Cardiovascular Physiology 5 Blood and Hemostasis Flashcards
1
Q
what is the total blood volume in men and women
A
-men - 5L
-women- 4L
-about 7% body weight
2
Q
what are the components of blood
A
-cellular elements
-plasma
3
Q
what does the cellular elements include and how much of the blood does it make up
A
~45%
-blood cells- RBCs, WBCs, and platelets
4
Q
what is in the plasma and how much of the blood does it make up
A
~55%
-92% water
-7% plasma proteins
-1% dissolved substances such as organic molecules, ions, trace elements, vitamins, dissolved gases
5
Q
what are the functions of blood
A
- supplies nutrients and O2
- removes waste products and CO2
- carries regulatory factors (hormones)
- defends against infection (immune function)
- hemostasis (keeping blood in blood vessels)
6
Q
what makes plasma proteins and what are the types
A
liver
-albumins
-globulins
- fibrinogen
7
Q
what do albumins do
A
main determinant of Pi C
8
Q
what do globulins do
A
antibodies
9
Q
what do fibrinogens do
A
clotting proteins, zymogens
10
Q
what are the functions of plasma proteins
A
-maintain Pi C
-transport proteins for lipids (steroids)
- hormones
-extracellular enzymes
-immunity
-blood clotting
11
Q
what is serum
A
plasma - clotting proteins
12
Q
what do erythrocytes do
A
transport O2 and CO2
13
Q
what do leukocytes do
A
body defense
14
Q
what do thrombocytes (platelets) do
A
hemostasis
15
Q
what is hematocrit
A
percentage of total blood volume occupied by blood cells
16
Q
what is the normal hematocrit for men and women
A
45%
17
Q
what will hematocrit do to resistance, flow rate, and turbulent flow
A
-resistance: increase
-flow rate: decrease
-turbulent flow: decrease
18
Q
what is hematopoiesis
A
blood cell production
19
Q
where does hematopoiesis occur
A
red bone marrow- spongy bone
20
Q
what are all formed elements (myeloid and lymphoid) produced from
A
pluripotent hematopoietic stem cell
21
Q
what differentiates from a myeloid stem cell
A
erythrocyte
neutrophil
monocyte
eosinophil
basophil
megakaryocyte -> platelets
22
Q
what is the control factor for erythrocytes
A
erythropoietin
23
Q
what is the control for leukocytes
A
CSFs and ILs
24
Q
what is the control for thrombocytes
A
thrombopoietin
25
what do RBCs NOT contain
-no nucleus or organelles
-no DNA
-no centrioles
26
what are the enzymes in RBCs
-glycolytic enzymes for glycolysis
-carbonic anhydrase
27
how many hemoglobin molecules are there per RBC
2x10^8/ RBC
28
what filters RBCs
spleen and the liver
29
where is erythropoietin made
kidney
30
what factors cause hypoxia and thus stimulate erythropoietin
-low blood volume
-anemia
-low Hb
-poor blood flow
- pulmonary disease
-high altitude
31
what is the pathway of erythropoietin action
kidney -> makes erythropoietin -> hematopoietic stem cells ->proerythroblasts -> red blood cells -> tissue oxygenation
32
what are reticulocytes
young RBCs
33
what percentage of circulating RBCs do reticulocytes make up
1%
34
when do levels of reticulocytes increase
during periods of rapid RBC production
35
what does RBC production require
-iron
-folic acid
-vitamin B12
36
what is the normal Hb content of blood in men and women
men: 13-18 g/dL
women: 12-16 gram/dL
37
what is folic acid necessary for
DNA replication and cell division
38
what is vitmain B12 necessary for
DNA replication and cell division
39
what is a result of vitamin B12 deficiency
pernicious anemia
40
what happens when hemoglobin gets broken down
-globin is made into AA's
-heme is broken down into iron which gets recycled and stored as ferritin in the liver and bile pigments that are secreted into small intestine and excreted through the feces
41
what bile pigments are formed when RBCs are broken down
bilirubin and biliverdin
42
what is iron deficiency
Hb deficiency
43
what is hemochromatosis and effects
-too much iron
- damages liver, heart, pituitary gland, pancreas and joints
44
what do patients with chronic renal failure have to little of
erthyropoietin and require administration of synthesis forms to maintain normal RBC
45
what can happen to atheletes who misuse RBC synthetic form
can die from polycythemia bc increased RBC -> increases viscocity of blood -> increases resistance -> decreased blood flow and results in clotting, stroke, and heart failure
46
why do men have a higher hematocrit than women
testosterone enhances RBC production by increasing EPO
