Lecture 15 Blood and Hemostasis Flashcards
1
Q
What is the optimal physiological pH range of a red blood cell?
A
7.35 - 7.45
2
Q
What 3 layers will blood separate into after treated with heparin and then centrifuged?
A
Top Layer - Plasma (supernatant
Middle Layer - Buffy Coat (leukocytes & platelets, 1%)
Bottom Layer - RBCs (hematocrit) (precipitate)
3
Q
What is serum?
A
Serum is plasma without the blood-clotting proteins.
*Book Definition -> a proteins-rich fluid LACKING FIBRINOGEN, but containing albumin, immunoglobulins, and other components.
4
Q
What is plasma?
A
Plasma is blood minus he formed elements.
*Book Definition -> contains albumin, fibrinogen, immunoglobulins, lipids (lipoproteins), hormones, vitamins, and salts as predominant components.
5
Q
What is the difference between plasma and serum?
A
Serum is essentially fibrinogen-free plasma (blood clotting protein).
When blood is collected in a test tube without an anticoagulant and left to coagulate, the fluid portion that is on top of the blood clot that forms at the bottom is SERUM.
6
Q
What is the average hematocrit percentage in males?
A
47%
7
Q
What is the average hematocrit percentage of blood in females?
A
42%
8
Q
How many liters of total blood do women have? How about men?
A
Female: 4-5 liters
Male: 5-6 liters
9
Q
True of False:
Fibrinogen and Albumin are both made in the liver.
A
True: both fibrinogens and albumin blood proteins are made in the liver.
10
Q
The blood protein, globulins, are found in the blood as _____, which are crucial to our immune system?
A
immunoglobulins
11
Q
What is the main function of the blood protein, albumin?
A
To exert major osmotic pressure on blood vessel walls.
12
Q
What is the major function of fibrinogen, and what is it a target for?
A
Main Function -> involved in blood clotting
Target For -> Thrombin
13
Q
What protein, that is produced by the kidney, stimulates an increase in erythrocytes?
A
Erythropoietin
14
Q
True or False:
The erythrocyte is devoid of organelles, but has granules?
A
False, the erythrocyte is devoid of granules and organelles.
15
Q
What are the major contents found in an erythrocyte?
A
- lipids
- ATP
- carbonic anhydrase
- hemoglobin
16
Q
Of the proteins that are found in erythrocytes, what percent are integral membrane proteins?
A
about 50%
17
Q
What are the two specific peripheral proteins, found in the erythrocyte, that we are interested in?
A
*Spectrin
Actin (bound via ankyrin)
18
Q
What calmodulin-binding protein stimulates the association of actin with spectrin?
A
Adducin
19
Q
What are the two major transmembrane proteins exposed to the out surface of the erythrocyte?
A
Glycophorin and Anion Transporter Channel (band 3)
20
Q
What is the function of ankyrin in the erythrocyte?
A
Ankyrin anchors spectrin to band 3 (anion transporter channel).
**Ankyrin links the spectrin-actin network and the plasma membrane by binding to spectrin and a transmembrane protein (band 3).
21
Q
What is the function of protein 4.1 in erythrocytes?
A
Protein 4.1 links the actin-tropomyosin complex to glycophorin.
**Protein 4.1 is another link that binds spectrin-actin junctions and the transmembrane protein glycophorin.
22
Q
What have RBCs been useful for in the laboratory to study?
A
The Cortical Cytoskeleton
23
Q
What is the function of band 3 (anion transporter channel) in the erythrocyte?
A
Band 3 allows bicarbonate to cross the plasma membrane in exchange for chloride. This exchange facilitates the release of carbon dioxide in the lungs.
24
Q
What is the principle determinant of the shape of RBCs?
A
The Cortical Cytoskeleton
25
What is the major structural protein of erythrocytes?
Spectrin
26
Describe the structure of the main structural protein, spectrin?
Spectrin is a tetramer of two polypeptide chains, alpha & beta.
The end of the spectrin tetramers associate with short actin filaments, resulting in the spectrin-actin network.
*From Book:
Spectrin is large dimeric protein consisting of alpha and beta polypeptides.
-two polypeptides associate in antiparallel pairs to form a rod
-two chains join head to head to form a tetramer
>which is found in cortical region of RBC
27
The interaction between which two proteins of the RBC is disrupted in the condition, hereditary spherocytosis (HS)?
Spectrin alpha & beta and protein 4.1
* In Hereditary Spherocytosis --> RBCs are spheroidal, less rigid, of variable diameter and subject to destruction in the spleen.
- this alteration is caused by cytoskeleta labnormalities involving sites of interactions between spectrin (alpha & beta) and protein 4.1
28
What is the purpose of the biconcave disc shape in RBCs?
