Exam 3 Hematopoietic CT: Blood Flashcards
Normal blood volume
5L or 7% body weight
Fluid portion of blood
Plasma and Serum
Plasma
= serum + proteins
Protein carriers, antibodies, coagulation proteins, complement proteins, osmotic proteins
Serum
=mostly water and electrolytes
devoid of clotting proteins and cells
plasma-clotting factors
Cellular portion of blood
RBCs
WBCs
Platelets
Blood in a test tube
RBCs settle to the bottom
Thin layer of WBCs
Plasma/serum at the top (largest portion)
Characteristics of Plasma
Fluid portion of blood; contains several different soluble molecules:
- plasma proteins = 70% of solutes
- Inorganic salts (NaCl) = 9% of solutes
- Amino acids, vitamins, hormones, lipoproteins, carbohydrates = 21% of solutes
Plasma transports
- nutrients (O2) to tissues and metabolic waste from tissues to kidneys
- hormones for conveying cellular signals from distant sites
- CO2 to the lungs for expiration
Plasma helps maintain the
acid-base balance of bodily fluids
Blood participates in regulation of
body temperature through conduction of heat from cutaneous vessels
Plasma proteins
Albumin, globulins, fibrinogen, lipoproteins, complement proteins
albumin
creates osmotic force to “draw” water into the blood
Globulins
(alpha, beta, and gamma globulins)
-enzymes (alpha and beta)
antibodies for the immune system (gamma)
Fibrinogen (and clotting factor proteins)
provide coagulation of blood
Lipoproteins
transport mechanism for lipids/fats
Complement proteins
assist in immune system function
Most plasma proteins are synthesized by the
liver
Blood cells
erythrocyte leukocytes agranulocytes granulocytes platelets stem cells
erythrocyte
red blood cell (RBC) - O2/CO2 transport
leukocytes
white blood cells (WBC) - immune system (agranulocytes, granulocytes)
agranulocytes
lymphocytes (T and B cells), monocytes and macrophages
granulocytes
neutrophils, eosionophils, basophils, mast cells
platelets
blood clotting
stem cells (bone marrow)
pluripotent cells capable of self-renewal to replace all blood cell types
Normal concentration of WBCs in Blood
3,900-10,800 cells/uL (mm^3)
Normal concentration of platelets in blood
150,000-400,000 cells/uL (mm^3)
RBCs normal concentration in blood
Female - 3.6-4.8 x 10^6
Male - 4.2-5.2 x10^6
*men have more RBCs than women
Stem cell differentiation
- bone marrow consists of a pool of undifferentiated (pluripotent) stem cells
- upon molecular signaling, stem cells become irreversibly differentiated cell types (ie: RBCs, WBCs, platelets - myeloid, lymphoid cells)
- Stem cells that are recruited for differentiation are replaced by proliferation of other undifferentiated cells from the pool - process maintains a constant number of stem cells
Erythrocytes characteristics
filled with hemoglobin for transport of O2/CO2
- mature RBCs do not contain mitochondria, ribosomes, or nuclei
- under normal conditions, RBCs never leave the circulatory system
RBCs are flexible, which permits adaptation to irregular shapes and small diameter of capillaries
RBC Life span =
120 days
Old RBCs are removed by the
spleen
Hemoglobin Molecule characteristics
Composed of 4 protein molecules (2 alpha chains, 2 beta chains)
Each chain binds one O2 or CO2 molecule
Erythrocytes (Hb): Clinical Correlate - Sickle Cell disease
Inherited disorder of RBCs
Single AA mutation of the gene that produces hemoglobin
When deoxygenated, dysfunctional hemoglobin polymerizes abnormally,
Sickle-shaped RNC increases blood viscosity (can reduce or totally block blood flow through capillaries)
Normal range of Hemoglobin (gm/dL) Males
14-18
Normal range of hemoglobin (gm/dL) females
12-16
Normal range hematocrit (%) male
42-52%
Normal range hematocrit (%) female
36-48%
Reduced exercise capacity occurs at what hemoglobin range?
