Blood-Histology

Front 1

Justify blood as a connective tissue.

Back 1

--

Front 2

Formed Elements of blood

Back 2

Consists of cells (white blood cells, red blood cells)
and cell fragments (platelets).

Front 3

Liquid Intercellular Material (plasma)

Back 3

serum +
clotting proteins.

Front 4

If coagulation is prevented by a chemical additive (e.g.: citrate, heparin)
and the blood is centrifuged, a layering will be observed. What will we see

Back 4

Upper 54% Plasma (serum + clotting elements)
Middle 1% WBC’s + Platelets (“Buffy Coat”)
Lower 45% RBC’s
Hematocrit is defined as the volume of RBC’s

Front 5

The fluids in the interstitial compartment are derived by

Back 5

filtration from
the blood compartment due to the HYDROSTATIC PRESSURE OF
BLOOD.

Front 6

Erythrocytes, or red blood cells (RBC’s)
How many? Are they nucleated when mature

Back 6

are anucleated cells when mature and
number approximately 5 million/mm3.

Front 7

The RBC’s measure approximately ____ in diameter.

Back 7

7.5 µm

Front 8

Erythrocytes, or red blood cells (RBC’s)contain ______ which contains ______

Back 8

hemoglobin, Fe++

Front 9

Each heme group contains iron Fe++ and is capable of combining with O2 to form

Back 9

oxyhemoglobin

Front 10

Each heme group contains iron Fe++ and is capable of combining with CO2 to form

Back 10

carbaminohemoglobin

Front 11

Each heme group contains iron Fe++ and is capable of combining with CO to form

Back 11

carboxyhemoglobin

Front 12

Erythrocytes have the shape of biconcave disks which allows a greater surface area for what gas exchange

Back 12

O2 <-> CO2.

Front 13

Energy is expended to maintain erythrocyes shape and requires _____ made through ________

Back 13

ATP

anaeobic glycolysis (also pentose phosphate
pathway).

Front 14

Cells placed in a hypertonic solution lose water and undergo a structural change called _________.

Back 14

crenation

Front 15

When cells are placed in a ___________ solution, hemolysis occurs, a process whereby hemoglobin dissolves out of the cells leaving an
“empty” shell or “ghost”.

Back 15

hypotonic

Front 16

Erythrocytes are produced in the ___________ as nucleated cells. They loose their nuclei before leaving the marrow.

Back 16

bone marrow

Front 17

They leave the bone marrow and circulate for about _______ days. After this
period, they undergo ________

Back 17

90-120/destruction

Front 18

Destruction of RBCs occurs mainly in the ______ by macrophages although
phagocytic cells in the bone marrow participate in this process.

Back 18

spleen

Front 19

Erythrocytes are engulfed and digested by lysosomal action. In the process,
hemoglobin is broken down into ____ and ____.

Back 19

heme / globin

Front 20

Heme is broken down into ________ and ________

Back 20

ferritin (iron-containing component)

bilirubin

Front 21

Globin is dissociated into what?

Back 21

its amino acid compoments which join the amino acid pool.

Front 22

Ferritin is sent where?

Back 22

to the marrow for reutilization

Front 23

Where does biliruben go?

Back 23

Bilirubin is picked up by the liver and excreted with the bile.

Front 24

Leukocytes or white blood cells (WBC’s). How many

Back 24

approximately 4-10 thousand/mm3.

Front 25

Leukocytes or white blood cells (WBC’s) Are they nucleated when mature?

Back 25

are nucleated cells when mature

Front 26

In general, WBCs are involved in what?

Back 26

the cellular and humoral defense of the organism
against foreign material.

Front 27

The main functions of the WBCs is performed Where?

Back 27

in the connective tissue

Front 28

The cells
leave the vascular spaces by a process of _________.

Back 28

diapedesis

Front 29

Granulocytes are so-called because

Back 29

they contain “specific” granules peculiar to
that cell type.

Front 30

What are the three types of granulocytes:

Back 30

Neutrophils, Eosinophils, & Basophils.

Front 31

Azurophilic (primary, non-specific) granules

Why primary. Why non-speceific?