47
what is the definition of anemia
decrease in the O2 carrying capacity of blood by decrease in number of RBCs and or/ in Hb concentration
48
what is hemorrhagic anemia and cause
decrease in O2 carrying capacity due to bleeding
49
what is hemolytic anemia and cause
destruction of RBC due to malaria and/or sickle cell anemia
50
what is aplastic anemia and cause
bone marrow cannot perform erythropoiesis/hematopoiesis due to a bone marrow defect
51
what is renal anemia caused by
kidney disease
52
what is polycythemia defined by
hematocrit greater than 60%
53
what are the two types of polycythemia
-polycythemia vera
- secondary polycythemia
54
what is the cause of polycythemia vera
genetic condition that over produces RBCs
55
what is the cause of secondary polycythemia and effects
cause: hypoxia/high altitude
can cause heart failure
56
what are antigens on RBCs called
agglutinogens
57
most antigens on RBC are ____
relatively weak
58
what antigens on the RBC membrane is blood typing based on
A, B and Rh
59
what is the presence or absence of A and B antigens determined by genetically
incomplete dominance
60
what is the presence or absence of Rh antigens determined by genetically
mendelian genetics
61
when do antibodies to A/B antigens on RBCs appear
2-8 months after birth, NOT AFTER AN EXPOSURE
62
how are antibodies to A/B antigens introduced to immune system
through food and bacteria
63
when is maximum titer of antibodies to A/B antigens
10 years then declines with age
64
what happens when inappropriate A-B-O blood is transfused
agglutination
65
what does agglutination cause
obstruction of small blood vessels
66
what happens hour to days after agglutination and what is cause
hemolysis occurs due to extreme distortion of RBCs and action of phagocytic WBCs
67
what can the pathologic effects of agglutination do
can be extreme and fatal
68
what is blood transfusion made of
not whole blood, but packed RBCs
69
what is the reaction to worry about in blood transfusions
recipients plasma and donor's RBCs
70
what blood type is universal donor? universal recipient?
donor: O-
recipient: AB+
71
are there Rh antibodies in the blood?
no only if the person has been exposed
72
what happens if an Rh- person is exposed to Rh+ blood
may see mild agglutination response 2-4 weeks after exposure but first exposure is usually mild
73
what is erythroblastosis fetalis
Rh negative mother, Rh positive fetus
74
what happens in the first and second pregnancies in erythroblastosis fetalis
first: fetal red cells leak into maternal circulation during labor. mother develops anti-Rh antibodies. low risk to fetus because it occurs late in pregnancy
second: maternal IgG crosses placenta and destroys fetal RBCs
75
what is the treatment for erythroblastosis fetalis
administration of anti-RhD immunoglobulin (RhoGAM) after delivery
76
what are platelets derived from
megakaryocytes
77
what is the lifespan of platelets
10 days
78
what is the primary role of platelets
hemostasis- keeping blood in blood vessel
79
do platelets have nuclei and can they divide
no and no
80
what do platelets contain
- actin and myosin
-enzymes and organelles for aerobic CR
- enzymes for prostaglandin synthesis
- fibrin-stabilizing factor
-growth factors that stimulate endothelial cell, VSM, and fibroblasts to divide and grow
81
what are the 4 steps of hemostasis
1. formation of platelet plug to block hole in damaged vessel
2. vasoconstriction of damaged vessel to decrease blood flow and pressure
3. clot formation
4. clot dissolution
82
what are the steps leading to platelet plug and vasoconstriction
-platelets stick to damaged endothelial surface via Von Willebrand Factor
-platelets release contents of secretory vesicles
-stimulate production of thromboxane A2 from platelet plasma membrane
83
where do NSAIDs work
at the cyclooxygenase pathway
84
where do steroidal anti-inflammatory drugs like prednisone work
phospholipid -> arachidonic acid
85
what limits aggregation and activation of the platelet plug
NO and PGI2
86
what stimulates aggregation and activation of the platelet plug
TXA2
87
what is the definition of coagulation
blood converted into solid gel called clot or thrombus
88
where does clotting occur
around platelet plug
89
what is the function of a blood clot
to support and reinforce platelet plug
90
what is prothrombin activator and what does it do
