Ch. 19 Blood Flashcards
Functions of blood
- transport tissue (gases, nutrients, waste products, processed molecules, regulatory molecules)
- regulates pH and osmosis
- maintenance of body temp
- protection
- clot formation
Plasma
- liquid part of blood
- composed of water, proteins,ions, nutrients, waste products, gases, and regulatory substances
Water in plasma
- acts as a solvent and suspending medium for blood components
- 91%
Proteins in plasma
-albumins, globulins (alpha, beta, gamma), fibrinogen
Albumins
- makes up 58% of plasma proteins
- partly responsible for blood viscosity and osmotic pressure
- acts as a buffer
- transports fatty acids, bilirubin and thyroid hormones
Globulins
- 38% of plasma proteins
- transport proteins
Alpha globulin
- protects tissues from inflammation damage
- transports thyroid hormones, lipids, and hemoglobins
- converts ferrous iron to ferric iron
Beta globulin
- transports iron and lipids
- involved with immunity
- prevents blood loss (coagulation protein)
Gamma globilin
-involved with immunity
Fibrinogen
- 4% of plasma proteins
- formation of blood clots
Ions
-involved in osmosis, membrane potentials and acid base balance
Nutrients
- source of energy
- basic building block of more complex molecules
Waste products
- Urea, uric acid, creatinine, NH3: breakdown products of protein metabolism; excreted by the kidneys
- bilirubin: breakdown product of red blood cells; excreted as part of bile from liver to small intest.
- lactic acid: end product of anaerobic respiration; converted to glucose by liver
Gases
- oxygen: necessary for aerobic resp.
- carbon dioxide: waste product of aerobic resp; as bicarbonate (helps buffer blood)
- nitrogen: inert
Regulatory substances
- enzymes catalyze chemical reactions
- hormones stimulate or inhibit body functions
Serum
-whats left of plasma when all the solids are out (without the clotting factors)
Formed elements of blood
- red blood cells (erythrocytes) (95%)
- white blood cells (leukocytes) and platelets (thrombocytes) (5%)
Red blood cells
- transports oxygen and carbon dioxide
- no nucleus
- biconcave disc
White blood cells
- 5 different types each with specific funtction
- spherical with nucleus
WBC-neutrophil
- granulocytes
- phagocytizes microorganisms and other substances
WBC-eosinophil
- granulocytes
- release chemicals that reduce inflammation
- attack certain worm parasites
WBC-basophil
- granulocytes
- realeases histimine, which promotes inflammation
WBC-lymphocyte
- agranulocyte
- produces antibodies (b-cells and t-cells)
- contributes to allergic reactions
WBC-monocyte
- agranulocyte
- phagocytic cell in blood
- leaves the blood and becomes a macrophage (which phagocytizes bacteria, dead cells, cell fragments)
Platelet
- cell fragment
- forms platelet plugs
Hematopoiesis
-start with stem cells (hemocytoblast) that is in marrow
HTP- proerythoblast
-where red blood cells develop
HTP-myeloblasts
-where basophils, eosinophils, and neutrophils develop
HTP-lymphoblast
-where lymphocytes develop
HTP-monoblast
-where momcytes develop
HTP-megakaryoblast
-where platelets develop
Red blood cells
- lose nuclei and nearly all cellular organelles during maturation
- main component is hemoglobin (accounts for red color)
Primary function of RBC
- transport oxygen from lungs to the various body tissues
- transport CO2 from tissues to the lungs
- 98.5% of oxygen in blood is transported with hemoglobin
Primary function of RBC 2
-CO2 is transported in 3 ways: 7% is dissolved in plasma, 23% is combined with hemoglobin, 70% is in the form of bicarbonate ions
Hemoglobin
-consists of 4 polypeptide chains and 4 heme groups (contains one iron atom)
Forms of hemoglobin
- embryonic:produced during development
- fetal: in place by third month of development
- adult: 60-90% is in place at birth
Difference in hemoglobin
- different affinities for oxygen
- embryonic and fetal have higher affinity because of the switching of the globin groups
Oxyhemoglobin
- oxygenated form of hemoglobin
- bright red
Deoxyhemoglobin
- hemoglobin containing no oxygen
- dark red
Carbaminohemoglobin
-hemoglobin that carries CO2
Erythropoiesis
- the proces by which new red blood cells are produced
- takes about 4 days
EPO (erythropoietin)
- hormone produces mostly by the kidneys
- stimulates red bone marrow to produce more red blood cells
Hemostasis
-the stoppage of bleeding
Vascular spasm
-immediate but temporary constriction of a blood vessel (capillary)
Platelet plug
-an accumulation of platelets that can seal small breaks in blood vessels
Platelet plug formation
-platelet adhesion, release and activation, and aggregation
Platelet adhesion
- when platelets binds to collagen
- mediated through von Willebrand factor
- activates platelets
Platelet release reaction
- ADP, thromboxanes, and other chemicals are extruded from the platelets by exocytosis
- ADP and thromboxane bind to their receptors and activate them
- activated platelets release more chemicals, producing a cascade of chemical release
Platelet aggregation
-fibrinogen forms a bridge between fibrinogen receptors of different platelets, resulting in a platelet plug
Coagulation
-blood clotting formation for a blood vessel that is severely damaged
Clotting factors
- found within plasma
- normally inactive until needed
Extrinsic Pathway
- starts in the tissues outside of the blood
- ultimately activate factor X
Intrinsic Pathway
- starts within the blood
- ultimately activate factor X
Anticoagulants
-prevents unwanted clotting by inhibiting one of the factors
Clot retraction
- after formation of clot, it begins to condense into a denser, compact structure
- platelets contain actin and myosin that contract the extensions of platelets
Clot dissolution
-after vessel is repaired by fibroblasts, the clot dissolves within a few days by the activity of plasmin
Blood counts
RBC
-number of red blood cells per microliter of blood
Blood counts
Hemoglobin
-the amount of hemoglobin in a given volume of blood
Blood counts
Hematocrit
-the percentage of the total blood volume that is composed of red blood cells
Blood counts
WBC
-measures the total number of white blood cells in the blood
Blood counts
differential WBC
-determines the percentage of each of the five kinds of white blood cells
