Blood Flashcards
1
Q
What is blood?
A
a highly dynamic tissue, part of the cardiovascular system
2
Q
What are all the blood functions? (7)
A
Transport Nutrients
Transport Respiratory Gasses
Transport Excretion of Wastes
Hormone Transport
Temperature Regulation
Acid-Base Balance
Protection
3
Q
What is the blood normal pH range?
A
7.30-7.45
4
Q
What are the 3 components/layers of blood?
A
Plasma 55%
Buffy layer (WBCs, Platelets)
RBCs
5
Q
What fluids does the blood contain?
A
Extracellular Fluid ECF (plasma)
Intracellular Fluid ICF (fluid inside the Blood Cells)
6
Q
What is the normal blood volume?
A
~5 L or ~7% of body mass.
7
Q
What is the difference between normovolemia, hypovolemia, and hypervolemia?
A
Normal blood volume is normovolemia,
lower blood volume is hypovolemia, and
higher blood volume is hypervolemia.
8
Q
What is the Hematocrit (Ht)?
A
The percentage of Blood Volume occupied by Red
Blood Cells.
9
Q
What is the blood volume occupied by RBCs if the Hematocrit is 45%?
A
~2.25 L.
10
Q
What is the volume of blood occupied by plasma if
the Hematocrit is 45%?
A
~2.75 L.
11
Q
What is the composition of plasma? (4)
A
- > 90% water
- Ions:
main: Na+. Cl-
K+, (Ca++, Mg++), HCO3-, (PO4-) - Nutrients, Respiratory Gasses, Wastes (Glucose, Amino Acids, Lipids, O2, CO2, Urea, Lactic Acid)
- Proteins (colloids)
12
Q
What are the 3 plasma protein seen in class?
A
Albumins
Globulins
Fibrinogen
13
Q
How are plasma proteins separated? (4)
A
-Differential Precipitation by Salts
-Sedimentation in Ultracentrifuge
-Electrophoretic Mobility
-Immunological Characte
14
Q
What is electrophoresis?
A
a fractionation method based on
the movement of charged particles along a voltage
gradient.
15
Q
What is the rate of migration in electrophoresis influenced by? (3)
A
the number of charges
the distribution of charges
the molecular weight
16
Q
Why is there no fibrinogen peak in serum electrophoretic pattern?
A
Serum is plasma with fibrinogen, the clotting factor,
removed.
17
Q
What is the origin of plasma proteins?
A
Except for gamma globulin, plasma proteins are
synthesized in the liver.
(Gamma globulin by Lymphoid tissue)
18
Q
What happens to plasma protein levels when the
liver is diseased?
A
They decrease.
19
Q
Why is the peak of albumin much reduced in the Electrophoretic Pattern in
Renal Disease ?
A
Renal diseases causes often too much permeability in the level of the renal tubules and the smallest plasma protein is able to flow out into the urine.
20
Q
Why is the peak of Gamma globulin much bigger in the Electrophoretic Pattern in
Bacterial Infection?
A
Because we are producing lots of antibodies
21
Q
Which plasma protein am I?
The smallest
A
albumin
22
Q
Which plasma protein am I?
I come in a variety of shapes
A
globulin
23
Q
Which plasma protein am I?
I am fibrous: long and thin.
A
Fibrinogen
24
Q
Which plasma protein am I?
My weight is a big range from 90-800 kDa.
A
globuin
25
Which plasma protein am I? Present highest concentration
albumin
26
Which plasma protein am I?
Present lowest concentration
fribinogen
27
What is the function of plasma protein?
Play a major role in determining the distribution of fluid between the plasma and the ISF compartments by controlling transcapillary dynamics
28
The cell membrane is relatively impermeable to ____________.
The capillary wall is freely permeable to ________ and ______ and impermeable to ____________.
ions
H2O
ions
proteins
29
What is the main difference between the ISF and the plasma?
the 7% of protein in plasma
(7g/dl)
30
What is the osmolarity of ECF?