To increase surface area.
29
How many calcium binding domains does the spectrin tetramer have?
2
30
What is the key characteristic that's used to help identify neutrophils?
3-5 nuclear lobes with connecting strands.
31
How long do neutrophils typically live after they leave the circulatory system?
1-2 day life span after leaving circulation.
32
How many microns is the typical neutrophil?
7-9 microns
33
How many hours does neutrophils remain in circulation?
10-12 hours.
34
What is the function of neutrophils?
Neutrophils migrate to the sites of infection where they recognize and phagocytose bacteria.
35
After leaving the circulation through postcapillary venules and entering the connective tissue, what is the neutrophil function?
Neutrophils act to eliminate opsonized bacteria or limit the extent of an inflammatory reaction in the connective tissue.
36
What enzymes does the neutrophil secrete?
A class of enzymes capable of destroying certain bacteria by formation of free radicals (superoxide)
Also, release of lysozyme and lactoferrin, which destroy bacterial walls.
37
Which two enzymes released by neutrophils destroys bacterial walls?
Lysozyme
Lactoferrin
38
True or False:
Neutrophils have small, numerous specific (secondary) granules in their cytoplasm.
True
39
True or False:
Neutrophils have larger, more numerous azurophilic granules than it does small, numerous specific (secondary) granules.
False - neutrophils have larger, less numerous azurophilic granules than it does small, numerous specific (secondary) granules.
40
What stain is typically used to stain the cytoplasmic granules of Neutrophils?
Wright-Giemsa Stain
41
What does primary (azurophilic) granules of neutrophils contain?
elastase
defensins
myeloperoxidase
42
What do the secondary (specific) granules of neutrophils contain?
lysozyme
lactoferrin
gelatinase
other proteases
43
How many microns is the basophil in size? Also, what other white blood cell is also this size?
7-9 microns
The same size as the neutrophil.
44
How many lobes does the basophil nucleus have?
Lobulated nucleus (bilobed)
45
What 3 vasoactive substances does the basophil secrete from its large, membrane-bound basophilic granules?
serotonin
heparin (anticoagulant)
Kallikrein (attracts eosinophils)
46
What other active molecule besides vasoactive substances does basophils produce in their large, membrane-bound basophilic granules? (HINT: the molecule is derived from arachidonic acid)
Leukotrienes
47
What do leukotrienes function to do when released from the basophil granules?
1) increase vascular permeability
| 2) slow contraction of smooth muscles
48
What percentage of total leukocytes do basophils represent?
less than 1%
49
If your patient presented to the clinic with a basophil count of more than 150 basophils/microliter, what conditions would you suspect was causing this?
* acute hypersensitivity reactions
* viral infections
* chronic inflammatory conditions (rheumatoid arthritis and ulcerative colitis)
50
Does the basophil have more secondary or primary granules?
secondary (specific) granules --> are large and stain dark blue or purple.
51
What do basophils express on their surface?
* immunoglobin E (IgE)
* c-kit receptor
* CD49b
52
Besides expressing IgE, c-kit receptor, and CD49b on their surfaces, what do basophils release to mediate allergic reactions when activated by antigen binding?
Histamine
53
How many microns is the eosinophil in size?
9-10 microns
54
How many lobes does the eosinophil nucleus have?
2 (bilobed nucleus)
55
What are the 3 proteins that eosinophil specific (secondary) granules produce?
1) Major Basic Protein (MBP)
2) Peroxidase (eosinophil peroxidase (EP))
3) Cationic Protein (eosinophil cationic protein (ECP))
**From Book: 4) Eosinophil-derived neruotoxin (EDN)
56
What does major basic protein (MBP) function to do after being released from specific (secondary) granules of eosinophils?
MBP disrupts parasite membranes
MBP causes basophils to release histamine
57
What protein released by eosinophils stimulates basophils to release histamine?
Major Basic Protein (MBP), which causes basophils to release histamine by a calcium-dependent mechanism.
*MBP also disrupts parasite membranes
58
What are the two main conditions in which eosinophils respond too?
1) allergic diseases
| 2) parasitic infections
59
True or False:
Eosinophils phagocytize antibody-antigen complexes and parasites.
True
60
What percentage do eosinophils represent of total leukocyte presence?
1%-5% of total leukocytes.
61
True or False:
Eosinophil cytoplasm contains large, refractile primary granules that appear bright red and are clearly discernible.
False - eosinophil cytoplasm contains large, refractile SPECIFIC (secondary) granules that appear bright red and are clearly discernible.
