Erythrocytes Flashcards
1
Q
Specialized connective tissue in fluid, extracellular matrix (plasma)
A
blood
2
Q
How much does plasma constitute of blood volume?
A
55%
3
Q
What is the purpose of protein in blood?
A
viscosity
4
Q
plasma - clotting factors =
A
serum
5
Q
Blood is the primary vehicle for what?
A
transport of nutrients, O2, CO2, waste products, hormones
6
Q
What does blood function in?
A
thermoregulation and homeostasis
7
Q
what is the avg blood volume in adults?
A
5 L
8
Q
What are the 3 plasma proteins?
A
albumins
globulins
fibrinogens
9
Q
make up bulk of plasma proteins, all synthesizes in liver
A
albumins
10
Q
Where are albumins synthesized?
A
liver
11
Q
What is the function of albumins?
A
function as transport proteins for insoluble metabolites (FA)
12
Q
Albumins are responsible for maintaining what?
A
colloid osmotic pressure in blood vessels
13
Q
Large plasma protein molecules that are used as transport proteins for lipids and heavy metal ions
A
globulins
14
Q
What do globulins transport?
A
lipids and heavy metal ions
15
Q
largest plasma proteins that are soluble and synthesized by liver
A
fibrinogens
16
Q
Are fibrinogens soluble or insoluble?
A
soluble
17
Q
Which organ synthesizes fibrinogen?
A
liver
18
Q
plasma protein that polymerizes to form insoluble fibrin during clotting
A
fibrinogens
19
Q
Fibrinogens polymerize to form what?
A
insoluble fibrin
20
Q
process of converting fibrinogen to fibrin
A
prothrombin –> thrombin catalyzes fibrinogen –> fibrin
21
Q
What catalyzes fibrinogen?
A
thrombin
22
Q
What makes up the formed elements (“blood cells”)?
A
RBCs
WBCs
platelets
23
Q
Where are the formed elements formed and how?
A
bone marrow via hemopoesis
24
Q
volume of RBCs is know as:
A
hematocrit
25
what is the hematocrit in males vs females:
45% males
| 42% females
26
genetic neoplasia that causes increased RBC production
polycythemia vera
27
tumor of blood
neoplasia
28
hematocrit is approx equal to what
PCV (packed cell volume)
| +/- buffy coat, depending on source
29
What does the buffy coat consist of?
WBCs and platelets (~1-2%)
30
drop of blood smeared, air dried, stained with modified Romanovsky method
blood smear
31
Blood smear examples
Wright
Giemsa
Diff-Quick
32
What are blood smears stained with?
modified Romanovsky method
33
process by which mature blood cells develop from precursor cells
hemopoiesis
34
RBC production
erythropoiesis
35
WBC production
myelopoiesis
36
What is hemopoiesis under control of?
erythropoietin
37
What is erythropoietin secreted by?
kidney
38
What does hemopoiesis begin with?
pluripotent stem cell
39
What does a pluripotent stem cell differentiate into?
several unipotential stem cell lines (colony forming units = CFUs)
40
Where does hemopoiesis occur in adult humans?
vascular sinuses of bone marrow of cert bones—especially flat bones of skull, ribs, sternum, vertebrae, pelvis, & some long bones
41
What is the estimated output of hemopoiesis daily?
2.5 billion (short-lived)
42
Where does hemopoiesis occur in the fetus during the first trimester?
blood islands in the wall of yolk sac
43
What is the yolk sac rich in and what is the benefit of it?
iron needed to produce hemoglobin
44
Where does hemopoiesis occur in the fetus during the second trimester?
liver and lymphatic tissue
45
Where does hemopoiesis occur in the fetus during the last month of pregnancy?
bone marrow
46
Where does hemopoiesis occur at the time of birth?
primary to marrow cavities
47
Do the number of active sites in hemopoiesis increase/decrease with age?
increase
48
What are the 2 types of bone marrow?
red and yellow
49
Type of marrow that contains large numbers of mature RBCs and large nuclei:
red
50
Type of marrow that is inactive and known as "fatty" marrow
yellow
51
What are the stages of erythropoiesis?
stem cell (CFU-E) --> proerythroblast --> erythroblast/normoblast --> reticulocyte --> mature RBC
52
Overall trends in erythropoiesis:
(increase/decrease) in cell size
(loss/gain) of nucleus and organelles
(increase/decrease) in hemoglobin concentration (Hb)
decrease
loss
increase
53
RBCs (erythrocytes) enucleate where?
mammals ONLY
54
type of nucleus in RBC in mammals:
enucleate
55
What happens to the nucleus in erythrocytes before it is release into the bloodstream?
nucleus extruded and all organelles degenerate
56
What do mature RBCs consist of?
outer cell membrane containing cytoplasm, Hb, and few enzymes
57
T/F: RBCs have a mitochondria.
false: lack mitochondria
58
What effect does a lack of mitochondria have on RBCs.?