It may be approximated by a 0.9% solution of NaCl,
which is 300 mOsm.
31
What is required for a net flow of water between compartments?
there has to be a difference in osmotic pressure
32
Do diffusible solutes contribute to the effective osmotic pressure of a solution? and why
No, diffusible solutes do not contribute to the effective osmotic pressure of a solution because they become equally distributed on the two sides of the membrane.
Only Non-Diffusible solutes contribute to the effective Osmotic Pressure of a solution
33
What is the Colloidal Osmotic Pressure?
Plasma Proteins are Non-Diffusible therefore, they can exert an osmotic effect and this is known as COP.
34
What is the colloidal osmotic pressure (C.O.P.) of
plasma?
25 mm Hg
35
What is the effect of an increase in COP on water
flow?
An increase in COP will cause more water to flow
into plasma.
36
What is the effect of a decrease in COP on water
flow?
A decrease in COP will cause more water to flow
into ISF.
37
What are the two major forms of fluid transport
across the capillary wall?
Filtration and osmotic flow
38
What determines how much water will flow into or
out of capillaries?
The Colloidal Osmotic Pressure of plasma
39
What is bulk flow?
Bulk flow is the flow of molecules subjected to a
pressure difference.
40
What is the magnitude of bulk flow proportional to?
hydrostatic pressure difference.
41
What is filtration?
Filtration is the bulk flow across a porous membrane which acts as a "sieve" withholding some particles.
42
What happens during filtration?
because fluid in the blood vessel is under pressure, it tends to “push out” fluid from inside the capillaries into ISF
43
What happens during osmotic flow?
plasma proteins, tends to “pull in” or retain fluid inside the capillaries
44
What is the name of the forces in filtration and osmotic flow?
The Starling Forces.
45
What determines the distribution of ECF volume
between the Plasma and ISF?
The Starling Forces.
46
What is the site where exchanges between plasma
and ISF take place?
Capillary Bed.
47
What are the capillary exchange? (2)
1- Nutrients, wastes, O2, CO2 move by simple diffusion
2- Starling’s Transcapillary Dynamics (Filtration and osmotic flow)
48
What is the role of lymphatic vessels ?
Lymphatic vessels drain about 10% of the excess fluid filtered out from capillaries
49
What is the lymphatic system? (4)
-The lymphatic system is a network of blind-ended terminal tubules
-which coalesce to form larger lymphatic vessels,
-which converge to form large lymphatic ducts,
-which drain into the large veins in the chest.
50
What is the composition of the walls of lymphatic vessels?
A single layer of endothelial cells.
51
What is the permeability of lymphatic vessels?
Highly permeable to all ISF constituents, including
proteins that may have leaked into the ISF from the
plasma.
52
What is the daily total blood flow?
6,000L.
53
What is the volume filtered into ISF on a daily basis?
What is the volume returned by absorption on a daily basis?
What is the volume returned by lymph drainage on a daily basis?
20L
17L
3L
54
What is the colloidal osmotic pressure (C.O.P.)?
It is the osmotic pressure due to plasma proteins,
which tends to "pull in" or retain fluid inside the
capillaries.
55
What does the osmotic pressure of a solution
depend on?
The number of osmotically active particles/unit volume, not their configuration, size, or charge.
56
What is the relationship between the osmotic pressure of a protein fraction and its concentration in the plasma?
It is directly related to its concentration in the plasma.
57
What is the relationship between the osmotic pressure of a protein fraction and its molecular weight?
It is inversely related to the molecular weight of that protein.
58
Which protein contributes the most to C.O.P.?
Albumin (smallest!)
59
What are the factors involved in transcapillary dynamics? (4)
hydrostatic pressure
C.O.P.
capillary permeability
lymphatic drainage.
60
What is edema?
Edema is the accumulation of excess fluid in the
interstitial spaces.
61
Under what conditions can edema develop? (4)
1. Increased Hydrostatic Pressure
2. Decreased Plasma Protein (i.e., C.O.P.)
3. Increased Capillary Permeability
4. Obstruction of Lymphatic Drainage
62
What is Kwashiorkor?