Back 31

rich in acid phosphatase
and peroxidase.

when stained with Wright’s stain, they have an azure hue

also called primary because in the development of the cell,
they are the first type of granule to appear.

The “non-specific”
term is applied since these granules are found in all three cell types and are not “specific” to one type of cell.

Front 32

Neutrophils respond to ________ which results in their migration to the sites containing the microbes.

Back 32

chemotactic agents

Front 33

Once Neutrophils phagocytose the bacteria, they destroy them through the actions of the _______ in the ________.

Back 33

hydrolytic ezymes / azurophilic granules

Front 34

_________ and ________also serve to attract other neutrophils to the area.

Back 34

hydrolytic ezymes / azurophilic granules

Front 35

Neutrophils synthesize ________ which aid the initiation of the inflammatory process.

Back 35

leukotrienes

Front 36

Neutrophils die in the process of killing the bacteria. The accumulation of tissue fluid, dead neutrophils and bacteria is referred to as ____.

Back 36

pus

Front 37

__________ are developed after the primary granules and contain substances
peculiar to a specific cell type (neutrophils, eosinophils, basophils).

Back 37

Specific (secondary) granules

Front 38

The granulocytes are named according to the
staining characteristics of their ____________.

Back 38

secondary granules

Front 39

Neutrophils comprise approximately ______ of the circulating leukocytes.

Back 39

60-70%

Front 40

Neutrophils main function is to destroy ________.

Back 40

invading microbes

Front 41

A mature neutrophil measures about _______ in diameter

Back 41

12-15µm

Front 42

The nucleus
contains ______ lobes, each interconnected by fine strands of chromatin.

Back 42

2-5

Front 43

The ________ granules of the neutrophils are typical lysosomes containing
acid hydrolases, myeloperoxidase, cathepsin G, collagenase,
and elastase.

Back 43

azurophilic

Front 44

The ________ granules contain various enzymes and other agents that aid
the neutrophils in performing its antimicrobial functions. These include
such agents as alkaline phosphatase, lysozyme, and collagenase

Back 44

specific

Front 45

Neutrophils
derive their name from the fact that their secondary granules appear
NOT to stain in Wright’s stain. Close observation, however, demonstrates
_____________.

Back 45

a very light lavender hue

Front 46

The azurophilic granules of the basophils are ___________

Back 46

typical lysosomes containing acid hydrolases.

Front 47

The _________ of basophils contain histamine, leukotrienes, (SRS), heparin, eosinophil chemotacticfactor, and neutrophil chemotactic factor. These cells are functionally related to but not identical with mast cells.

Back 47

specific granules

Front 48

The _________ and __________ released by basophils play a role in the dilation of small blood vessels and in the increase in permeability of capillaries.

Back 48

histamine / leukotrienes (SRS)

Front 49

As is the case with mast cells, the basophils bind _____(an antibody secreted by plasma cells)onto its surface following an initial exposure to an allergen. Upon subsequent exposure, the
allergen binds to the ____ and ruptures the cell membrane bringing about a release of the vasoactive
substances.

Back 49

IgE

Front 50

Eosinophils comprise approximately ______ of the circulating
leukocytes.

Back 50

1-3%

Front 51

main fx of eosinophils

Back 51

destroy parasites (e.g.
worms) and hydrolyze antigen-antibody complexes.

Front 52

A mature eosinophil measures about ______ in diameter

Back 52

12-15µm

Front 53

The nucleus of an contains ___ lobes, each interconnected by fine strands of chromatin.

Back 53

2

Front 54

The azurophilic granules of the eosinophils are ________ containing ____________
similar to neutrophils. These enzymes are involved in hydrolyzing phagocytosed antigen-antibody
complexes.

Back 54

typical lysosomes / acid hydrolases

Front 55

The specific granules of eosinophils are refractile under the light microscope and stain ______ in Wright’s stain.

Back 55

pink

Front 56

These granules are uniform in size. They contain aryl sulfatase (to neutralize SRS), histaminase
(to neutralize histamine), major basic protein and eosinophil cationic protein; the latter
two are secreted onto the surface of ___________ thereby killing them.

Back 56

parasitic worms

Front 57

Basophils comprise approximately _____ of the circulating leukocytes.

Back 57

0.5-1%

Front 58

A mature basophil measures about _____ in diameter.

