chapter 19-blood(cardiovascular system) Flashcards
cardiovascular system
blood, heart & blood vessels (anatomical division)
circulatory system
cardiovascular system & lymphatic system (clinical)
blood
-a fluid connective tissue
- 3 functions: distribution, regulation & protection
distribution (function of blood)
a. deliver O2 & nutrients to cells
b. remove metabolic waste
c. transport hormones to targets
what is the normal pH of blood?
7.4
blood is a type of CT, what’s its matrix?
plasma
what is the collective term for the blood cells
formed elements
the plasma proteins that are most abundant & most responsible for osmotic pressure of the blood are what?
albumins
what is the master stem cell for hematopoiesis?
hemocytoblast
what is the condition of an elevates hematocrit due specifically to RBCs?
polycythemia
rounded to the nearest whole number, erythrocytes are how many micrometers in diameter?
8
what specifically does oxygen bind to on a hemoglobin molecule?
iron ion(middle of the heme)
a person with a hematocrit of 34% would be described as having some of what?
anemia
during erythropoiesis, what’s the initial cell released into the blood from the bone marrow?
reticulocyte
what is the organ responsible for producing erythropoietin?
kidney
phagocytic cells release what into the blood from recycling of the heme pigment?
bilirubin (filtered by liver and ends up in bile making bile appear green)
someone with type B+ blood has what agglutinogens on the surface of their RBCs & automatically produces antibodies against which agglutinogen?
B & D, A
what is the leukocyte that functions to release histamine & heparin that contribute to the process of inflammation?
basophil
B cells, T cells & NK cells are types of what?
lymphocytes
what would describe the general condition of greater than normal numbers of WBCs in the blood?
leukocytosis
what is the largest cell in bone marrow that breaks off pieces of itself to produce platelets?
megakaryocyte
what is the hormone produced by the kidney that drives platelet production?
thrombopoietin
in the clotting cascade, factor X is activated to form what enzyme to facilitate the production of thrombin?
prothrombinase
what is released by endothelial cells to inhibit platelet aggregation to control the platelet plug size?
prostacyclin
a clot consists of platelets & other blood cells glues together in a web of what?
fibrin
what is critical to begin the activity of intrinsic pathway bc upon exposure to collagen or other charged surfaces it functions to activate factors VIII & IX?
factor XII
what is a free-floating blood clot that has the potential to block a vessel & lead to tissue death?
embolus
what is a disorder of lack of clotting due to deficiency in one or more of the clotting factors?
hemphilia
what mineral/ion that’s necessary for normal blood clotting?
calcium
regulation (function of blood)
a. maintain body temp. -> distribute heat from muscles
b. maintain pH
C. maintain fluid volume
protection (function of blood)
a. restrict loss at injury (clotting)
b. prevent infection (leukocyte)
characteristics of blood
-pH = 7.4
-temp. = 38°C / 100 °F
-total volume = 4-6L (9-11 pints)
how to estimate blood volume:
7% body weight in kg = blood in L (1kg = 2.2 Ib) -> weight Ib /2.2) x 0.07
blood matrix (composition of blood)
plasma ~55%
-water + soluble proteins
blood cells/formed elements (composition of blood)
-erythrocytes: ~45%, transport O2
-leukocytes: <1%, defense
-platelets: <1%, cell fragments for clotting
plasma
90% water + dissolved solutes (nutrients, gasses, hormones, wastes, ions, proteins)
plasma proteins
-8% of total plasma
-7.6g/100ml (5x more proteins than interstitial fluid)
-protein remain in plasma, not absorbed by cells for nutrients
albumins (plasma protein)
-60% of plasma proteins
-produced by the liver
function of albumins (plasma protein)
-act as pH buffer for blood
-contribute to osmotic pressure of blood (keep water in blood)