Kwashiorkor is a type of malnutrition characterized by severe protein deficiency. It causes fluid retention and a swollen, distended abdomen.
63
How does increased capillary permeability lead to
edema?
Normally, there is very little protein in ISF. If the capillary
wall becomes more permeable, some plasma proteins
escape into the ISF where they can exert an oncotic effect
64
What is Elephantiasis?
blockage of lymphatic
drainage resulting from
parasite infestation
65
What are the roles of plasma proteins ? (3)
1. Determining the distribution of fluid between the plasma and the ISF compartments by Starling Forces controlling transcapillary dynamics
2. Contribute to the viscosity of plasma (Viscosity contributes to blood pressure)
3. Contribute to the buffering power of plasma
66
What is the function of fibrinogen (and some globulins)?
are essential to clotting
67
What is the function of gamma-globulins (Immunoglobulins)?
provide specific resistance to infection
68
What is the function of albumin (and some globulins) ?
act as carriers for lipids, minerals, hormones
69
What are the different types of blood cells?
Red Blood Cells (Erythrocytes) Platelets (Thrombocytes)
White Blood Cells (Leukocytes).
70
What is the lifespan of red blood cells?
120 days
71
What is hematopoiesis?
The process of blood cell formation.
72
What is erythropoiesis?
The production of red blood cells.
73
What is thrombopoiesis?
The production of platelets.
74
What is leukopoiesis?
The production of white blood cells.
75
What are cytokines?
Substances (proteins or peptides) which are released by one cell and affect the growth, development, and activity of another cell.
76
What are hematopoietic growth factors (HGFs)?
Cytokines that influence the proliferation and
differentiation of blood cell precursors.
77
What is the general pattern of hematopoiesis?
1. An inducer will generate self-replication of a Pluripotential
Multipotential Stem Cell, which will divide and gives rise to three types of committed stem cells.
2. The committed stem cells differentiate along only one path : Leukopoiesis, Thrombopoiesis or Erythropoiesis
78
What are the two things happening during hematopoiesis?
1. Division
2. Differentiation
79
What are the sites of hematopoiesis in the prenatal
period? (3)
Beginning : in the yolk sac
At 1 month : Liver&spleen
Half-pregnancy: Bone narrow
80
What are the sites of hematopoiesis in the postnatal
period?
20-25 years: Distal long bones
Rest of your life: Axial skeleton
81
What makes up the axial skeleton? (7)
Flat bones of skull
Shoulder blades
Sternum
Vertebrae
Ribs
Pelvis
Proximal epiphyses of long bones
82
What are the ends of the bone and the middle part called?
epiphysis
diaphysis
83
What is the function of RBCs?
facilitate the transport of respiratory gases.
84
What is the shape of RBCs?
RBCs have a biconcave disk shape.
85
What is the advantage of the biconcave disk shape
of RBCs? (2)
The biconcave disk shape of RBCs allows for :
-maximal surface area and minimal diffusion distance, increasing the efficiency of O2 and CO2 diffusion.
-High degree of flexibility
86
What is the shape of RBCs due to?
Shape due to presence of “spectrin” (a fibrous protein, forming a flexible network linked to cell membrane)
87
What is a CBC?
complete blood count
(RBC, WBC, platelet count, Hematocrit, Hb concentration)
88
What is an Normocytic cell?
What is an Microcytic cell?
What is an Macrocytic cell?
Normal size RBCs
Smaller than normal size RBCs
Larger than normal size RBCs
89
What is a Sickle cell?
What is a Spherocyte?
RBCs C-shaped farm tool called a “sickle.”
RBCs sphere-shaped rather than bi-concave
90
Do RBCs contain subcellular organelles?
No
91
What is the rate of production and destruction of RBCs?
Rate of production = Rate of destruction ~2 x
10^6/second.
92
Which gender has more RBCs?
