less than 1% of blood volume
What is Plasma
90% water 10% solutes
What proteins are in plasma
7% of plasma is proteins
- Albumins
- Globulins
- Fibrinogen
- Prothrombin
What other solutes are in plasma
Ions Nutrients Waste products Gases Regulatory substances
What are Leukocytes and the 5 types
They are WBCs 1 Neutrophils 2 Lymphocytes 3 Monocytes 4 Eosinophils 5 Basophils
Physical traits of plasma
- Liquid part of blood (matrix)
- clear, straw colored fluid
- made of 90% water 10% solutes
What do Albumins do
Expand blood volume
What do globulins do
Essential component of the immunity mechanism
What does fibrinogen do
Key role in blood clotting
Why is plasma essential to maintaining normal blood circulation (3 things)
1 Maintains blood viscosity
2 blood osmotic pressure
3 blood volume
What are Erythrocytes
RBCs
Physical description of Erythrocytes
- no nucleus
- tiny biconcave disk shape
- no ribosomes, mitochondria, other organelles
- shape can passively change as they forcibly pass through tiny capillaries
- made of primarily hemoglobin
What makes RBCs so flexible
Spectrin protein
What fraction of RBCs is hemoglobin
1/3 of RBC volume
What is most numerous of formed elements
RBCs
- in men RBC count = 5.5 million per mm3 of blood
- in women = 4.8 million per mm3 of blood
Function of Erythrocytes
Critical role in transport of O2 and CO2 and depends on hemoglobin
What is Carbonic anhydrase
Enzyme in RBC that catalyzes a reaction that joins C02 and H2O to form Carbonic acid
What does Carbonic acid do
Dissociates and generates bicarbonate ions, which diffuse out of the RBC and transport CO2 in the blood plasma
How much hemoglobin is in each RBC
Approximately 200 to 300 million molecules
What kind of protein is hemoglobin
A quaternary protein
What is oxyhemoglobin
Hemoglobin uniting with 4 oxygen molecules
- allows RBCs to transport oxygen where its needed
What is anemia
A decrease in number or volume of functional RBCs in a given unit of whole blood
How much O2 and CO2 molecules can 1 Hb molecule carry
4 O2
4CO2
Structure of hemoglobin
4 protein chains (globins) each with a heme group that each contain 1 Fe atom
What is the entire process of RBC formation called
Erythropoiesis
Where does formation of RBC begin
In red bone marrow ( flat bones )
What are some flat bones
Pelvis, sternum, cranium, ribs, vertebrae, scapula
How are RBCs formed
Begin in red bone marrow as hematopoietic stem cells and undergo several stages of development to become Erythrocytes ( takes about 4 days)
How many RBCs are created and destroyed each minute and day in adult
100 million / minute
200 billion / day
What mechanisms help balance number of cells formed against number cells destroyed
Homeostatic mechanisms
What is erythropoietin
A hormone released by kidneys
What does erythropoietin do
Detects low oxygen levels then stimulates bone marrow to accelerate its production of RBCs
What is feedback loop to decreased atmospheric oxygen
1 Sensor in kidney detects lower O2
2 Correction signal to increase erythropoietin
3 Effector increased number of RBC created in bone marrow
What is average life span of RBC
105 to 120 days
What happens to aged, abnormal or fragmented cells
Macrophage cells phagocytize them
What happens when hemoglobin is broken down during destruction of RBC
Amino acids, iron, and bilirubin are relaesed
Where are the macrophages that phagocytize located
In spleen and liver
What happens to globin after hemoglobin break down
It is converted into amino acids and used as energy source for protein synthesis
What happens to heme after break down of hemoglobin
It is further degraded into iron then stored or used to make more hemoglobin or bilirubin
What are the 4 Blood types
A, B, AB, O
What are agglutinogens
Antigens on RBCs membrane
What are antigens
Molecules that stimulate an immune response
What are agglutinins
Antibodies dissolved in plasma
What are antibodies
Specialized Y shaped protein that is produced to identify and neutralize specific antigens
Also called immunoglobulin
What is blood type named after
Antigen on the RBC
What antibodies are in blood type AB plasma?
