Chapter 19 BLOOD Flashcards
Define Blood
Fluid connective tissue
transport system
5 Functions of blood
Transport, regulate, prevents, protects, stabalizes
- Transport of gases, nutrients, waste & hormones
- Regulation; ph, fluid, electrolyte balace
- Prevents fluid loss at injury site=clotting
- Protection=WBC
- Stabilizes body temp=circulation, body absorbs heat & distributes it to other parts of the body
Whole blood, Plasma
fluid consisting of water, dissolved plasma protein
Whole blood, Formed elements
all cells and cell fragments
Three types of formed elements
- RBCs / erythocytes (Red cells transport O2)
- WBCs or leukocytes=part of immune system
- Platelets=cell fragments involved in clotting
amount of blood
4 - 6 liters incl. plasma (46-63%) and blood cells (37-54%) of total blood volume
Temperature of blood
100.4 high to maintain heat distribution
Bright red blood
arterial blood , due to O2 venous blood
Darker red blood
darker, dull due to O2 deficit
PH
7.35 - 7.45 (slightly alkaline)
Viscosity/thickness or resistance to flow
5X thicker than water because of blood cells and plasma viscosity which maintains normal blood pressure
Plasma definition
liquid part of the blood, 92% water
water solvent enables plasma to transport substances, 5 examples:
- nutrients circulated to tissue and organs
- waste circulated to kidneys
- hormones carried to target organs
- antibodies circulated to infected areas
- carbon dioxide carried to lungs in the form of bicarbonate
Plasma Proteins
synthesized by liver, contribute to the transfer of molecules to and from blood; cannot cross capillary walls because of large size
Albumin
most abundant plasma protein; synthesized in liver, provides colloidosmotic pressure which attracts tissue fluid into blood plasma; helps maintain normal blood volume and pressure
Globulins
Transport proteins
hormone-binding binds and transports hormone like the thyroid binding globulin
metalloproteins transport metals like transferrin
apoliopoproteins carry triglycerides and other lipids in the blood like lipoproteins
steroid binding proteins-transport steroid hormones like, testosterone bending globulin
fibrinogen
clotting factor, inactive until needed by ruptured vessels, then converted to fibrin which forms the basic clot framework
serum
the fluid resulting from removal of clotting factors
Blood Cells
produced in hemopoietic tissues; red bone marrow and lymphatic tissue
Red blood cells (fig. 19-2)
RBCs/erythrocytes=smarty shape, biconcave center
Hemopoiesis
production of formed elements from myeloid and lymphoid stem cells
Shape gives RBCs
a large surface area for quick absorption and release of O2 molecules (3800 sq. M)
flexibility to get through narrow capillaries
rouleau
shape of BCs allows cells to stack, smoothing flow through narrow blood vessels
no mitochondria in RBCs so where does it get its energy?
anaerobic glycolysis
Hematcrit
measures blood cells by centrifuge. formed elements and plasma separate and percentage can be detrmined
hemacrit for males and females?
46- males
42-females
Hemoglobin
protein in RBC which carries O2
Hemoglobin count from males and females?
Male-14 - 18 g/dL
Female- 12 - 16 g/dL
Each HB molecule has
2 alpha and beta chains of polypeptide within a quaternary protein structure, ea. chain contains a single heme molecule
Each heme unit holds
one Fe and ea. Fe molecule holds one O2 molecule
how many hemoglobin molecules per one RBC
280 million (ea. of which can bond to 4 oxygen molecules)
oxyhemoglobin
RBC carrying oxygen (bright red)
deoxyhemoglobin
RBCs travel through tissues and give up there oxygen (dark red)
Fetal hemoglobin
strong form, found in embryo, takes O2 from moms
function of hemoglobin
carries oxygen
carbaminohemoglobin
when plasma oxygen levels are low, hemoglobin releases oxygen and binds to carbon dioxide, takes it to lungs
anemia
if hematocrit levels are low or HB content is reduced; body suffers from oxygen deprivation
RBC formation / turn over
120 day lifespan, travels 700 miles, 1 % of RBCs wear out per day and about 3 million enter the blood stream per sec.