Males
93
What are the important enzyme systems found in RBCs? (2)
RBCs have :
-glycolytic enzymes that generate energy anaerobically
-Carbonic anhydrase that aids in CO2 transport.
94
How many O2 molecules can each molecule of Hb bind?
4
95
What happens when Hb combines with O2?
When Hb combines with O2, it forms HbO2 and appears bright red.
(Oxyhemaglobin)
96
What is the structure of hemoglobin?
Each hemoglobin molecule is made up of four heme groups surrounding a globin group.
(usually 2 alpha chain and 2 beta chain). Each Heme group has an iron which allows the O2 to bind.
97
What is the molecular weight of hemoglobin?
64 KDa
98
What is the solubility of O2 in plasma and blood?
O2 solubility in plasma is very low at 0.3 ml O2/100 ml plasma, but due to Hb, O2 solubility in blood is high at 20 ml O2/100 ml blood.
99
What are the functions of Hemoglobin? (3)
Transport of O2
Transport of CO2
Acts as a buffer
100
Why is Hb found inside RBCs rather than dissolved
in plasma? (3)
If there were no RBCs:
Plasma Viscosity would increase
Plasma C.O.P. would increase
Hb would be lost via the kidney (like albumin).
101
What is the O2 carrying capacity of blood per 100ml when Hb is fully saturated with O2?
20 ml O2/100 ml blood.
(When Hb is fully saturated with O2, each gram of Hb holds 1.34 ml O2 --- 15g x 1.34ml = 20)
102
When Hb is fully saturated with O2, each gram of Hb holds how much ml of O2 ?
When Hb is fully saturated with O2, each gram of Hb holds 1.34 ml O2
103
What are the factors affecting the ability of Hb to
bind and release O2? (5)
1. Temperature
2. Ionic Composition
3. pH
4. pCO2
5. Intracellular enzyme concentration
104
What is the process of RBC precursor proliferation? (3)
-Division and differentiation over 3-5 days
-followed by the formation of reticulocytes over 24 hours
-which then mature into RBCs by decreasing in size, losing their nucleus and organelles, and
accumulating Hb.
105
True or False : Injection of Bone Marrow Stem Cells can reconstitute some Hematopoietic Cell Types.
False.
Injection of Bone Marrow Stem Cells can reconstitute ALL Hematopoietic Cell Types.
106
What is the normal reticulocyte count?
Less than 1%
107
What does the reticulocyte index reflect?
The amount of effective erythropoiesis in the bone
marrow.
108
What are the factors that determine the number of
RBCs? (2)
Oxygen requirements
Oxygen availability
109
What is erythropoietin (EPO)?
A glycoprotein hormone/cytokine produced mainly by the kidney responsible for stimulating the production of red blood cells
110
What is the stimulus for the release of EPO?
Hypoxia, (which may result from decreased RBC count, decreased availability of O2 to blood, or
increased tissue demand for O2.)
111
What is the regulation of erythropoiesis?
Increased erythropoietin in plasma stimulates RBC
production in bone marrow. And when it senses the increased oxygen in plasma, It decreases the release of erythropoietin.
Its release is stimulated by hypoxia and regulated
by negative feedback.
112
What happens to old red blood cells?
They are recognized as such and removed from circulation by macrophages in the liver and spleen through phagocytosis.
113
What is the effect of testosterone on erythropoietin
release? (2)
-It increases the release of erythropoietin.
-increases sensitivity of RBC precursors to Erythropoietin
114
What is the effect of estrogen on erythropoietin release?
-It decreases release of erythropoietin.
-decreases sensitivity of RBC precursors to Erythropoietin
115
What prolongs RBCs lifespan?
Nothing
116
What is phagocytosis of old RBCs? (3)
It is the process by which macrophages engulf old RBCs and digest them, and release their contents (globin, Fe, and Hb)
117
What happens to globin after RBC digestion?
released in amino acid pool
118
What happens to iron after RBC digestion?
Picked up by transferrin and stored in the liver, spleen and gut with Ferritin.