8-10
exercise cautiously
Reduced exercise capacity at hematocrit of
< 30%
Light exercise recommended at hemoglobin
7-8 gm/dL light exercise if NOT SYMPTOMATIC
Light exercise recommended at hematocrit
24-30%
Hemoglobin value indicating not to perform activity
< 7 g/dL
Don’t perform activity at hematocrit
< 24%
Life span of neutrophils
6-7 hours in blood, and 1-4 days in connective tissue
Functions of neutrophils
- 1st line of defense against foreign agents
- phagocytize bacteria and remove cell debris (die in area and release cell contents = pus)
- increased number in the blood in the blood indicates a bacterial infection
Phagocytosis
- pseudopodia surround microorganism (bacteria)
- internalization into vacuoles called phagosomes
- intracellular granules fuse with phagosomes
- lysosomal enzymes (granules) destroy microorganism
- free radicals are formed by PMN and are released to assist in killing other bacteria
Steps of phagocytosis
- Microbe is detected
- Psuedopodia surround bacterium
- Bacterium is ingested forming a phagosome
- Fusion of lysosome and phagosome
- Digestion of the ingested material
- Release of digestion products from the cell - includes free radicals that are toxic to bacteria)
Eosinophils characteristics
Filled with large granules that contain inflammatory mediator molecules
-and increased number indicates an allergic reaction or parasitic infection
Functions of eosinophils
Phagocytosis of parasites and viruses by recognizing antigen/antibody complexes on the foreign agents
-involved in allergic reaction (release molecules that increase vascular permeability and vasodilation)
Basophils (mast cells)
release granules (histamine, heparin) associated with bodily reactions to allergens
Granules released by basophils stimulate
Bronchoconstriction, vasodilation, increased vascular permeability
Bronchoconstriction
constricts airways
Vasodilation
increase blood flow to local area
Increased vascular permeability
creates local edema
Types of lymphocytes
B lymphocytes (B-Cells) T lymphocytes (T-cells)
Functions of Lymphocytes
immune system
-detect and destroy
invading microorganisms, foreign macromolecules, cancer cells
B lymphocyte
provide antibody-mediated immunity (humoral immunity)
Activated B-cells become
Plasma cells
Plasma cells
synthesize and secrete antibodies (IgM, IgG, IgE)
Antibodies against microorganisms
IgM, IgG
antibodies against allergens
IgE (bound to basophils/mast cells)
Antibodies recognize
specific antigens on the surface of micro-organisms, cancer cells, and foreign molecule
T-Lymphocyte
Provide cell mediated immunity
T-cells recognize
Specific antigens on mico-organism, cancer cells, foreign cells, and damaged cells
T-Cells bind to
pathogenic cells, viruses, cancer cells, and destroy them
T-cells are responsible for transplant graft
rejection
Killer T-Cells (Tk) function
Directly kill antigen or non-self cell by inserting a protein channel
Suppressor T-Cells (T8 or Ts)
Reduce activity of T or B cells, i.e. limit immune response
Memory T-Cells (Tm)
Activated during initial exposure, can activate quickly with re-exposure
Lymphokine-producing T Cell
Produce lymphokines that further activate T, B cells, and macrophages
T-Helper cells (T4 or Th)
Activate Tk and B-cells
Monocytes
immature macrophages that exist within the circulation
When monocytes leave the circulation
leave the circulation and differentiate into macrophages
Monocyte functions (as macrophages)
- phagocytize pathogens, dead neutrophils, and cellular debris
- Activate lymphocytes by “presenting” antigens
- Release cytokines and growth factors that direct inflammation and tissue healing
Types of macrophages
2
Fixed and wandering
Fixed macrophages
Located in peripheral tissues/organs outside
Wandering macrophages
circulate between blood and lymph fluid looking for foreign microbes
Both types of macrophages serve to
recognize and phagocytize pathogens and present antigens to lymphocytes
Platelets
Non-nucleated, disk-like cell fragments formed from giant megakaryocytes
Functions of platelets
blood clotting
- repair gaps in walls of blood vessels
- cell membrane of platelets contains glycoproteins which aid in platelet adhesion to vessel wall and to each other
150,000-400,00 /uL platelet implications
normal
50,000-150,000 /uL platelet implications
thrombocytopenia - moderate resistance exercise
20,000-50,000 /uL platelet implications
light resistive exercise, walk, stationary bike
<20,000 /uL platelet implications
no activity except ADLs and Ambulation
<5,000 /uL platelet implications
No activity/bed rest
Blood clot formation
- Damage to vessels stimulates platelet activity
(platelets become “sticky when they come in contact with non-endothelial cells/molecules; platelets stick to walls of damaged vessel and to each other - make a platelet plug) - Clotting proteins (fibrinogen) are stimulated by contact with damaged endothelium and non-endothelial tissue (enzymatic cascade results in conversion of inactive fibrinogen into active fibrin; fibrin “fibers” adhere to platelet plug and increase blood clot)
Clotting Cascade: intrinsic pathway
stimulated by contact with extra-vascular tissue
Clotting cascade: extrinsic pathway
stimulated by contact with damaged endothelial cells
End result of clotting cascade
is formation of fibrin molecules that provide fiber network for clot - helps trap additional platelets, RBCs, and WBCs
Blood clotting clinical application: Hemophilia
Sex-linked inherited disorders of blood coagulation
deficient or absent blood clotting factors
blood clotting is time prolonged; allows for pathological bleeding
patients can bleed severely after mild injuries; can result in fatal hemorrhage
Blood clot removal
Plasminogen - blood protein that is trapped within a blood clot
Tissue plasminogen activator (tPA or PLAT) - protein that is found on endothelial cells, enzymatically converts plasminogen into plasmin
Plasmin - dissolves the clot to restore flow through the previously damaged veseel
Blood clotting: clinical application, tPA (tissue plasminogen activator)
used on patients with an acute occlusion of coronary or cerebral arteries (CVA) due to embolic thrombus; dissolves clots and reduces time of ischemia; reduced ischemia reduces the overall cell/tissue damage that occurs; results in fewer deficits for patients
Thrombi can form pathologically on..
roughened endothelial surface of a vessel due to: arteriosclerosis, atherosclerosis, infection, trauma
thrombi reduce
blood flow through a vessel
reduced blood flow through a vessel increases
coagulability of blood, promotes increased “growth” of clot
Deep vein thrombosis (DVT)
pathological thrombus formation within lower extremity veins
can break away from vessel wall (embolize)
Embolized DVTs
follow circulation to pulmonary vessels (pulmonary embolus) and create lack of blood flow to lungs