Hemoglobin conversion and recycling process
see fig. 19-5
production and maturation of blood cells
embryonic RBCs are formed in 3ed wk of development, yolk sac is the 1st site of blood cell formation; then the liver and spleen
erythropoiesis
RBC formation occurs in myeloid tissue (red bone marrow), stem cells mature to become RBCs
Red bone marrow
found in flat and irregular bones of adults
yellow bone marrow
fatty tissue that can convert to red bone marrow during severe trauma / blood loss
- hemocytoblasts
blood producing precursor cells produced in red bone marrow
hemocytoblasts continuously produce 2 kinds of blood cells
myeloid-become RBC’s, some WBCs
lymphhoid stem cells-become lymphocytes
- proerythroblasts
fist stage of an RBC; day 1
- basophilic erythroblast
2ed day of maturation
- polychromatophilic erythroblast
day 3 of maturation
- normoblast
day 4 of maturation; last developmental stage where RBC still has nucleus…end of stage nucleus disintegrates
- reticulocyte
days 5-7 of maturation; contains 80 % of hemoglobin of a mature RBC; enters circulation after day 7 and takes another 24 hrs to mature fully
7.erythocytes
blank
what is necessary for the synthesis of hemoglobin?
protein, iron, copper
what extrinsic factor is necessary for DNA synthesis in the bloods cells of red bone marrow?
B12
Intrinsic factor
gastric cells produce this to bind to dietary B12 so that it won’t be digested, its absorbed into small intestines
**Erythropoietin
Hormone, stimulates erythropoiesis directly or indirectly by stimulation thyroxine, androgens and growth hormone
Erythropoietin, stimulated by low ___ levels during anemia, blood flow to ____ declines or oxygen content to ____ declines
oxygen
kidney
lungs
Erythropoietin travels to red bone marrow and stimulates
stem cells
Erythropoietin increases rate of cell division in
eurethrablasts
Erythropoitin speeds up maturation of RBCs by accelerating
hemoglobin synthesis
Blood doping
athletes elevate hematocrits by reinfusing RBCs that were removed and stored at an earlier date; improves O2 delivery to muscles but can be hard on the heart because of increased viscosity
typing and crossmatching
it is important to ensure that donated blood will not be reacted on
Cross-reaction
when an antibody meets its specific surface antigen, the RBCs agglutinates and may hemolyse
White blood cells
leukocytes larger than RBCs and have a nuclei when mature; function is immunity
WBC count
5000 to 10,000 per mm3 (some are in tissue)
WBCs have
nucleus and organells
WBC lack
hemoglobin
WBC functions, 3
- defend against pathogens
- remove toxins/waste
- attract abnormal cells
WBC circulation and movement
most found in connective tissue and lymph. system organs; small number in blood (5000 - 10000)
4 characteristics of circulating WBCs
- can migrate through diapedisis or emigration
- have ameboid movement so it can move through endothelial linings
- attracted to positive chemotaxis, guiding WBCs to damaged tissue or pathogens
- some are phagocytic; neutrophils, eosinophils and nomcytes
Granular Leukocytes
produced in red bone marrow, have colored granules when stained, have lobed nuclei, neutrophils, eosinophils and basophils
Neutrophils
prefer bacteria and fungi
50 - 70 % of circulating WBCs
cytoplasm has lysosomal enzymes and bactericides (hydrogen peroxide)
Neutrophils are very…
active, 1st to attack bacteria
engolf and digest pathogens
Defensens
attack pathogen membranes
Neutrophils release…
prostaglandins that increase capillary permeability contributing to inflammation which restricts the spread of injury or infection
leukotrines
hormones that attract other phagocytes and help coordinate the immune response
Puss is
dead neutrophils, cellular debris and waste
Eosiniphils (acidophils)
2-4 % of WBCs
attacks parasitic worms that are too large to be phagocytized
Eosiniphils excrete the toxic compounds
