Erythrocytes Flashcards
(3-4) Functions of Blood:
–Transportation or exchange
–Protection (immunity)
–Regulation (fluid volume, pH,
thermoregulation)
–Constituents of blood (cells,
proteins and serum) must
contribute to one or more of
these functions
Blood: Considered a ___ because it
contains cells, a liquid ground substance (called
plasma), and dissolved protein (fibers).
connective tissue
Blood is about ____ times more viscous than water.
About four (a lot thicker/stickier)
2 compartments blood can be broken down into:
liquid and cellular
components.
Average volume of blood in adults ~
5 liters
3 main components of blood:
Erythrocytes, buffy coat, plasma
typically make up about
44% of a blood sample
Erythrocytes
measurement of %RBC volume
a blood test that measures the percentage of red blood cells in your blood
hematocrit
composed of leukocytes (or
white blood cells) and cell
fragments called platelets
* forms less than 1% of a
blood sample
buffy coat
Formed element making up largest % of blood? What is least?
most: erythrocytes (99%)
least: leukocytes (less than 0.1%)
Fluid component of blood, minus the
formed elements
* generally makes up about
55% of blood
Plasma
Formed Elements in blood:
Erythrocytes, Leukocytes, platelets (thrombocytes)
- primary function is to transport
respiratory gases in the blood
*make up more than 99% of
formed elements of
Erythrocytes
- contribute to defending the
body against pathogens
*make up less than .01% of
formed elements
Leukocytes
make up less than 1% of
formed elements and
* help with blood clotting
Platelets (Thrombocytes)
RBC> Platelets > WBC
drop of
blood smeared, air dried
& stained
Blood Smear:
The_____ is
examined for the # and
kind of cells present and
other morphological
abnormalities
blood smear
____: Complex mixture of water, proteins, and other solutes.
Plasma
When the proteins are moved from plasma, the remaining fluid is
termed ___
serum
___ makes up about 92% of plasma’s total volume.
* it facilitates the transport of materials in the plasma
Water
The next most abundant materials in plasma
are the _____
plasma proteins
(6 and 8 grams of protein in a volume of 100
milliliters of blood)
The plasma proteins include
Albumins
* Globulins
* Fibrinogen
* Regulatory proteins – primarily enzymes &
hormones
* Spectrin (cytoskeletal not plasma)
____ transports many small molecules in the blood
(bilirubin, calcium, progesterone, and drugs).
–Function as transport proteins for insoluable metabolites
Albumin
Albumin has prime importance in maintaining the ____
of the blood
oncotic pressure
(keeping the fluid from leaking out into the tissues).
T/F: The concentration of albumin in the blood is
much less than it is in the extracellular fluid.
False: The concentration of albumin in the blood is
much greater than it is in the extracellular fluid.
Because albumin is synthesized by the ___, decreased
serum albumin may result from ___ disease
liver
Decreased serum albumin can also result from ___ disease, which allows
albumin to escape into the urine.
kidney
Decreased albumin
may also be explained by malnutrition or a ____
diet.
low protein
Makes up about 4% of all plasma proteins.
–Also made in the liver.
–Responsible for blood clot formation
Fibrinogen
Following trauma to the walls of blood vessels,
fibrinogen is converted into long, insoluble strands
of ___, which is the essence of a blood clot
fibrin
Smaller alpha-
globulins and the
larger beta-globulins
primarily bind,
support, and protect
certain ____,
hormones, and ions
water-
insoluble or
hydrophobic
molecule
(act as carrier proteins!)