Back 58

12-15µm

Front 59

The nucleus of the basophil is usually _______ but may be obscured by the dark specific granules.

Back 59

lobulated

Front 60

Some of the circulating lymphocytes are slightly larger at 10-12 µm and are called __________.

Back 60

medium
lymphocytes

Front 61

Agranulocytes include _______ and ________.

Back 61

lymphocytes / monocytes

Front 62

Agranulocytes do not have “specific” granules, however, they do contain variable numbers of __________.

Back 62

azurophilic granules (lysosomes)

Front 63

About ____ of the circulating leukocytes consist of lymphocytes.

Back 63

30%

Front 64

Most of the lymphocytes measure about _____ or slightly larger than erythrocytes. These cells are classified as small lymphocytes.
The ________ almost fills the entire cell.

Back 64

8-10 µm
/nucleus

Front 65

About _____ of the circulating leukocytes consist of monocytes.

Back 65

3-8%

Front 66

MONOCYTES are quite large cells, measuring approximately ______ .

Back 66

20-30µm

Front 67

The large nucleus of the MONOCYTE is frequently _______ and has chromatin that is not
as dense as the other leukocytes.

Back 67

indented

Front 68

After entering the connective tissue spaces, monocytes transform into _______ and become active phagocytes.

Back 68

macrophages

Front 69

As would be expected, The cytoplasm of contains lots monocytes of ___________.

Back 69

lysosomes (azurophilic granules).

Front 70

FUNCTIONS of monocytes

Back 70

1. Phagocytosis of debris, antigenic material, and foreign matter such as bacteria.
2. Macrophages fuse with other macrophages to form foreign body giant cells
to allow phagocytosis of large material.
3. They secrete cytokines that activate the inflammatory process.

Front 71

Platelets are cell fragments (2-4 µm) that bud off of very large
cells (ca. 150µm), called __________ that are located in the ________.

Back 71

megakaryocytes

bone marrow

Front 72

They number about 250, 000-400,000/mm3 and have a life
span of about ____ days.

Back 72

14

Front 73

Numerous granules are present in the cytoplasm of platelets and contain a variety of substances such as: give 3

Back 73

platelet growth-factor
platelet thromboplastin
thrombospondin
coagulation factors
ADP
ATP
seratonin
histamine
hydrolytic enzymes

Front 74

Platelet functions are related to _________ .

Back 74

hemostasis

Front 75

Following damage to a blood vessel, the platelets become activated upon contacting the
_____________ and release the contents of their granules. As a result, the platelets adhere to the damage site.

Back 75

subendothelial collagen

Front 76

_________ causes the platelets to become
“sticky” and adhere to each other. This process results in a “plug” being formed thereby reducing blood loss.

Back 76

thrombospondin

Front 77

__________ released from platelets, causes vasoconstriction which further helps to reduce blood loss

Back 77

Seratonin

Front 78

_____ _______ is a specialized, highly cellular connective tissue located in the cavitations of the bones.

Back 78

Bone marrow

Front 79

Bone marror originates in the ______ month of intrauterine life within the clavicles (1st bones
to ossify) and expands with maturation of the remaining bones.

Back 79

second

Front 80

In the ______ month it is found in within the scapulae, innominate bones, occipital bones, ribs, & vertebrae.

Back 80

third

Front 81

When it first appears, the marrow is concerned primarily with the _________ of bones. It maintains this _________ function throughout life.

Back 81

growth and
remodeling

osteogenic

Front 82

Functions of Bone Marrow

Back 82

1. Hematopoiesis

2. Hematoclasia

3. Immunological

4. Osseous

Front 83

Hematopoiesis fx in bone marrow

Back 83

Marrow functions in the production of all erythrocytes, granulocytes, platelets,
monocytes, and a small portion of lymphocytes.

Front 84

Hematoclasia fx in bone marrow

Back 84

Specialized cells resident in the marrow participate in the destruction of imperfect,
aged, and damaged cells.

Front 85

Immunological fx in bone marrow

Back 85

Supplies stem lymphocytes to their respective lymphoid organs. Monocytes
originate from the marrow and later differentiate into macrophages, a cell type
that is important in the initial processesing of antigens and the phagocytosis
and destruction of foreign material.

