The Blood Flashcards
What occurs when a cell becomes more specialized?
It becomes less capable of independent existence
What is the internal environment of the cardiovascular system?
Extracellular Fluids
- Interstital fluids
- Plasma
- Lymph
Intracellular Fluids
- Cytoplasm
What are the components of blood?
Formed Elements (Cellular Components)
- Erythrocytes, Leukocytes, Thrombocytes (Buffy Coat)
Plasma (Fluid Components)
- Water
- Plasma Proteins
- albumins, globulins, fibrinogen
- Other solutes
What is the hematocrit?
amount of Erythrocytes by % volume
What is the buffy coat?
Leukocytes+ Thrombocytes
Plasma proteins are part of the plasma (fluid) component of blood. What are the types of plasma proteins?
- Albumins: carry non-polar (non-water soluble) substances in the bloodstream
- Globulins: Part of the immune system
- Fibrinogen: Precursor molecule for Fibrin (Coagulant)
These proteins are LARGE and cannot exit the blood stream
Why do mean have a larger hematocrit?
Men have a higher metabolic rate b/c they have more muscle mass on average
-need more O2 so they have a higher % of erythrocytes to transport more O2 to the muscles
What are the Types of Leukocytes contained within the formed elements?
Granulocytes
- Neutrophils
- Eosinophils
- Basophils
Agranulocytes
- Lymphocytes
- Monocytes
What is hematopoiesis?
Formation of different blood cells from hemocytoblasts
What is a hemocytoblast?
A pluripotent stem cell that gives rise to Myeloid and Lymphoid stem cells during hematopoiesis
What are Myeloid and Lymphoid stem cells?
Derived from the Hemocytoblast during Hematopoiesis
Myeloid Stem Cells
- Erythrocytes, Megakaryocytes, neutrophils, eosinophils, basophils, monocytes
Lymphoid Stem Cells
- Lymphocytes (B+T Cells)
How does the bone marrow know what kinds of cells to create during hematopoiesis?
Growth Factors
- Erythropoietin: Erythrocyte production
- Thrombopoietin: Thrombocyte production
- Leukopoietin: Leukocyte production
What are the stages of blood cell formation?
Yolk Sac Stage
- Embryonic (3rd wk of pregancy-end of 2nd month)
Hepatic Stage
- Liver/Spleen production
- Beginning of 2nd month-just after birth
Myeloid Stage
- Beginning of 5th month of pregnancy-death
Which organ can tell what blood cells are needed in the blood stream and produce release factors in order to trigger production within the bone marrow?
The Kidneys filter the blood and receive 25% of the blood
What are the characteristics of erythrocytes?
- Biconcave disk for larger surface area
- Very flexible to fit into small capillaries
- Not a true cell b/c no nucleus
- Sacs of hemoglobin
- Last approx 4 months
What are the characteristics of Hemoglobin (Hb)?
- 4 Globins per Hemoglobin
- Each containing a Heme Group
- 4 globins/Hb = 4 Heme groups/Hb
- Each Heme group contains Fe2+
- Each Heme group can bind one O2
- 1 Hb can bind 4 O2’s
- 1 Globin can carry 1 CO2
~280 million Hemoglobin molecules per Erythrocyte
What substances are needed for the synthesis of Erythrocytes?
- Iron (Fe2+)
- Globulin
- Vitamin B12
- Erythropoietin
How is Erythropoietin regulated?
What occurs when an erythrocyte is destroyed?
Destroyed by Liver and Spleen and then recycled
Walk through the life and Death of an Erythrocyte.
What are the types of Leukocytes and their jobs?
Granulocytes
- Neutrophils: phagocytosis
- Eosinophils: Histaminases to break down histamine and anti-parasitic
- Basophils: secrete histamine and become mast cells when they leave the blood stream
Agranulocytes
- Lymphocytes: immunity
- Monocytes: phagocytosis and become macrophages when they leave the blood stream
How are pathogens contained?
Chemotaxis
- Chemotactic Factors (CF) are released by the injury site
- Margination: Leukocytes move toward Blood Vessel Wall following CF
- Pavementing: Leukocyte pushes against blood vessel wall
- Diapedesis: Leukocyte 1/2 in and 1/2 out
- Emigration: Leukocyte moves to highest concentration of CF (at injury site)
How to leukocytes move during chemotaxis? How long do leukocytes live?
Move using Ameboid Motion
Lifespan is 4-5 days
What are the characteristics of thrombocytes?
Cytoplasmic fragments shed from Megakaryocytes that reside in the Red Bone Marrow
- Formed as a result of growth factor thrombopoietin
- Biconvex disc
- Not a true cell (no nucleus or organelles)
- Clotting Factor
- Lifespan 5-9 days
What is Hemostasis and what occurs?
Control of Bleeding
After a Vascular injury:
- Vascular Spasm: smooth muscle contraction constricts blood vessel(s)
- Platelet Plug Formation
- Adhesion: platelets stick to wound site
- On the collagen of epithelial tissue
- Release Reaction: Clotting factors are released
- Aggregation: more platelets stick
- Adhesion: platelets stick to wound site
- Coagulation: Blood becomes “jellified” = Clot
What kind of feedback system is the release reaction step of the platelet plug formation during hemostasis?
Positive Feedback
- Clotting Factors initiate aggregation
- More platelets attracted to wound site
- These platelets release more clotting factors which attract more thrombocytes
How does coagulation (clotting) occur?
Two Pathways:
- Extrinsic Pathway: Clotting Factors released from injured tissue
- Intrinsic Pathway: Clotting Factors released from Blood
Both pathways lead to formation of Clotting Factor 10
- CF 10 Activate Prothrombinase
- Prothrombinase converts Prothrombin to Thrombin
- Thrombin converts Fibrinogen to Fibrin
- Fibrin forms the Fibrin Polymer+Platelet Plug = Clot
How does Fibrin+Thrombocytes form a clot?
Fibrin attaches to other fibrin to form a polymer. The Gaps are then filled in with platelets to form a plug.
What is syneresis?
Clot Retraction
- The wound site shrinks to reduce amount of tissue regeneration
What is Fibrinolysis?
Clot Dissolution
- Clotting Factor 12 is released by wound site with other CF’s
- CF12 works much slower than other CF’s
- After clot forms, CF12 initiates breakdown of clot
- Breaks down Fibrin Polymer
What are the types blood types and what makes them up?
ABO System
- Agglutinogens
- Membrane bound
- Glycoproteins that over surface of self-erythrocytes
- Rh System uses Agglutinogens too
- Agglutinins
- Plasma antibodies against non-self Agglutinogens