___ are
immunoglobulins or
antibodies
Gamma-globulins
___ is the main structural
component of the RBCs
Spectrin
____ was first identified in
erythrocytes, where it forms a
filamentous network required
for red blood cells to maintain
their shape and elasticity
Spectrin
need ___ to make RBCs look and function the way they should
Spectrin (bioconcave–donut)
Spectrin was first identified in
____, where it forms a
filamentous network required
for red blood cells to maintain
their shape and elasticity
erythrocytes
Spectrin Binds to inner surface of the
___
plasmalemma
In adult humans, Hemopoiesis occurs in ______ of certain
bones—especially flat bones of skull, ribs, sternum, vertebrae, pelvis, &
some long bone
vascular sinuses of bone marrow
In fetus, hemopoiesis first occurs in ____
during first trimester
“blood islands” in wall of yolk sac
–starts outside bc not enough fetal tissue in beginning
During second trimester, hemopoiesis occurs in liver & lymphatic tissue & during last
month of pregnancy in ___
bone marrow
At time of birth, hemopoiesis restricted primarily to ___
marrow cavities
hemopoiesis: # of active sites ___ with age
↓ decreased
(make fewer as get older–fewer RBC and WBC)
Process by which mature
blood cells develop from
precursor cells (myeloid stem cell)
Hemopoiesis
—red cell
production
Erythropoiesis
—white
cell production
Myelopoiesis
Hemopoiesis: Under control of
___, secreted by
kidney
erythropoietin
(can be introduced endrogenously–lance armstrong)
erythropoietin is secreted by the
kidney
Hemopoiesis: Begins with pluripotential
stem cell which
differentiates into several
____ stem cell
lines
[= colony forming units
(CFU’s)]
unipotential
__ marrow: active,
contains large #’s of
mature rbc’s
Red
Inactive Marrow
Yellow or Fatty Marrow
Erythropoiesis Stages:
Stem cell (CFU-E) ➔
proerythroblast ➔
Basophilic erythroblast➔ polychromatic erythroblast ➔ orthochromatic erythroblast➔
reticulocyte ➔ mature
rbc
Erythropoiesis Stages: Basic primative cell
proerythroblast
Erythropoiesis–Overall trends:
cell size, loss of
nucleus &
organelles, ↑ in
[Hb]
(cytoplasm gets more eosinophilically stained–redder)
First recognizable erythrocyte precursor
Proerythroblast(/early
Normoblast)
Proerythroblast: the cell is large with fine, granular nuclear
chromatin containing one or more paler nucleoli. The relatively sparse cytoplasm is
strongly basophilic due to its high content of ___ and ___
RNA and ribosomes.
Proerthroblast/Early Normoblast: A narrow, pale
zone of cytoplasm close to the nucleus represents the ____
Golgi apparatus
Proerythroblasts divide and differentiate, producing smaller cells called ____
basophilic
erythroblasts or early normoblasts
These are smaller cells with some condensation
and clumping of chromatin.
basophilic
erythroblasts or early normoblasts
Polychromatic erythroblasts
(intermediate normoblast): In these cells the cytoplasm develops a grey coloration due to
increasing cytoplasmic _____
hemoglobin
a mixture of basophilia and
eosinophilia–
polychromasia
The nuclear chromatin becomes
increasingly condensed. These cells are no longer capable of division
Polychromatic erythroblasts
Orthochromatic erythroblast
(late normoblast): The
cytoplasm is rich in _____ but still contains ribosomes with continuing
hemoglobin synthesis.
hemoglobin
The final nucleated form
orthochromatic erythroblast (late normoblast).
orthochromatic erythroblast (late normoblast): Cytoplasmic organelles are ____. The nuclear
chromatin, and nucleus, becomes extremely condensed; the nucleus is then
extruded.
degenerate
orthochromatic erythroblast (late normoblast): The nuclear
chromatin, and nucleus, becomes extremely condensed; the nucleus is then
extruded. The result is an ___ early red cell, the reticulocyte
anucleate
The nuclear
chromatin, and nucleus, becomes extremely condensed; the nucleus is then
extruded. The result is an anucleate early red cell, the ____
reticulocyte
occasional,
basophilic nuclear remnants visible
within cytoplasm, Usually removed
by the spleen
Howell-Jolly bodies
immature
rbc’s with stippled cytoplasm;
still have some rRNA
Slightly larger than mature rbc’s
Reticulocytes
Mature erythrocytes lack___ (circulate ~120 days)
nuclei & organelles
RBCs are replaced in the circulation by ____, which complete
their hemoglobin synthesis and maturation 1 to 2 days after entering the
circulation.
reticulocytes
___ account for 1% to 2% of circulating RBCs
Reticulocytes
RBCs can only make ATP by ____ glycolysis
anaerobic
(don’t have mitochondria)
Erythrocytes: How does their lack of nuclei affect function?
carry respiratory gases
(ex: more efficient at carrying oxygen)
Every erythrocyte is filled with
approximately 280 million
molecules of __
hemoglobin
Each ___ molecule
consists of four protein
globins.
hemoglobin
All globin chains contain a
____ group
that is in the shape of a ring,
with an iron (Fe) ion in its
center
nonprotein (or heme)
All globin chains contain a
nonprotein (or heme) group
that is in the shape of a ring,
with an ____ ion in its
center
iron (Fe)
Oxygen binds to _____
for transport in the blood.
iron ions
Each hemoglobin molecule
consists of four protein
globins.–
Alpha (α) chains and beta (β)
chains
any condition in
which the quantity of
erythrocytes is lower than
normal
anemia
Inadequate production
of/survival of RBCs
anemia
Lethargy, shortness of
breath, pallor, fatigue, heart
palpitations are common symtoms of
anemia
Anemia is a ____ disorder
Erythrocyte volume disorder
How is heart rate affected by Anemia?