-transport fatty acids & hormones
globulins (plasma proteins)
-35% of plasma proteins
- 2 types: gamma globulins/ antibodies/ immunoglobulins & alpha and beta globulin/transport globulins
gamma globulins/ antibodies/ immunoglobulins (globulins -> plasma protein)
-produced by plasma cells in lymphatic system
-function to attack foreign substances
alpha & beta globulin/tranport globulins (globulins -> plasma protein)
-produced by the liver
-function to transport small or insoluble compounds to prevent filtration loss by kidney
clotting factors (plasma protein)
- 4% of plasma proteins
-produced by the liver
-11 total, fibrinogen most abundant
-all function to promote or form a clot (serum = plasma -fibrinogen)
other plasma proteins
-1% of plasma proteins
-from liver: metabolic enzymes & antibacterial proteins
-from endocrine organs: hormones
hematopoiesis
-blood cell production
-all formed elements arise from the same progenitor cell: hemocytoblast in the red bone marrow
hematopoiesis of basophils, eosinophils, neutrophils & platelets
exit the bone marrow to blood as mature cells
hematopoiesis of monocytes
must mature into macrophages by migrating from the blood to peripheral tissues
hematopoiesis of lymphoid stem cells
migrate from the bone marrow to lymphoid tissues to produce mature lymphocytes there
hematopoiesis of erythrocytes
enter the blood as reticulocytes which mature in the blood stream
erythrocytes (RBCs)
-99.9% of the formed elements of blood
-1/3 of total body cells
-4.2-6.3 million average
hematocrit
% of whole blood occupied by formed elements (mostly erythrocytes)
- male = 46%, female = 42%
polycythemia
excess erythrocytes but normal blood volume, usually due to bone marrow cancer
-increase in hematocrit = increase in viscosity = increase in heart strain & stroke
erythrocyte structure
-biconcave disc
-8μm
-large surface area for gas exchange
-can fold & stack to pass narrow vessels
mature erythrocyte structure
-lack all organelles
-no division, no repair
-low metabolic demands
-life span <120 days
-cell is 97% hemoglobin protein (red color)
-hemoglobin transport O2 & CO2
hemoglobin molecule (Hb)
- 2 alpha chains
-2 beta chains
-each chain has one heme group with iron in the center: iron binds to O2
-most O2 carried in blood bound to Hb (some in plasma)
-only 20% CO2 carried by Hb
oxyhemoglobin
O2 bound, bright red
deoxyhemoglobin
no O2, burgundy
carbaminohemglobin
CO2 bound to amino acids on alpha/beta chains, not on heme
-when plasma O2 is low, Hb releases O2 and binds CO2
-at lungs CO2 exchanged for O2 by diffusion
anemia
O2 starvation due to:
1. insufficient # RBCs
2. low Hb
3. abnormal Hb
thalassemia
inability to produce alpha or beta chains, slow RBC
production, cells fragile & short lived
sickle cell anemia
single amino acid mutation in beta chain, high O2 , cells normal low O2 , Hb misfolds, RBCs deform into crescent shape: fragile, blocks capillaries
erythropoiesis
red blood cell formation
-2 million/sec (1 oz new blood per day)
-occurs in reticular CT in red bone marrow, in spongy bone
erythropoiesis steps
- hemocytoblast differentiates into myeloid
stem cell - followed by many stages of differentiation, all involving increased protein synthesis
- cell fills with Hb, loses organelles
- 3-5 days reticulocytes are formed (Hb + some ribosomes), released into blood, 1-2% of total blood RBCs
- 2 days in circulation lose ribosomes (no more protein synthesis) = mature
erythrocyte
vitamin B12
-vitamin B12 necessary for erythropoiesis for stem cell division
-lack of B12 = pernicious anemia
erythropoietin (EPO)
-hormone, released by kidney during hypoxia (low O2)
-stimulated red blood production: increase in cell division rates & Hb synthesis = decrease in maturation
-kidney failure often= low RBCs due to lack of EPO
blood doping
injecting EPO or RBCs to enhance athletic performance: increase in O2 to tissues & increase in hematocrit/viscosity = clots, stroke, heart strain