None - known as universal recipients
What antigens and antibodies are in Type O blood and plasma?
No antigens on RBC + A &B antibodies in plasma
Known as universal donor
What happens when same antigen and antibody combine
They cause RBC to agglutinate (clump together)
What components of blood are in blood transfusions
Not whole blood
Just RBC
What is main concern with blood transfusions
Will antigens on the RBC of the donor react with antibodies in plasma of the recipient
When is universal donor or universal recipient not universal
If recipients plasma contains agglutinins other than anti-A or anti-B antibodies causing transfusion reaction
What is a transfusion reaction
When hosts antibodies attack donor RBC ->RBCs break apart -> Hb is released into blood stream-> overloads kidneys -> kidney failure
What are some symptoms of kidney failure
Fever, difficulty breathing, pink urine
What 3 steps are taken to make blood safe
- Typed (8 combos)
- Antibody screen test
- Cross-match test
What is cross-match test
Mix drop of donor and recipient blood to test for clumping
What are the 2 Rh types
Rh positive
Rh negative
What is Rh positive
Rh antigen is present on the RBC
What is Rh negative
RBCs have no Rh antigen present
When can anti-Rh antibodies appear in blood
In Rh negative blood if it has come in contact with Rh positive RBCs
What happens when Rh negative person get Rh positive blood
Recipient begins to make antibodies against the Rh antigen, which remains in blood
What is Erythroblastosis fetalis
- If Rh negative mother births Rh positive fetus the positive blood cells enter mother during birth.
- If mother becomes pregnant with another Rh positive fetus erythroblastosis fetalis can occur
- anti-Rh antibodies enter blood supply causing agglutination of RBCs
What are Leukocytes
WBCs
What are two categories of WBC
Granulocytes and agranulocytes
What are the 3 Granulocytes
Neutrophils
Eosinophils
Basophils
What are the 2 Agranulocytes
Lymphocytes
Monocytes
What % of WBC is Neutrophils
Approximately 65%
What type of cell is Neutrophils
Highly mobile and active phagocytic cells
What is a phagocytic cell
Cells that protect body by ingesting harmful foreign particles, bacteria, and dead or dying cells
What is diapedesis
Movement of WBC out of circulation and towards the site of injury
Are neutrophils capable of diapedesis
Yes
What are in neutrophil cytoplasmic granules
Lysosomes
What attracts Neutrophils and other phagocytic WBCs to infection site
Bacterial infections that produce inflammatory response causing release of chemicals from damaged cells (positive chemotaxis)
What % of WBC is Eosinophils
2 to 5 %
Where are there many Eosinophils
Lining of respiratory and digestive tract
Are Eosinophils good phagocytes
No they are weak
What are Eosinophils capable of ingesting
Inflammatory chemicals and proteins associated with antigen-antibody reaction complex
What is a main function of Eosinophils
Provide protection against infections caused by parasitic worms and allergic reactions
What % of WBC Is Basophils
0.5 to 1 %
Main function of Basophils
Cytoplasmic granules contain histamine and heparin
Are Basophil capable of diapedesis
Yes they are mobile and capable of diapedesis
What is histamine
Inflammatory chemical released by WBC as immune response to allergens
What is heparin
San anticoagulant
What % of WBC are Lymphocytes
25%
What are the 2 types of Lymphocytes
T Lymphocytes
B Lymphocytes
What do T Lymphocytes do
Directly attack an infected or cancerous cell
What do B Lymphocytes do
Produce antibodies against specific antigens
What % of WBC are Monocytes
3-8%
Structural aspects of monocytes
Largest WBC
- mobile and highly phagocytic (can engulf large bacterial organisms and viral-infected cells)
A function of Monocytes
Can migrate out of blood to enter tissue spaces as a macrophage
Where do granular and agranular leukocytes mature from
Undifferentiated hematopoietic stem cells (hemocytoblast)
Where do neutrophils, Eosinophils, Basophils, and a few lymphocytes and monocytes originate
Red bone marrow
