Blood Flashcards
Blood
- ## a connective tissue composed of cellular elements suspended in an extensive fluid matrix that circulates in the CV system
Composition of Blood
- plasma
Composition of Plasma
- water (92%)
- ion
- organic molecules
- trace elements and vitamins
- gases
Composition of Organic Molecules
- amino acids
- proteins (7%)
- glucose
- lipids
- nitrogenous waste
Gases in Blood
- CO2 and O2
Plasma Proteins
- primary difference between plasma and the interstitial fluid
- Albumins
- Globulins
- Fibrinogen
- Transferrin
Albumins
- multiple types
- source = liver
- major contributors to colloid osmotic pressure of plasma
- carriers for various substances
Globulins
- multiple types
- source = liver and lymphoid tissue
- clotting factors, enzymes, antibodies, carriers for various substances
Fibrinogen
- source = liver
- forms fibrin threads essential to blood clotting
Transferrin
- source = liver and other tissues
- iron transport
Cellular Elements
- Erythrocyte
- Leukocytes
- Thrombocytes
Leukocytes
- white blood cells Types 1. lymphocytes 2. monocytes (macrophage) 3. neutrophils 4. eosinophils 5. basophils (mast cell)
Hematocrit
- 40-45%
- the fraction of the total column occupied by RBC’s
Buffy Coat
- is WBC’s and platelets
- 1%
Plasma
- 55-60%
- pale white solution of electrolytes, plasma proteins, carbohydrates and lipids
Hematopoiesis
- production of blood cells
- lineage development guided by cytokines (cell signalling molecules)
- begins with pluripotent hematopoietic stem cell
- bone marrow
- in adults: pelvis, spine, ribs, cranium and proximal ends of long bones
Bone Marrow
- hidden within the bones of the skeleton
- consists of blood cells in different stages of development and supporting tissue known as stroma (mattress)
Cytokines
- proteins or peptides released from one cell that affect growth of activity in another cell
- cytokines involved in Hematopoiesis
1. Erythropoietin (EPO)
2. Thrombopoietin (TPO)
3. Leukopoiesis
4. Colony-stimulating factors (CSF), interleukins, stem cell factor
Erythropoietin (EPO)
- RBC production
- sites of production in kidney cells primarily
- stimulated by low O2
Thrombopoietin (TPO)
- produced in liver primarily
- influences growth or differentiation of megakaryocytic (platelets)
- thrombocyte (platelet) production (TPO)
Leukopoiesis
- Leukocyte (WBC) production (CSF’s)
Colony-Stimulating Factors (CSF)
- produced in endothelium and fibroblasts of bone marrow, leukocytes
- influences growth or differentiation of all types of blood cells; mobilizes hematopoietic stem cells
RBC’s Erythrocytes
- non-nucleated biconcave cells with diameter ~7.5um
- distinctive shape increases surface to volume ratio
- most abundant cell type in blood
Tasks of RBC’s
- carrying O2 from the lungs to the systemic tissue
- carrying CO2 from the tissues to the lungs
- assisting in the buffering of acids and bases
Shape of RBC’s
- allows them to squeeze through capillaries
- respond to osmotic changes
- provide evidence of disease
RBC’s in Hypertonic Solution
- cell shrink, but rigid cytoskeleton remains intact
- spiky surface
- cells are crenated
RBC’s in Hypotonic Solution
- cell swells and lose their characteristic biconcave disk shape
Hemoglobin
- RBC’s mainly consist of hemoglobin
- the O2 transport protein
- each are composed of 4 protein global chains
- each entered around a heme group
- 2 alpha and 2 beta chains