119
Why does iron need transferrin to transports itself?
because iron by itself is toxic
120
What happens to Hb after RBC digestion?
Heme group is converted to bilirubin which gives plasma it's yellow color.
121
How is bilirubin removed from the body?
The liver takes the bilirubin from the blood and changes its chemical make-up so that most of it is passed through poop as bile.
122
A higher concentration of bilirubin in the plasma gives a condition called...
Jaundice
123
What is neonatal jaundice?
Bilirubin is normally processed by the liver, but a newborn's liver takes a few days to process it, newborns may have some degree of jaundice.
(excess blood cells, a lot of hemolysis)
124
What is a solution to neonatal jaundice?
Phototherapy : it's is the use of visible light for the treatment
125
What are the cause of jaundice? (3)
1. Excessive Hemolysis
2. Liver Damage
3. Bile Duct Obstruction
126
What is the normal level of bilirubin in the blood?
1mg/dL.
127
What is polycythemia?
Polycythemia is a condition characterized by an increase in the number of RBCs in the blood.
128
Who am I?
An abnormal dynamic for RBC where Production > Destruction
polycythemia
129
Who am I?
An abnormal dynamic for RBC where Production < Destruction
anemia
130
What are the clinical indices to evaluate the abnormal dynamics of RBCs? (3)
⎼ Number of RBCs
⎼ Amount of Hb
⎼ Hematocrit
131
What is something that could APPEAR as polycythemia after evaluating the hematocrit?
Dehydration
(less body water, less plasma)
132
What is something that could APPEAR as anemia after evaluating the hematocrit?
Fluid retention
(more plasma)
133
What is the difference between absolute and relative polycythemia?
Absolute polycythemia is due to physiological or pathological reasons, while relative polycythemia is due to decreased plasma volume.
134
What are some causes of physiological polycythemia? (4)
- at high altitude
- increased physical activity
- chronic lung disease
- heavy smoking
135
What is physiological polycythemia?
Is a secondary effect that occurs due to higher O2 needs or lower O2 availability
136
What is pathological
polycythemia?
It is a primary effect that can occur due to tumors of cells producing EPO or unregulated RBC production by bone marrow.
137
Why is Polycythemia a problem? (2)
– increases blood viscosity
– slow blood flow can lead to blood clots
138
What are the measurements defining Anemia? (2)
Decreased RBC count and decreased Hb content.
139
What is anemia?
A decrease in the oxygen-carrying capacity of blood
140
What are the classifications of anemia by size and color?
Size:
Microcytic
Normocytic
Macrocytic
Color:
Normochromic
Hypochromic
141
What are the three etiologic classifications of Anemias? (causes) (3)
1. Diminished Production
2. Ineffective Maturation
3. Increased RBC Destruction/
Reduced RBC Survival
142
What causes Diminished Production of RBCs (anemia)? (3)
– Abnormality at site of production (bone marrow)
– Inadequate stimulus
– Inadequate raw materials
143
What am I? An anemia caused by Abnormality at site of production (bone marrow)
Aplastic (Hypoplastic) Anemia
144
What am I? An anemia caused by an unknown exposure to radiation chemicals or drugs
Aplastic (Hypoplastic) Anemia
145
What do the RBCs of Aplastic (Hypoplastic) Anemia look like?
Normocytic, Normochromic
146
What am I? An anemia caused by renal disease (inadequate stimulus (EPO))
Stimulation Failure Anemia
147
What do the RBCs of Stimulation Failure Anemia look like?
Normocytic, Normochromic
148
What am I? An anemia caused by increased requirement for Fe or inadequate supply of Fe (Inadequate raw materials)?
Iron Deficiency Anemia
149
What am I? The most common type of anemia
Iron Deficiency Anemia
150
What could cause an increased requirement for Fe or inadequate supply of Fe ?
increased requirement for Fe:
(infancy, adolescence, pregnancy)
inadequate supply of Fe:
(dietary deficiency, failure to absorb, loss of Fe in hemorrhage)
151
What do the RBCs of Iron Deficiency Anemia look like?