Front 86

Osseous fx in bone marrow

Back 86

Marrow contains osteoblasts and osteoclasts that function in the continual
remodeling of bone.

Front 87

Marrow is classified as _____ or ______.

Back 87

red / yellow

Front 88

_______ is red in color and indicates active hematopoiesis.

Back 88

Red marrow

Front 89

In adults, red marrow
is found in the ____ bones of the body.

Back 89

flat

Front 90

__________ is so-called due to large populations of fat cells. There is very
little hematopoiesis in this type of marrow.

Back 90

Yellow marrow

Front 91

In neonates, the marrow in all the bones is ____.

Back 91

red

Front 92

Fat appears in the shafts of long bones about ____ years of age.

Back 92

5-7

Front 93

By the 18th year, almost all the marrow in the long bones is _____.

Back 93

yellow

Front 94

Marrow is subdivided into what two main “compartments”:

Back 94

1. Vascular compartment
2. Hemopoietic compartment

Front 95

Nutrient arteries enter bone via nutrient foramina and branch into smaller
vessels. These smaller vessels empty into an extensive network of
sinusoids that is found throughout the marrow cavity. Blood from the
sinusoids drain into veins that leave through the nutrient foramina.
Sinusoids are the predominate vascular element in the marrow and measure
between 50-75µm in diameter. They are comprised of a single layer of
endothelial cells with a thin basement membrane and are surrounded by
reticular fibers and phagocytic cells.
The walls of the sinusoids are frequently and
regularly crossed by cells in transit.
What compartment does this describe?

Back 95

Vascular compartment

Front 96

Megakaryocytes are located predominately against the outer walls of the _______
to provide ready access of platelets to the circulation.

Back 96

sinusoids

Front 97

Located between the sinusoids and contains:
1) the cells of the hemopoietic lineage.
2) connective tissue cells such as mast cells, macrophages, plasma cells,
and reticular cells.
What compartment is this?

Back 97

Hemopoetic

Front 98

Erythrocytes in early development are located ____ the sinusoids and in late
development are located ___________ sinusoids.

Back 98

near / against the walls of the

Front 99

Granulocytes in early development are located _________ sinusoids and
in late development are located ___________ sinusoids.

Back 99

the furthest from the / against the walls of the

Front 100

The earliest stages of hemopoiesis, the __________, occurs in the yolk sac at about 2 weeks after fertilization.

Back 100

mesoblastic phase

Front 101

During the mesoblastic phase, Mesenchymal cells form ________ ; the outer cells develop into vessel walls and the inner cells develop into nucleated erythrocytes.

Back 101

blood islands

Front 102

The _________ begins about the sixth week of gestation. Initially, only
erythrocytes are produced. At about 8 weeks, leukocytes are produced.

Back 102

hepatic phase

Front 103

The ___________ during the second trimester and continues with the
hepatic phase until the end of gestation.

Back 103

splenic phase

Front 104

myeloid phase

Back 104

the end of the second trimester.

Hemopoiesis begins in the bone marrow

Front 105

extramedullary hemopoiesis

Back 105

The liver and spleen are normally not involved in hemopoiesis
after birth, however, in times of need, they can become active in this process

Front 106

About 0.1% of the cells in the marrow are _____________ that give rise to all the cell types of the blood cell lineage.

Back 106

Pleuripotential Hemopoietic
Stem Cells (PHSC’s)

Front 107

The PHSC’s give rise to two lineages. What are they?

Back 107

CFU-S (CFU-GEMM) (colony forming unit-spleen)
and CFU-L (colony forming unit-lymphocyte).

Front 108

The CFU-S (CFU-GEMM) gives rise to stem cells that will differentiate into:

Back 108

erythrocytes
granuloctes
monocytes
megakaryocytes

Front 109

The CFU-L gives rise to stem cells that will differentiate in
to:

Back 109

lymphocytes (T- and B- cells)

Front 110

In studying the development of the blood cells certain maturational
characteristics are observed:

What are they?