erythrocyte recycling
-old/damaged RBCs removed by phagocytes in the spleen
-replaced by new, ~1% turnover per day
-phagocytosed cells are broken down
phagocytosis of proteins through erythrocyte recycling
protein -> amino acids, released for use
phagocytosis of heme through erythrocyte recycling
iron removed, bound to transferrin in blood for recycling back to bone marrow (new RBCs)
pigment in heme breakdown through erythrocyte recycling
pigment -> biliverdin (green) -> bilirubin(yellow-green), released into blood, filtered by liver, excreted in bile
pigment in heme breakdown in the gut through erythrocyte recycling
bilirubin -> urobilin (yellow) & stercobilins (brown) via bacteria urobilin absorbed, excreted in urine & stercobilins remain feces
hemolysis
RBC rupture in blood -> hemoglobinuria
hemoglobinuria
red/brown urine due to kidney filtering intact alpha & beta chains of hemoglobin
blood types
-all cell membranes have surface antigens
-RBCs have 50+, 3 important for transfusion agglutinogens: A,B,D
antigen
substance that triggers immune response
type A blood
surface antigen A (40%)
type B blood
surface antigen B (10%)
type AB blood
both A + B antigens (4%)
type O blood
neither A nor B antigen (46%)
Rh+ type blood
surface antigen D (85%)
Rh- type blood
no D antigen (15%)
blood type antibodies
-at birth, blood contains antibodies against A or B antigens that aren’t present
-the antibodies will cause agglutination (clumping) of antigen (agglutinogen)
-antibodies against D antigen only form upon exposure & are small enough to cross placenta
type A blood antibodies
antibodies against B antigen
type B blood antibodies
antibodies against A antigen
type AB blood antibodies
neither antibody
type O blood antibodies
antibodies against both A & B
hemolytic disease of the newborn/erythroblastosis fetalis
Rh- mom pregnant with Rh+ baby, gets exposed to D antigen during birth, makes anti-D antibodies, pregnant with second Rh+ baby, antibodies cross placenta, causes agglutination & lysis of fetal RBCs=anmeia & death
prevention of erythroblastosis fetalis
treat mother with RhoGAM during first birth to prevent antibody formation
leukocytes (WBCs)
-<1% total blood volume
-5 types
-all have nuclei & organelles, no hemoglobin
-6000-9000 leukocytes/μl blood
-use blood to travel to tissues, not permanent residents of blood
functions of leukocytes (WBCs)
-defend against pathogens
-remove toxins & wastes
-remove abnormal/damaged cells
characteristics of leukocytes (WBCs)
- amoeboid movement(crawl around blood)
- diapedesis(move out of blood)
a. margination
b. emigration - exhibit positive chemotaxis(move toward damage/infections)
- phagocytosis- engulfs pathogens & debris (3 of 5)
margination of diapedesis of leukocytes (WBCs)
adhere to blood vessels
emigration of diapedesis of leukocytes (WBCs)
pass between endothelial cells
neutrophils - granulocytes (polymorphonuclear-PMNs)
-non-specific defense
-phagocytic
-50-70% of WBCs
- 3-5 lobed nucleus
-12μm diameter
-granules contain enzymes & defenses
-mobile: first at injury
-life span <10h
neutrophils - granulocytes (polymorphonuclear-PMNs) functions
-respiratory burst
-degranulation
-prostaglandins
-leukotrienes
respiratory burst (function of neutrophils)
H2O2 & O2-, kill phagocytosed things
degranulation(function of neutrophils)
release defesnins, lyse bacteria
prostaglandins(function of neutrophils)
induce inflammation to stop spread of injury
leukotrienes (function of neutrophils)
attract phagocytes
eosinophils-granulocytes
-non-specific defense
-phagocytic
- 2-4% of WBCs
-bilobed nucleus
-12μm diameter
-granules contain toxins
-life span 9d
eosinophils functions-granulocytes
-phagocytosis of antibody-covered objects
-defense against parasites: exocytose toxins on large pathogens
-reduce inflammation: anti-inflammatory chemicals/enzymes