Microcytic, Hypochromic
152
What is the daily intake of Fe required in the diet?
~15-20 mg.
153
What is the daily absorption of Fe from the gut?
Males: ~1 mg Fe/day
Females who menstruate: ~2 mg Fe/day
154
There is 4g of iron in the body. How is it distributed? (4)
65% Hb
30% stored
5% myoglobin
1% enzymes
155
What is the amount of Fe required for normal
erythropoiesis?
25 mg Fe/day.
156
What is the amount of Fe released during normal
RBC destruction? What is the amount of Fe lost per day? What is the amount of Fe recycled per day?
25 mg Fe/day.
lost : 1 mg Fe/day.
recycled : 24 mg Fe/day.
157
What is the menstrual loss of blood?
~50 ml blood/month
158
How much iron do menstruating females lose?
1g Hb contains 3.5 mg Fe, 15g Hb/100 ml of blood is ~50 mg Fe.
Therefore, menstruating females lose ~25 mg Fe/month
159
What am I? An anemia caused by Deficiencies of Vitamin B12 and Folic Acid or Inadequate supply of Fe ( Ineffective Maturation)
Maturation Failure Anemia
160
What are Deficiencies of Vitamin B12 and Folic Acid caused by ?
B12:
Usually, failure to absorb
Folic Acid:
Usually, dietary absence, overcooking vegetables
161
How is Vitamin B12 absorbed?
vitamin B12 needs to combines with a protein made by the stomach, called intrinsic factor, and the body absorbs them together.
162
What am I? An anemia caused by Intrinsic Factor Deficiency
Pernicious Anemia
163
What am I? An anemia caused by Increased RBC Destruction/
Reduced RBC Survival
Hemolytic Anemias
164
What are the types of Hemolytic Anemias?
-Abnormal RBC Membrane Structure
-Abnormal Enzyme Systems
-Abnormal Hb structure
165
What is Thalassemia?
Hemolytic Anemia
Abnormal Hb structure-deficient synthesis of globin amino acid chains
166
What are the causes of Hemolytic Anemias? (2)
Congenital
Acquired
167
What is the accumulation of blood in tissues?
Hematoma
168
What is the process that begins within seconds of injury and lasts only minutes?
Primary Hemostasis.
169
What is the process that occurs after primary hemostasis and involves blood clot formation?
Secondary Hemostasis.
170
What is the term for the arrest of bleeding following vascular injury?
Hemostasis
171
What are the steps of hemostasis? (3 following injury)
-Vasoconstriction
-Platelet Plug Formation
-Blood Clot Formation
172
What happens during vascular response?
-vasoconstriction : Smooth muscle cells in vessel wall respond to injury by contracting
-Opposed endothelial cells stick together
173
What is the structure of platelets? (4)
- no nucleus
-Many granules – (containing factors for vasoconstriction, platelet aggregation, clotting, growth, etc. Many filaments, microtubules, mitochondria, sER)
-Life Span: 7 - 10 days
- ~ 2-4 µm diameter
174
What is the process of Thrombopoiesis? (4)
-Pluripotent hematopoietic stem cell
-Committed Myeloid stem cell
-Megakaryocyte
-Platelets
175
What is the hormone responsible for stimulating platelet production, mostly from the liver?
Thrombopoietin (HGF)
176
Explain the platelet plug formation.
the vessel damage leads to altered/damaged endothelial surface which exposes the collagen.
This triggers the adhesion of platelets which allows platelet activation and aggregation.
The activation releases mediators : ADP, TXA2, serotonin, PF3. These mediators allow the aggregation of the platelets.
The platelets adhere to collagen thanks to Von Willebrand Factor, secreted by platelets and endothelium cells.
The aggregation allows to form the platelet plug.
177
What is the other pathway in the platelet plug formation? and why is it there?