Back 110

a. Cell Size
-stem cells larger than mature cells

b. Cytoplasmic Color
The cytoplasm of the cells in early development tends to have a blue
cytoplasm owing to the large numbers of ribosomes present. The
cytoplasm is less basophilic as development ensues.

c. Chromatin Pattern
The chromatin is finely dispersed in the early stages but becomes “clumped”
in the later stages due to increased heterochromatin.

d. Nucleoli
Nucleoli are present in the earliest stages and are absent as development
proceeds.

e. Nuclear Morphology
The nuclei of developing erythrocytes are large with fine chromatin. As
development proceeds, the chromatin becomes very dense (pycnotic) and
is eventually extruded.
The nuclei of developing granulocytes are somewhat rounded that becomes
lobulated in the later stages of development.

Front 111

stages of Erythropoiesis

Back 111

a. Proerythroblast
b. Basophilic erythroblast
c. Polychromatophilic erythroblast

Front 112

Proerythroblast

Back 112

The proerythroblast is the first recognizable stage of the erythrocyte lineage.
It is a large cell measuring about 14-17 µm in diameter.
The nucleus is large, spherical, and centrally located. It may occupy up to
80% of the cell. The chromatin is fine.
One to two nucleoli are present.
The cytoplasm is basophilic due to lots of ribosomes.
THE PROERYTHROBLASTS UNDERGO MITOSIS to give rise to more proerythroblasts,
some of which develop into basophilic erythroblasts.

Front 113

Basophilic erythroblast

Back 113

The basophilic erythroblast is a smaller cell, measuring about 13-16 µm. The cytoplasm is strongly basophilic due to an increase in the number of
ribosomes which will be used largely for the synthesis of hemoglobin.
Condensation of the chromatin is apparent.
Nucleoli are absent.
BASOPHILIC ERYTHROBLASTS UNDERGO MITOSES to yield more basophilic
erythroblasts, some of which develop into polychromatophilic erythroblasts.

Front 114

Polychromatophilic erythroblast

Back 114

The polychromatophilic erythroblast measures about 12-15µm in diameter.
There is an obvious change in the nulear:cytoplasmic ratio.
The chromatin is more condensed than previous stages.
The cytoplasm is greyish in color due to the production of hemoglobin and
a reduction in the number of ribosomes.
POLYCHROMATOPHILIC ERYTHROBLASTS UNDERGO MITOSIS to yield more
polychromatophilic erythroblasts, some of which develop into orthochromatophilic
erythroblasts.
NOTE: This the LAST stage to undergo mitosis.

Front 115

Orthochromatophilic erythroblast (normoblast)

Back 115

The orthochromatophilic erythroblast measures about 8-10 µm in diameter.
The cytoplasm is pink, nearing that in color of a mature erythrocyte.
The pycnotic nucleus is centrally located in the early stages, but eventually
assumes an eccentric position and is then extruded.
Once the nucleus is extruded, the cell is called a RETICULOCYTE. Reticulocytes
are usually the first of this lineage to enter the circulation.

Front 116

Reticulocyte

Back 116

The reticulocyte is is slightly larger than a mature erythrocyte measuring
about 8-9 µm in diameter.
This stage is usually the first of this lineage that is put into circulation.
There is no central “halo” as there is in a mature erythrocyte since this cell
has not yet assumed a biconcave shape.
The reticulocyte has some cytoplasmic RNA which may be detected using
special RNA stains.
This cell circulates for about 24 hours during which it loses the rest of the
RNA and assumes a biconcave shape. It is then known as an erythrocyte.

Front 117

Erythrocyte

Back 117

During the first 24 hours in circulation, the reticulocyte assumes a biconcave shape.

Front 118

Stages of Granulocytopoiesis

Back 118

a. Myeloblast
b. Promyelocyte
c. Myelocyte (neutrophilic, eosinophilic, basophilic)
d. Metamyelocyte
e. Band (stab) cells
f. Mature granulocytes

Front 119

Myeloblast

Back 119

The myeloblast is the first recognizable stage of the granulocyte lineage.
One is UNABLE to discern which of the three types of granulocytes a particular myeloblast will development into.
It is a large cell measuring about 12-14 µm in diameter.
The nucleus is somewhat spherical and not necessarily centrally located. It does not occupy as much of the cell as found in the proerythroblast. The
chromatin pattern is fine.
One to three nucleoli are present. The cytoplasm is basophilic due to the presence of ribosomes.
MYELOBLASTS UNDERGO MITOSIS and give rise to more myeloblasts, some
of which will differentiate into promyelocytes.