it is a complex of Xa/Va and it activates prothrombin into thrombin
91
what does thrombin do
activates factor 13 which acts with fibrinogen to make stabilized fibrin
92
when is the intrinsic pathway activated
trauma to blood
-blood comes in contact with collagen from traumatized blood vessel wall
93
where are all the required factors for the intrinsic factors located
within the blood
94
which pathway is faster
extrinsic
95
when is the extrinsic pathway activated
trauma to vascular
trauma to surrounding extravascular tissue
96
what does the extrinsic pathway require
tissue factor (thromboplastin) produced by cells located outside of endothelial cells
97
what do instrinsic and extrinsic pathways both make
prothrombin activator
98
what does thrombus formation begin with
extrinsic pathway followed by intrinsic activation by thrombin
99
what ion is required for the clotting cascade
Ca2+
100
what is the required cofactor for enzyme IXa
factor 8
101
what are the 2 types of hemophilia, incidence rate and what factor do each not have
-hemophilia A- 90%- missing factor 8
-hemophilia B - 10%- missing factor 9
102
what does the liver need to produce zymogens
vitamin K
103
what is the role of the liver in making clotting factors
synthesizes bile salts -> bile salts in bile -> Gi tract absorbs vitamin K -> vitamin K in blood -> synthesizes clotting factors -> clotting factors in blood (zymogens)
104
why is it important to limit clot formation
prevent thrombus from spreading
105
what are the 3 things that limit clot formation
-tissue factor pathway inhibitor (secreted by endothelial cells)
- thrombomodulin causes activated protein C and inhibits factor 8a and 5a
-antithrombin III plasma protein inhibits thrombin
106
what are the steps in fibrinolysis
-the plasma protein plasminogen is trapped in a clot just like other plasma proteins
- injured tissues and endothelial cells slowly release tissue plasminogen factor (t-PA)
-t-PA converts plasminogen to plasmin a few days after clot is formed
-plasmin digests fibrin fibers, fibrinogen, prothrombin, and factors 5,8, and 12
107
what is a thrombus
a clot that forms and persists in an unbroken blood vessel
108
what can a thrombus lead to
can block the vessel, lead to ischemia, and tissue death downstream from the cloth
109
what is an embolus and what can it do
a free floating object in the blood stream, can wedge and occlude a vessel
110
what does pulmonary embolism do
impair oxygenation
111
what does a cerebral embolism do
cause strokes
112
what do low doses of aspirin do vs high doses
low: inhibit formation of thromboxane A2 by platelets but not prostacyclin by endothelium
high: inhibit formation of prostacyclin
113
what are the anticoagulants
-asprin
- heparin
- recombinant t-PA
-warfarin
-pradaxa
-plavix
114
what does heparin do
binds to antithrombin III and increases its activity by 100-1000x
115
what does recombinant t-PA do
dissolve intravascular clots if given immediately
116
what does warfarin do
blocks vitamin K
117
what does pradaxa do
blocks active site of thrombin
118
what does plavix do
blocks platelet activation
119
what is thrombocytopenia
a lack of platelets that causes spontaneous bleeding in small vessels even in normal movement
120
what causes thrombocytopenia
anything that affects bone marrow
121
what is the treatment for thrombocytopenia
platelet transfusion
122
how is liver disease a bleeding disorder
causes a lack of zymogens
123
what could cirrhosis and hepatitis require for treatment
tranfusions
124
what causes von willebrand disease and what happens
reduced levels of vWf
decreases platelet plug formation
125
what happens in vitamin K deficiencies
decreased synthesis of clotting factors
126
what are the 2 tests that assess coagulation and what do they each assess
-activation partial thromboplastin time (PTT/aPTT): assesses intrinsic pathway
-prothrombin time (PT): assesses extrinsic pathway
127
what is citrate used for in coagulation tests
prevents blood from clotting
128
what is a normal PTT
22-39 seconds
129
what is a normal PT
11-15 seconds
130
what is the formula for INR
PT patient/PT normal
131
what is a normal INR
less than 1.1
132
what does INR of 2-4 mean
-blood clots 2-4 times slower than normal
-effective therapeutic range
-OK for dental work
133
what does an INR of over 4 mean
risk of bleeding to great
-work with physician