Where do most Lymphocytes and Monocytes develope from
Hematopoietic stem cells in lymphatic tissue ( I.e. spleen, thymus)
What are thrombocytes
Blood platelets
3 important properties of platelets
Agglutination, adhesiveness, aggregation
What is aggregation
Attraction of particles
What is formation and life span of platelets
Formed in red bone marrow, lungs, and spleen by fragmentation of megakaryocytes
Life span 7 to 10 days
What are megakaryocytes
Cells in bone marrow responsible for making platelets
3 main functions of platelets
- Hemostasis
- Blood coagulation
- Secondary role in defending against bacterial attacks
What is Platelets role in homeostasis
Stoppage of blood flow in minor injuries
-if injury extensive blood-clotting mechanism is activated to assist
Are hemostasis of platelets and blood clotting the same
They are interrelated but seperate and distinct
4 steps in homeostasis platelet plug formation
- Damage to blood vessel causes vascular spasm which temporarily closes the vessel
- Within 1-5 seconds platelets adhere to damaged lining of the vessel forming the plug that helps stop the flow of blood into tissue
- Sticky platelets secrete ADP, fatty acids, and thromboxane, which aid the coagulation process
- If injury is extensive blood clotting mechanism is activated
What is a vascular spasm
Constriction of the smooth muscle closing vessel
How do sticky platelets secreting ADP, fatty acids and thromboxane aid coagulation
They cause vasoconstriction and platelet aggregation (clumping) at the site of injury
ADP activating platelets and starting aggregation forms what
White flakes
What is coagulation
Blood clotting
What is goal of coagulation
To stop bleeding and prevent loss of vital body fluid in swift and sure method
4 components critical to coagulation
- prothrombin
- Thrombin
- Fibrinogen
- Fibrin
What is stage 1 of coagulation
- production of prothrombin activator by:
- chemicals released from damaged tissue or chemicals present in blood
What is extrinsic pathway
Chemicals released from damaged tissue
What is intrinsic pathway
Chemicals present in the blood
What is stage 2 of coagulation
Conversion of prothrombin to thrombin
What is stage 3 of coagulation
- conversion of fibrinogen to fibrin and production of fibrin clot
Why are adequate calcium levels important in blood
Several of the clotting factors require calcium ions as a co-factor to make normal clotting occur
What prevents clotting
Perfectly smooth surface of endothelial lining in blood vessel ( nothing to adhere to)
- antithrombins
What are antithrombins
Substances in blood that oppose or inactivate thrombin, preventing thrombin from converting fibrinogen to fibrin
Ex. Heparin
What can cause clotting
- rough spot in the endothelium
- abnormally slow blood flow (sedentary life style, bed ridden)
What is the name for process of dissolving blood clot
Fibrinolysis
How is a clot dissolved
Plasmin hydrolyzes fibrin strands and dissolves the clot
What does Plasmin come from
Several substances released from damaged cells (ex. Thrombin, factor xii, t-pa lysosomal enzymes) convert plasminogen into active enzyme plasmin
Where does plasminogen come from
Normal blood plasma
What is given within first 6 hours of stroke
Tissue- plasminogen activator drug
- can improve blood flow and reduce after effects of stroke
How do many bacteria release anti clotting agents to overcome our defenses
The anti clotting agents activate plasminogen and disrupt formation of the blood clot
- used in medicine
What is Streptokinase
A plasminogen-activating factor made by streptococci bacteria
- can dissolve clots in the large arteries of heart
Big picture of blood plasma
Transports substances and heat around body linking all body tissue together
Blood tissue formed elements:
Blood cells and platelets
Big picture of RBCs
Assist in transport of O2 and CO2
Big picture of WBCs
Assist in defense mechanism of whole body
Big picture platelets
Prevent loss of the fluid that constitutes the internal environment
Blood is useless unless it
Transports, defends, and maintains balance