limited lifespan (~120 days)
59
If RBCs lack mitochondria, how can they make ATP?
anaerobic glycolysis (enough to maintain cell integrity)
60
Which organs remove senescent (old) RBCs?
liver and spleen
61
occasional, basophilic nuclear remnants visible within cytoplasm during erythropoiesis
Howell-Jolly bodies
62
immature RBCs with stippled cytoplasm and still have some rRNA, but slightly larger than mature RBCs (erythropoiesis)
reticulocytes
63
increased reticulocytes in circulation associated with chronic blood loss, hemolytic anemia— aka "left shift"
reticulocytosis
64
What leads to large cells called macrocytes?
vit B12 and B9 deficiency
65
large numbers of erythrocyte precursors in peripheral blood
megaloblastic anemia
66
****What is the size of RBCs?
6-8 um (micrometer) diameter
67
What is the concavity of RBCs?
biconcave discs
68
What is the primary structural protein in RBCs?
spectrin
69
What is the function of spectrin in RBCs?
provides resiliency and deformability
70
Where does spectrin bind?
inner surface of PM
71
What is the purpose of the biconcave shape of erythrocytes?
increase surface area for gas exchange
72
which cells are involved in O2 and CO2 transport
rbcs (erythrocytes)
73
which cells contain large amount of Fe containing pigment, hemoglobin
rbcs (erythrocytes)
74
Fe containing pigment
hemoglobin
75
what do RBCs transport?
o2 and co2
76
What makes up Hb?
4 polypeptide chains associated with 4 Fe-containing heme groups
77
decreased Fe or blood loss
anemia
78
type of anemia where rbc’s are small (microcytic) & pale staining (hypochromic)
Fe deficient anemia
| vs. normocytic and normochromic
79
single AA substitution that causes a change in 3D structure of Hb molecule
sickle cell anemia
80
What is the AA substitution in sickle cell anemia?
valine for glutamic acid at position 6 of beta-globulin chain
81
sickle cell anemia causes a _____ change in cell which leads to "_____" shape; more ___ and easily _____.
conformational
sickle
fragile
damaged
82
What do sickle-shaped RBCs damage?
endothelial cells of capillary walls due to rough edges
83
What is a potential benefit to sickle cell anemia?
resistance to malaria
84
disease caused by an intracellular parasite, Plasmodium spp.
malaria
85
thrombocytes =
platelets
86
small, non-nucleated cells containing organelles
platelets
87
Do platelets have nuceli?
no
88
Do platelets have organelles?
yes
89
What are platelets formed from?
megakaryocytes
90
large, polyploid cells in bone marrow with single, multi-lobed nucleus
megakaryocytes
91
megakaryocytes develop _____ channels in the _____ which causes platelets to do what?
demarcation
cytoplasm
tear off
92
What is the function of platelets?
blood clotting - form vascular plugs at site of vascular damage
93
What can impair platelet function?
drugs like aspirin
94
Result of cascade interaction between plasma proteins & coagulation factors
coagulation
95
When does coagulation occur?
only if endothelial lining of vessel is injured
96
What are the 2 pathways fo coagulation?
intrinsic
| extrinsic
97
Which coagulation pathway is faster?
extrinsic
98
The extrinsic coagulation pathway is initiated by what?
release of tissue thromboplastin as result of tissue damage
99
The intrinsic coagulation pathway is initiated by what?
exposure of collagen
100
What does the intrinsic coagulation pathway require?
numerous clotting factors (Willebrand's factor, Factor VIII) and longer cascade reaction
101
Describe the steps of coagulation
1. When wall of blood vessel breaks, tissue injury results
2. Releases thromboplastin, initiates extrinsic pathway —Also exposes collagen, initiates intrinsic pathway
3. Platelets mechanically adhere to exposed collagen; also release serotonin (potent vasoconstrictor—constricts sm Mm in damaged vessel to minimize blood loss)
102
Extrinsic & intrinsic pathways converge to form ____ pathway (at point where ______ activated)
common
| Factor X
103
Converging of extrinsic and intrinsic pathways results in what?
conversion of prothrombin to thrombin, converts soluble fibrinogenin to insoluble fibrin
104
What does coagulation trap?
platelets and RBCs
105
What stops clotting?
- Exhaustion of fibrinogen and removal of thrombin from blood during conversion of fibrinogen to fibrin
- anticoagulants: antithrombin III & heparin
106
Inappropriate clot formation leads to what?
heart attack, stroke, DIC
107
Deficiency in clotting factor(s), so blood can’t clot; defect in intrinsic pathway
hemophiia
108
Hemophilia is ___-linked and found in (males/females)
sex
| males
109
Which chromosome is hemophilia present on?
X chromosome
110
deficiency of clotting Factor VIII
Hemophilia A
111
Factor IX deficiency
Hemophilia B
112
Factor XI deficiency
Hemophilia C