The platelet plug is a temporary structure. If we really want to stop bleeding, we need to form a blood clot. And so we'll see that the damaged endothelial cells and cells outside the damaged vessel are going to lead to activation of another pathway : A coagulation pathway which allows the release of thrombin. And Thrombin is important for the production of the blood clot.
178
Exposed collagen ________ & __________ platelets.
Platelet factors are _________ & _________ more platelets
Platelet factors also promote ______________ scheme
binds
activates
released
attract
coagulation
179
What are the platelet functions? (5)
– Release vasoconstricting agents / cytokines
– Form Platelet Plug (White Thrombus)
– Release Clotting Factors
– Participate in Clot Retraction
– Promote Maintenance of Endothelial Integrity
180
What are petechia?
Petechia are small red or purple spots caused by
bleeding into the skin due to capillaries and
platelets not functioning properly.
181
What causes Abnormal Primary Hemostatic Response?
– Failure of Blood Vessel to Constrict
– Platelet Deficiencies
182
What are the causes of Platelet Deficiencies? (2)
congenital
acquired :
-Drugs, Toxins, Antibodies
-Aspirin (in small doses)
183
What is thrombocytopenia?
Thrombocytopenia is a condition characterized by
low numbers of platelets
184
What is the mechanism of action of aspirin in
platelet deficiencies?
Aspirin (in small doses) inhibits the synthesis and release of TXA2.
185
Are RBCs necessary for the process of clotting?
No
186
What initiates clotting?
Clotting is initiated by injury to the blood vessel wall.
187
What does clotting result in?
results in sequential activation and interaction of a group of plasma proteins/clotting factors, (acting as enzymes or co-factors), in the presence of Ca++ and some phospholipid agents.
188
Explain the intrinsic pathway of clotting.
The vessel damage leads to exposed collagen, it leads to interacting plasma factors plus Ca++ and PF3, which leads to prothrombinase (convert Prothrombin into Thrombin with Ca++). Thrombin allows to convert fibrinogen into fibrin which allows to form the blood clot.
189
Explain the extrinsic pathway of clotting.
The vessel damage leads to subendothelial cells exposed to blood, it leads to interacting plasma factors plus Ca++ and PF3, which leads to prothrombinase (convert Prothrombin into Thrombin with Ca++). Thrombin allows to convert fibrinogen into fibrin which allows to form the blood clot.
190
How long is the intrinsic pathway ?
3-6min
191
How long is the extrinsic pathway?
15-20sec
192
The small amounts of _________ generated rapidly in the _________ Pathway, are sufficient to trigger strong ___________ feedback effects to generate larger quantities of __________ in the ___________ Pathway.
Thrombin
Extrinsic
positive
Thrombin
Intrinsic
193
What are the 3 factors in coagulation?
Ca++
Phospholipid
Protein Plasma Factors
194
What are the causes of Clotting Factor Deficiencies?
-Congenital
Single-factor Hereditary deficiencies
(factor VII, hemophilia)
-Acquired
Multi-factor deficiencies
(liver disease, Vit.K deficiency)
195
What is the role of Vitamin K in the synthesis of
clotting factors?
Vitamin K is a cofactor in the synthesis of Prothrombin, VII, IX, and X.
196
What is the contractile protein required for clot
retraction?
Thrombosthenin
197
What is the process of clot lysis also known as?
Thrombolysis
198
What are the two types of proactivators involved in clot lysis?
Intrinsic proactivators (Factor XIIa and endothelial
cell factors) and extrinsic proactivators (tissue
factors)
199
What is the inhibitor of platelet adhesion?
aspirin
200
What are the anticoagulant drugs that interfere with clot formation? and how
– Coumarin – blocks synthesis of functional Prothrombin, VII, IX, X
– Heparin – inhibits THROMBIN activation and action
201
What are the thrombolytic drugs that promote clot lysis?
– Tissue Plasminogen Activator (tPA)
– Streptokinase
202
Explain the process of clot lysis.
The plasminogen activators and plasminogen lead to plasmin and soluble fibrin fragments. The fibrin leads to soluble fibrin fragments.