nitric oxide and cytotoxic enzymes through exocytosis
Eosiniphils are sensitive to
allergens so they increase in number during allergic reactions
Eosiniphils control inflammation with enzymes that
counteract effects of neutrophils and mast cells
Basophils
ratest WBC, smaller than neutrophils
Basophils bind to
antibody that causes granules to release histamine, dilating blood vessels
Basophils release
heporine to prevent clotting and attract other eosinophils and basophils to the area
agranular leukocytes
produced in spleen, lymph nodes and thymus, red bone marrow, lymphocytes and nomocytes
monocytes
largest leukocyte, twice the size of an RBC
leave blood stream and enter peripheral tissue and become macrophages with big appetite
Monocytes phagocytize:
viruses, bacterial parasites and dead tissue
Monocytes secrete
substances that attract immune system cells and fibroblasts that lay down scar tissue to injury
Lymphocytes
Larger than RBCs, migrate in and out of blood, found in connective tissues and lymphoid organs, they are part of the body’s defense system
Three classes of lymphocytes
- T-cell-mediated immunity; attack foreign cells
- B-humoral immunity; turn into PLASMA CELLS and synthesize antibodies that travel throughout the blood to destroy their target
Differential WBC count
percent of ea. kind of leukocyte
Leukocytosis
high WBC count = infection
Leukopenia
Low WBC count
Lymphopoiesis
formation of lymphocytes
Platelets
fragments of cells that play a major role in clotting
thrombocytopenia
abnormal low platelet count
thrrombocytosis
high platelet count, signifies cancer of infection
3 functions of platelets
- release clotting chemicals
- patch damaged vessel walls temporarily
- reduces size of a break in vessel wall
Platelet production called
thrombopoiesis
4 Thrombopoiesis facts
- stem cells turn into megakaryocytes which break up into sm. pieces that enter circulation
- platelets survive 9-12 days
- removed from circulation by spleen
- 2/3 stored for emergencies
Hemostasis
stopping of bleeding
Hemostasis, 3 phases (happen all at once)
vascular phase; causes vascular spasm, decreasing the diameter of the vessels; lasts 30 min
platelet phase; beginning=attachment of platelets to endothelial surface (15 sec of injury occurrence)
*Coagulation phase (see coagulation card, know for test!)
Coagulation phase
dependent on clotting factors (procoagulants) in pathway; incl calcium and 11 proteins; causes a cascade reaction of enzymes and proenzymes that ends in the conversion of circulation fibrinogen into insoluble fibrin (fibrin is the end result)
The Extrinsic Pathway (3)
outside blood stream, in vessel wall
- damaged cells release tissue factor (TF)
- TF + other compounds and calcium= enzyme complex
- activates factor X
Intrinsic pathway (in blood stream 4 steps)
- begins with circulating proenzymes within bloodstream
- activation of enzymes by collagen
- platelets release factors
- series of reaction activates factor X
** Common Pathway, define and 2 steps
begins when enzymes from eithr the ex or intrinsic pathway activate factor X
- the enzyme prothrombinase is formed; converts prothrombin to thrombin
- thrombin converts fibrinegen to fibrin
blood clotting is a
positive feedback mechanism to accelerate the clotting process and reduce blood loss quickly
Blood clotting is restricted by (3)
- anticoagulants such as antithromin-III inhibit thrombin
- Heparin released by basophils and mast cells activates antithrombin III
- aspiri prevents platelet aggregation and clot formation but prolongs bleeding
clot retraction
pulls torn edges of vessel closer together reducing residual bleeding and stabilizing injury site; reduces size of damage making it easier for fibroblasts, smooth muscle cells and endothelial cells to complete repair
Fibrinolysis
slows process of dissolving clot; plasmin digests fibrin strands