62
What does cationic protein (eosinophil cationic protein) that is releases by eosinophils do?
1) neutralizes heparin
| 2) together with MBP, it causes the fragmentation of parasites.
63
What does eosinophil peroxidase do that is released by the eosinophil?
It binds to microorganisms and facilitates their killing by macrophages.
64
What percentage of total leukocyte count does neutrophils make up?
60%-70% of total leukocytes
65
True or False:
Under the microscope a histologist can determine if a lymphocyte is a B lymphocyte of T lymphocyte.
False - cannot be determined by looking through microscope.
66
What cell type is the B-lymphocyte a precursor of?
Precursor of Plasma Cell
67
What cell type is the T-lymphocyte a precursor of?
Precursor of T-lymphocyte
68
How many microns is a large lymphocyte?
18 microns
69
# Fill in the Blank:
Medium lymphocytes are _____microns.
10-12 microns
70
True or False:
The small lymphocyte is 6-8 microns in size.
TRUE
71
What is the characteristic of the lymphocyte nucleus?
Large round, sometimes slightly indented nucleus; fills most of cell.
72
What is the micron size of a typical monocyte?
9-12 microns
73
What is the largest cell type in the leukocyte family?
Monocyte
74
What characteristic shape does the nucleus of the monocyte have?
eccentrically located, kidney-shaped nucleus
75
What two cell types is the monocyte a precursor for?
Precursor of Macrophages and Osteoclasts
76
True or False:
The monocyte has a granular cytoplasm due to small lysosomes.
True
77
What are platelets derived from?
platelets are derived from megakaryocytes
78
How many platelets are typically found per microliter of blood?
200,000-400,000/microliter of blood
79
What protein is involved in the adhesion of platelets?
integrins
80
# Fill in the Blank:
Platelets release ______ which increases platelet aggregation
Thromboxane
81
What do endothelial cells release that decrease platelet aggregation?
prostacyclin
82
True or False:
Platelets repair damage to endothelium by forming platelet plug.
True
83
True or False:
Platelets enhance aggregation by release of factors, and promote clot formation, retraction, and dissolution.
TRUE
84
What 3 types of granules do platelets have?
alpha granules
dense core granules
lysosome granules
85
What does the lysosome granule of platelets release?
Thrombus Dissolution
86
What does the Dense Core Granule of platelets release?
Mediators of the vascular tone
- serotonin
- calcium
- ADP
87
What does the alpha granule of platelets release?
Proteins with hemostastic function
- fibrinogen
- thrombospondin
- plasminogen
Growth factors
- PDGF
- TGF-alpha
- TGF-beta
Microbicidial proteins
- thrombocidins
- kinocidins
88
Which organ within the body synthesizes most of the proteins of the clotting cascade?
The Liver
89
What is hemostasis?
Hemostasis is the elimination of bleeding.
90
In which vessels does the most effective mechanisms for hemostasis occur?
Small vessels such as:
- capillaries
- arterioles
- venules
91
What is an accumulation of blood in tissues?
Hematoma
92
What is the hemostatic sequence of events in small vessels?
* constriction of smooth muscles around vessels
* constriction of vessels
* slowing of blood
* formation of platelet plug
* blood clotting (coagulation)
93
Why do platelets normally not adhere to endothelial cells that line the blood vessel walls?
Because untraumatized platelets produce prostacyclin from arachidonic acid, which decreases platelet aggregation.
94
When an injury occurs to the endothelial lining, what is exposed that has a negative charge and platelets bind to, thus causing the platelets to release the contents of their secretory vesicles, and also cause the conversion of arachidonic acid in the platelet plasma membrane to thromboxane A2?
Collagen
95
ADP is a molecule released from the platelet secretory vesicle upon binding to exposed collage. What is it's function?
ADP attracts other platelets to the site of injury.
96
What does thromboxane A2 do during hemostasis?
Causes vasoconstriction and platelet aggregation.
97
True or False:
ADP and other factors cause the platelets to aggregate, forming a plug.
True
98
What factor is a plasma protein, released from Weibel-Palade bodies in endothelial cells, that facilitates the adherence of platelets to the walls of the damaged blood vessels?
Von Willebrand Factor
99
Where is Von Willebrand Factor released from?
Weibel-Palade bodies in endothelial cells.
100
What does von Willebrand Factor do?
Facilitates the adherence of platelets to the walls of the damaged blood vessels.
101
What is the inactive form of thrombin and by which factor is it activated to its active form by?
Prothrombin
Factor XII
102
How is Factor XII activated so that it can in-turn activate prothrombin, which is always found in the blood of normal individuals?
Factor XII is activated wen it contacts collagen in the damaged vessel wall.