Increased–has to work harder to supply tissues
Polycythemia: blood becomes ___
thick and viscous
(have too many erythrocytes in the blood)
condition of having too
many erythrocytes in
the blood
Polycythemia
–
RBC growth in the red
marrow not regulated
Polycythemia vera
(blood is thick and sticky–blood has to work harder to push out)
Polycythemia is a ___ disorder
Erythrocyte volume disorder
from a point mutation in which
glutamic acid is replaced by valine at the sixth position in the β-
globin chain.
Sickle Cell Anemia
Sickle Cell Anemia is a ___ abnormality
hemoglobin
Defective hemoglobin (Hb S) tetramers aggregate and
polymerize in deoxygenated RBCs, changing the ____ shape into a rigid and less deformable ____ shape
biconcave
disk –> sickle-shaped cell.
Hb S (defective hemoglobin) leads to severe chronic hemolytic anemia and obstruction
of _____
postcapillary venules
Sickle Cell Anemia causes ___ in cell => “sickle”
shape; more fragile, easily
damaged
conformational
change
Sickle-shaped rbc’s also cause
damage to endothelial cells
of capillary walls due to
___
rough edges
Sickle cell anemia confers
resistance to ___
malaria
Elliptocytosis is a ___ abnormality
Cytoskeletal abnormality (spectrin)
autosomal dominant disorder
characterized by the presence of oval-shaped RBCs
Elliptocytosis
Elliptocytosis is
caused by defective self-association of ____ subunits
& defective binding of ___
spectrin. spectrin.
Spherocytosis is a ___abnormality
cytoskeletal
____ is also an autosomal dominant condition
involving a deficiency in spectrin.
Spherocytosis
The common clinical
features of elliptocytosis and spherocytosis are anemia,
jaundice, and ____ (enlargement of the spleen).
splenomegaly
Splenectomy is usually curative, because the spleen is
the primary site responsible for the destruction of
_____
elliptocytes and spherocytes.
thrombocytes— ~___ mm in diameter
2-4
Small, non-nucleated cells containing
organelles
platelets
Platelets are formed from large, polyploid cells in
bone marrow, _____
–have single, multi-lobed nucleus
–up to 100mm in diameter
megakaryocytes
Cells develop pleated _____ in cytoplasm—platelets “tear
of
demarcation
channels
Lifespan of human platelets
8-12 days
Platelet function in blood clotting—
form
physical plugs at site of vascular
damage
Can drugs impair platelet function?
Yes –aspirin
Result of cascade interaction between plasma
proteins & coagulation factors
coagulation
coagulation: Occurs only if ____ of vessel injured
endothelial lining
2 convergent pathways of coagulation:
extrinsic and intrinsic
Extrinsic pathway: faster—
Initiated by release of ____ as a result of tissue
damage
tissue thromboplastin
Intrinsic pathway slower—initiated by exposure of ____
collagen
Which coagulation pathway requires numerous clotting factors (e.g., von Willebrand’s factor, Factor
VIII) & longer cascade rxn
Intrinsic Pathway (slower)
When wall of blood vessel breaks,
___ injury results
tissue
When wall of blood vessel breaks,
tissue injury results, releasing ____ which initiates the extrinsic pathway
thromboplastin
Coagulation: Platelets mechanically adhere to
exposed collagen; also release
________
(potent
vasoconstrictor—constricts smooth
muscle in damaged vessel to
minimize blood loss)
serotonin
potent
vasoconstrictor—constricts smooth
muscle in damaged vessel to
minimize blood loss
serotonin
Extrinsic & intrinsic pathways converge to form ___
pathway (at point where Factor X activated)
common
Extrinsic & intrinsic pathways converge to form common
pathway (at point where Factor X activated)
–Results in conversion of ___ to thrombin, converts
soluble fibrinogen into insoluble fibrin
prothrombin
Traps platelets & rbc’s
insoluble fibrin
What stops clotting?
–Exhaustion of fibrinogen & removal of ___ from blood
during conversion of fibrinogen to fibrin
thrombin
2 anticoagulants that stop clotting:
antithrombin III & heparin
Inappropriate __ formation => heart attack, stroke
clot
Deficiency in clotting factor(s), so blood can’t clot; defect in intrinsic
pathway
–Sex-linked, in males; present on X chromosome
Hemophilia
—deficiency of clotting Factor
VIII
Hemophilia A
—Factor IX deficiency
*Hemophilia B
—Factor XI deficiency
*Hemophilia C
Von Willebrand’s disease: Factor 8 (FVIII)
and von Willebrand factor (VWF) are two distinct
but related _______ that circulate in plasma
as a tightly bound complex (FVIII/VWF).
glycoproteins
Hemophilia is a defect in the ____ pathway
intrinsic