basophils-granulocytes(mast cells in tissues)
-non-specific defense
-not phagocytic
-<1% of WBCs
- U-shaped nucleus
-8-10μm diameter
-granules contain histamine & heparin
-life span 9d
histamine (contained in basophils)
dilate blood vessels
heparin (contained in basophils)
prevents clotting
basophil functions-granulocytes
inflammation allergic response via histamine
monocyte-agranulocytes (macrophages in tissues)
-non-specific defense
-phagocytic
-2% of WBCs
-15 μm + diameter
-kidney-shaped nucleus
-circulate 24h, exit into tissues
-life span several months
monocyte function-agranulocytes
-phagocytosis: virus & bacteria
-attract phagocytes
-attract fibroblasts for scar formation
-activate lymphocytes to mount immune response
lymphocyte-agranulocytes
-immune response (specific)
-20-30% of WBCs
-large round nucleus
- 5-17μm diameter
-migratory between blood & tissues
-most in lymphatic system
-life span days to lifetime
lymphocyte functions-agranulocytes
function depends on type, 3 types: B, T & NK cells
B cells (type of lymphocytes)
humoral immunity (secrete antibodies)
T cells (types of lymphocytes)
cell-mediated immunity (foreign cells)
NK cells (types of lymphocytes)
immune surveillance (destroy abnormal tissue)
granulocytes
named for visible secretory vesicles & lysosomes (stained)
agranulocytes
have lysosomes, but they aren’t visible
leukopoiesis
WBC production
-myeloid stem cells -> basophils, eosinophils, neutrophils, macrophages as directed by specific CSF produced by macrophages & T cells
lymphoid stem cells ->
lymphocytes production involves an immune response
leukopenia
too few WBCs
leukocytosis
excessive WBCs in normal blood volume >100,000/μl -> leukemia, cancerous stem cells, WBCs produced are immature & abnormal
infectious mononucleosis: epstein bar virus
infection causes production of excess agranulocytes that are abnormal, self-limiting
platelets (thrombocytes)
- flattened discs, 2-4μm, 1μm thick
-cell fragments, no nucleus
-constantly replaces, 9-12 d in circulation then phagocytosed by cells in spleen
-1/3 of total platelets held in reserve in spleen, mobilized for crisis
functions of platelets
-transport lotting chemical, release when activated
-form patch (platelet plug) over damaged vessels
-contract wound after clotting (contain actin & myosin)
thrombocytopoiesis
platelet production
thrombocytopoiesis process
-megakaryocyte in bone marrow break off membrane-enclosed cytoplasm to blood
-each megakaryocyte can produce ~4000 platelets
-induced by thrombopoietin from kidney & CSF from leukocytes
thrombocytopenia
too few platelets <80,000/μl, results in bleeding & petechia
thrombocytosis
too many platelets >1 million/μl, due to cancer or infection, clotting risk
hemostasis
-stop bleeding
- 3 phases: vascular spasms, platelets phase & coagulation
vascular spasms (1st phase of hemostasis)
-begins immediately after injury
-vasoconstriction of the vessels involved in the injury
vascular spasms (1st phase of hemostasis) triggers:
-injury to the vessel
-chemicals from damaged endothelial cells
-reflex triggered by pain receptors
endothelins (occurs concurrently with vascular spasms)
-released by endothelial cells
-a hormone
-stimulate vascular spasms & cell division to begin repair
von Willebrand factor(occurs concurrently with vascular spasms)
-released by endothelial cells
-promotes platelet sticking to endothelium
platelet phase (2nd phase of hemostasis)
-begins 15-sec post injury
- platelet adhesion, aggregation & plug size
-activated by thrombin
* sets up a positive feedback loop
platelet adhesion (platelet phase - 2nd phase of hemostasis)
platelets stick to enodthelium
platelet aggregation (platelet phase - 2nd phase of hemostasis)
platelets stick to each other forming a “platelet plug)
ADP (activated by thrombin in the platelet phase & platelets secrete it)
stimulates platelet aggregation & secretion