Front 120

Promyelocyte

Back 120

Promyelocytes are somewhat larger than myeloblasts, measuring about 16-21 µm.
The hallmark of this stage is the presence of azurophilic granules (lysosomes). The chromatin pattern is fine. One to three nucleoli are present.
The cytoplasm is basophilic due to the presence of ribosomes. Promyelocytes UNDERGO MITOSIS and give rise to more promyelocytes
some of which will differentiate into myelocytes.

Front 121

Myelocyte (neutrophilic, eosinophilic, basophilic)

Back 121

The myelocytes measure about 12 µm in diameter.
The hallmark of this stage is the production of specific granules. It is at this
stage that the specific type of granulocyte can be identified.
The cytoplasm appears pale due to the presence of neutrophilic (specific)
granules that tend to mask the azurophilic granules.
The chromatin pattern is coarse.
Nucleoli are absent.
Myelocytes UNDERGO MITOSIS and give rise to more myelocytes some of
which will differentiate into metamyelocytes.
NOTE: This is the LAST stage to UNDERGO MITOSIS.

Front 122

Metamyelocyte

Back 122

THIS AND SUBSEQUENT STAGES ARE IDENTIFIED ON THE BASIS OF NUCLEAR MORPHOLOGY. Metamyelocytes measure about 12 µm in diameter.
The nucleus is elongate and has an indentation on one side that is less than 50%.
The chromatin pattern is coarse.

Front 123

Band (stab) cells

Back 123

Band cells have elongated nuclei that assume the shape of a horseshoe.

Front 124

Mature granulocytes

Back 124

Following the band stage, the nucleus becomes segmented. These cells will
develop 2-4 lobes per cell, each being interconnected by thin strands of
chromatin.

Front 125

There are two “structural compartments” where neutrophils are located:
What are they?

Back 125

bone marrow &
blood vessels.

Front 126

Within the two structural compartments where neutrophils are located there, are four “functional compartments”:

Back 126

1. Medullary formation
2. Medullary reserve
3. Circulating pool
4. Marginal pool

Front 127

The ___________ consists of cells that are in some stage of development (mitotic & maturation pools). These include myeloblasts through the band stage.

Back 127

medullary formation compartment

Front 128

The __________ contains those cells that are fully- or almost fully developed and are waiting for a “signal” to enter the circulation. These include band and segmented cells. While it is the segmented cells that are normally put into circulation, it is
not uncommon for band cells to enter this pool, especially in cases of infections where
there is increased demand for neutrophils.

Back 128

Medullary reserve compartment

Front 129

Neutrophils enter the __________ and circulate for a few days. They then begin
the exit from the vascular system by first adhering to the inner wall of the vessel
(AKA ________). Then, by the process of diapedesis, they enter the connective tissues.

Back 129

circulating pool
/
marginal pool

Front 130

Conditions that lead to detachment include What?

Back 130

strenuous exercise, release of adrenaline, etc.

Front 131

Within the two structural compartments where neutrophils are located there, are four “functional compartments”:

Back 131

1. Medullary formation
2. Medullary reserve
3. Circulating pool
4. Marginal pool

Front 132

The ___________ consists of cells that are in some stage of development (mitotic & maturation pools). These include myeloblasts through the band stage.

Back 132

medullary formation compartment

Front 133

The __________ contains those cells that are fully- or almost fully developed and are waiting for a “signal” to enter the circulation. These include band and segmented cells. While it is the segmented cells that are normally put into circulation, it is
not uncommon for band cells to enter this pool, especially in cases of infections where
there is increased demand for neutrophils.

Back 133

Medullary reserve compartment

Front 134

Neutrophils enter the __________ and circulate for a few days. They then begin
the exit from the vascular system by first adhering to the inner wall of the vessel
(AKA ________). Then, by the process of diapedesis, they enter the connective tissues.

Back 134

circulating pool
/
marginal pool

Front 135

Conditions that lead to detachment include What?

Back 135

strenuous exercise, release of adrenaline, etc.