103
True or False:
Thrombin catalyzes the conversion of fibrinogen to fibrin.
True
104
Which protein catalyzes the conversion of fibrinogen to fibrin?
Thrombin
105
You already know that fibrinogen is converted to fibrin by thrombin, which is the active form of prothrombin and is converted to thrombin by Factor XII, but what is the role of fibrin?
Fibrin is a mesh-work in which platelets, blood cells, and plasma become entrapped to from the actual clot.
*The fibrin meshwork forms in the presence of Factor XIII, which is also activate by thrombin.
106
Fibrinogen is always present in the blood of normal individuals, but in what organ is it synthesized?
The Liver
107
What are the 3 phases in blood clotting (hemostasis)?
Phase 1: adhesion of platelets to the sub-endothelium of an injured blood vessel
Phase 2: aggregation of platelets to form a hemostatic plug
Phase 3: platelet procoagulation activity terminates with the removal of the fibrin clot
108
What is going on during reshaping of the clot by polymerization of fibrin?
* fibrinogen is split into a number of polypeptides by thrombin
* these polypeptides are then chemically linked by the enzymatic action of Factor XIII
* RBCs and other cells are trapped in this mesh and become part of the clot.
109
What activated factor does the common pathway begin with?
Factor X
110
What does the common pathway end with?
The conversion of fibrinogen to fibrin, followed by cross-linking of fibrin by activated Factor XIII.
111
The synthesis of factors VII, IX, and X require which vitamin?
Vitamin K
112
Most of the clotting factors are synthesized in which organ?
Liver
**thus any liver dysfunction may affect the clotting mechanism
113
Objective 6 - be able to identify each type of blood cell (RBCs and WBCs) as presented on slides in class.
Practice looking through slides of cells in class lecture PDFs.
114
How is the homing mechanism activated for leukocyte extravasation?
Homing mechanism is activated by various cytokines released by mast cells, platelets, and damaged tissue cells.
115
What is released by endothelial cells to increase vascular permeability during leukocyte extravasation?
Nitric Oxide (NO)
116
Which type of blood flow do the leukocytes (e.g, neutrophils) leave when they move toward the endothelium of the vessel wall?
Laminar Flow
117
Which 2 cell adhesion molecules are involved in leukocyte extravasation?
Selectin & Integrin
118
What percent of the body's total weight does blood make up?
About 8%
119
What causes the leukocytes to roll along the endothelium?
Binding of ligands to the P-selectins causes leukocytes to roll along the endothelium.
120
What activates the P-selectin to appear on the cell surface of endothelial cells?
When endothelial cells are activated by inflammatory signaling.
121
What domain on the P-selectins does oligosaccharide ligands on the leukocytes bind to?
Oligosaccharide ligands on leukocytes bind to carbohydrate recognition domains (CRDs) on the P-selectins.
122
What specific antigen is oligosaccharide ligands for P-selectin binding found on leukocyte membranes?
Sialyl Lewis-x Antigens
123
Is the integrin receptor on the leukocyte membrane or endothelium? Also, what binds to the integrin receptor?
Integrin receptors are activated on leukocyte membrane.
Integrin receptors bind to ICAM-1 and ICAM-2 (Ig superfamily) on endothelial cells.
124
What binds to VCAM and ICAM on endothelial cell membranes during the leukocyte extravasation?
Integrins beta1 and beta2, which are activated on leukocyte membranes.
125
What promotes the transendothelial migration of leukocytes?
Integrins interaction with endothelial ligands promote the transendothelial migration of leukocytes.
126
What is erythroblastosis fetalis?
erythroblastosis fetalis is an antibody-induced hemolytic disease in the newborn that is cause by blood group incompatibility between mother and fetus.
127
Which antigen is the major cause of Rh incompatibility?
D antigen
128
What can hemolysis in erythroblastosis fetalis result in?
1) Hemolytic anemia - causes hypoxic injury to the heart and liver leading to generalized edema (hydrops fetalis)
2) Jaundice - causes damage to the CNS
3) Hyperbilirubinemia -
129
What are Rh negative mothers given soon after delivery of an Rh positive baby to mask the antigenic sites on the fetal RBCs that my have leaked into the maternal circulation during childbirth?
Anti-D Globulin
130
Why does the initial exposure to the Rh antigen during the first pregnancy not cause erythroblastosis fetalis?
Because IgM is produced and these are too large to cross the placenta.
131
If the first pregnancy is not is danger because IgM does not cross the placenta, then why is the second and third pregnancies at risk?
Because subsequent exposure to D antigen during the second and third pregnancy leads to a strong IgG response, and IgGs can cross the placenta.