thromboxane (activated by thrombin in the platelet phase & platelets secrete it)
stimulates vascular spasm & chemo-attract platelets
serotonin (activated by thrombin in the platelet phase & platelets secrete it)
stimulates vascular spasm
clotting factors (5 of 11 proteins) (activated by thrombin in the platelet phase & platelets secrete it)
act in clotting cascade
platelet-derived growth factor (PDGF) (activated by thrombin in the platelet phase & platelets secrete it)
promote vessel repair
calcium ions (activated by thrombin in the platelet phase & platelets secrete it)
required for aggregation & clotting
coagulation (3rd phase of hemostasis)
- begins 30 sec post-injury
-multistep process, three important steps
coagulation (3rd phase of hemostasis) steps
- prothrombinase is formed from clotting factors
- prothrombinase converts prothrombin to thrombin
- thrombin converts fibrinogen into fibrin, which forms a mesh to plug the hole
blood clot
big mesh of fibrin: cells will later get trapped in it making it appear red
CSF (colony stimulating factor)
produced by macrophage/T cells
clotting cascade (events for coagulation)
-consists of calcium ions plus 11 proteins that each function as an enzyme to activate the next protein in a controlled series
-5 of the 11 clotting factors are released by activated platelets or endothelial cells
-the remaining 6 are always present in the blood as plasma proteins produced by liver
-2 methods to initiate clotting
extrinsic pathway (method of clotting cascade)
-fast, initiated by factors outside bloodstream
-only occurs in body
-factor III/tissue factor released by damaged endothelial cells or other tissue or activated platelets + factor VII + Ca2+
intrinsic pathway(method of clotting cascade)
-slow, initiated by factors present in blood
-can occur in a test tube
-factor XII activated by exposure to collagen (or other charged surfaces like class)
-factor XII causes factor VIII & factor IX to combine
common pathway (clotting cascade end result)
-come from either intrinsic & extrinsic pathways
-factor X is activated -> prothrombinase -> prothrombin -> thrombin which leads to fibrinogen -> fibrin
fibrin in the clotting cascade
forms a web that traps blood cells & platelets to seal off wound
-thrombin from the extrinsic & intrinsic pathways forms a strong clot
30-60 minutes post-injury of the clotting cascade
-clot retraction occurs to reduce wound size
-PDGF stimulates cell division to promote repair
fibrinolysis (after clotting cascade)
-clot is dissolved
-thrombin (common pathway) & tissue plasminogen activator (TPA from damaged tissue) activate plasminogen (in blood) to form pasta which digests fibrin
blood clotting normally prevented by:
- anticoagulation in blood that inhibits clotting factors (antithrombin III)
- heparin from basophils & endothelial cells activates antithrombin III
- protein C from liver stimulates plasmin to digest fibrin
- prostacyclin from endothelial cells prevents platelet aggregation
thrombosis (blood disorder)
clotting in undamaged vessels, slow or prevent flow (intrinsic pathway)
embolus (blood disorder)
free floating thrombosis, blocks small vessels -> tissue damage, heart attack, stroke
disseminated intravascular coagulation (blood disorder)
widespread clotting followed by systemic bleeding, rare: complications of pregnancy, septicemia or mismatched transfusion
-body-wide clotting
hemophilia (blood disorder)
inadequate production of clotting factors
-type A -> factor VIII (X chromosomes linked)
-type B -> factor IX
-type C -> factor XI
dietary blood disorders
-calcium required for clotting cascade
-VitK required for liver to synthesize clotting factors
-iron required for hemoglobin production
-VitB12 required for RBC stem cell division
organ health blood disorders
-impaired liver = decreased clotting (decreased clotting factors)
-impaired kidney = decreased RBC (decreased EPO) decreased platelets (decreased thrombopoietin)
