HISTOLOGY 1

Question 1

Blood is a …. consisting of cells suspended in …

Answer 1

Specialized connective tissue,
A fluid extracellular material called plasma.

Question 2

The formed elements circulating in plasma are … 3

Answer 2

Erythrocytes (RBCs)
Leukocytes (WBCs)
Platelets

Question 3

Blood consists of …

Answer 3

Plasma & Blood cells

Question 4

Blood cells make up about … of the blood.

Answer 4

45%

Question 5

Blood cells are split into 3, with %

Answer 5

RBCs (Erythrocytes) 44%
WBCs (Leukocytes) 1%
Platelets (Thrombocytes) less than 1%

Question 6

Terminally differentiated structures lacking nuclei and completely filled with the oxygen carrying protein hemoglobin.

Answer 6

Erythrocytes

Question 7

The only blood cells whose function does not require them to leave the vasculature.

Answer 7

Erythrocytes, RBCs

Question 8

Normal diameter of RBCs

Answer 8

7.5um

Question 9

Average no# of RBCs in females

Answer 9

4.5 million/ mm³

Question 10

Average no# of RBCs in males

Answer 10

5.5 million/mm³

Question 11

The pink color of RBCs is due to

Answer 11

Hemoglobin content

Question 12

RBCs with normal Hb content are called

Answer 12

Normochromic

Question 13

Human RBCs survive in the peripheral blood for how many days
Lifespan of RBCs

Answer 13

120 days

Question 14

Old RBCs are removed by

Answer 14

By macrophages in the spleen and bone marrow.

Question 15

Shape of RBCs

Answer 15

Rounded bioconcave discs

Question 16

The rounded bioconcave disc shape of RBCs provides

Answer 16

Provides large surface to volume ratio facilitating gas exchange, maximising the absorption of oxygen.

Question 17

Why are erythrocytes flexible? Able to deform.

Answer 17

It permits them to bend and adapt to the small and irregular, to fit in small vessels.

Question 18

Erythrocytes assume a ……. shape at the angles of capillary bifurcations.

Answer 18

Cuplike

Question 19

RBCs adhere together, forming an arrangement resembling stacks of coins called

Answer 19

Rouleaux formation/appearance

Question 20

Rouleaux formation indicates the presence of pathology due to…

Answer 20

Low flow velocity or increased plasma viscosity.

Question 21

The cytoplasm of RBCs contains…

Answer 21

Mainly hemoglobin enclosed by the cell membrane.
They have no nuclei or organelles.

Question 22

RBCs

Answer 22

Red blood CORPUSCLES, not true cell.

Question 23

The erythrocyte membrane is composed of…

Answer 23

A lipid bilayer with integral proteins, to which glycans are linked to on the external surface.

Question 24

The integral proteins + glycans are responsible for…

Answer 24

ABO blood grouping

Question 25

Beneath the lipid bilayer of RBCs lies...

Answer 25

The cytoskeleton

Question 26

Cytoskeleton of erythrocytes, a protein network consisting of...

Answer 26

Spectrin & Actin

Question 27

Function of the RBCs cytoskeleton

Answer 27

Provides the capacity for deformability, flexibility, and elasticity, and preserves the bioconcave shape. Stabilises the structural integrity of the lipid bilayer.

Question 28

Allows erythrocytes to be flexible

Answer 28

Cytoskeleton

Question 29

Another name for cell membrane

Answer 29

Plasmalemma

Question 30

Immature erythrocytes

Answer 30

Reticulocytes

Question 31

Reticulocytes constitute NORMALLY about ...% of the circulating erythrocytes.

Answer 31

1%

Question 32

RBCs constitute NORMALLY about ...% of the circulating erythrocytes.

Answer 32

99%

Question 33

Size of reticulocytes

Answer 33

8um, slightly larger than mature erythrocytes.

Question 34

Contents of reticulocytes

Answer 34

No nuclei, but contains some free ribosomes and a few mitochondria.

Question 35

Increase in the number of reticulocytes occurs...

Answer 35

In cases of hemorrhage and high altitude.

Question 36

Contents of mature erythrocytes

Answer 36

Only hemoglobin

Question 37

Staining of mature erythrocytes

Answer 37

Eosinophilic, deep pink.

Question 38

Staining of reticulocytes

Answer 38

Blue, supravital stain, brilliant cresyl blue

Question 39

Non nucleated cytoplasmic fragments derived from giant cells in the bone marrow

Answer 39

Thrombocytes, Platelets.

Question 41

Platelets are derived from

Answer 41

Megakaryocytes

Question 42

Normal number of platelets in blood

Answer 42

150,000 - 400,000 per cubic millimeter of blood

Question 43

Life span of platelets

Answer 43

10 days

Question 44

Size of platelets

Answer 44

2um

Question 45

The smallest blood element

Answer 45

Platelets, Thrombocytes

Question 46

Structure of platelets under LM

Answer 46

Avoid non nucleated mass of cytoplasm surrounded by a cell membrane. It has a lightly stained peripheral zone called hyalomere and a darker stained central zone called granulomere.

Question 47

Darker stained central zone

Answer 47

Granulomere

Question 48

Lightly stained peripheral zone

Answer 48

Hyalomere

Question 49

Under the LM, platelets appear...

Answer 49

Appear in clusters/clumps.

Question 50

Under the EM, platelets have a cell membrane and .....

Answer 50

A thick cell coat containing glycocalyx.

Question 51

Function of the thick cell coat ( glycocalyx ) on platelets

Answer 51

Cell attachment and adhesion.

Question 52

Under the EM, the peripheral zone contains ... structures.

Answer 52

4

Question 53

Under the EM, the central zone contains ... structures.

Answer 53

4

Question 54

Function of the bundles of microtubules, which are arranged parallel to the cell membrane (in platelets)

Answer 54

They act as an internal skeleton that maintains the oval shape of platelets.

Question 55

Function of the bundle of microfilaments in platelets

Answer 55

Help in platelet movement and aggregation.

Question 56

Function of open canalicular system of vesicles connected to invaginations of the membrane (in platelets)

Answer 56

To facilitate degranulation of platelets

Question 57

Function of the dense tubular system (platelets)

Answer 57

Store calcium ions.

Question 58

The dense tubular system is derived from...

Answer 58

ER

Question 59

The structures in hyalomere

Answer 59

Microtubules Microfilaments Open canalicular system Dense tubular system

Question 60

The structures in granulomere

Answer 60

Mitochondria Glycogen granules Numerous vesicles Membrane bound dense granules

Question 61

Invaginations of the cell membrane and cell coat in granulomere

Answer 61

Numerous vesicles

Question 62

Membrane bound dense granules

Answer 62

Alpha granules Delta granules Lambda granules

Question 63

Alpha granules contain...

Answer 63

Platelet specific factors

Question 64

Delta granules contain...

Answer 64

Ions, ATP, ADP, & serotonin.

Question 65

Lambda granules contain...

Answer 65

Lysosomal enzymes