lecture 8 Flashcards
what are the commonest type of WBCs?
(% = ?)
neutrophils
(40-65%)
how do neutrophils appear in the killed and living states?
(diameter = ?)
- killed state –> round
- living state –> irregular shape
d= 12 micro
what color are neutrophil’s granules? what type are they?
- fine pinkish granules
- primary or azurophilic
what are neutrophils’ granules rich in?
enzymes (myeloperoxidase, acid phosphatase, esterase)
what is the function of the enzymes found in neutrophils?
which is the most important one?
important in the ingestion of foreign particles
myeloperoxidase
what is another name for primary granules?
azurophilic granules
what is another name for primary granules?
azurophilic granules
how many segments can a neutrophil have? what are some conditions associated with them?
- normally 2-5 segments
- 2-3 majority
- 4-5 minority
- increase in nb of cells with 4-5 segments –> shift to the right
- increase in the nb of segments > 5 –> hypersegmentation
hypersegmentation is encountered in a nb of conditions, such as:
- megaloblastic anemia
- iron deficiency anemia
what do you know about the drumstick chromosome?
- is an inactivated X chromosome
- seen in 2-5% of neutrophils in normal females with an XX chromosomal pattern
- used to identify the gender of a person
neutrophils live for how long in the circulation?
7-9 hours
where and how do neutrophils go to after circulating in PB?
- they go to the tissues
- via diapedesis
diapedesis: squeeze between junctions of endothelial cells
what is the main function of neutrophils? what is it also known as?
- injest and kill microoorganisms (must be able to reach the site of infection in order to do so)
- known as a microphagocyte (since it cannot injest large particles such as parasites)
what are the 2 types of neutrophil movements?
- random movement seen under microscopic observation
- unidirectional movements towards the stimulus in the presence of a chemotactic factor, process called chemotaxis
what are some chemotactic factors?
- bacterial products
- complements components (C5a)
what happens once the neutrophil reach the invading organism?
(all the steps)
- forms a membrane folding (pseudopodia) around the bacterial cell
- engulfs it into a phagocytic vacuole (phagosome)
- fuses with a lysosome
- neutrophil releases its lysosomal contents into the phagocytic vacuole (degranulation)
- kills the bacteria
what is degranulation?
it is when the neutrophils release all its lysosomal content into the phagosome containing the bacteria
what happens if there was a defect in any of the steps in the phagocytic process?
- result in a disease state
- recurrent infections
- disorder known as Chediak-Higashi syndrome
how do neutrophils leave the body?
via excretions from
* intestinal tract
* urinary tract
* lungs
* salivary glands
what is the size of eosinophils?
d= ?
eosinophils are a bit larger than neutrophils
d= 12-17 micro
what are the characteristics of the nucleus of the eosinophil?
shape
- bilobed (segmented)
- sometimes has a small triangular lobe in the middle
what color are eosinophils’s granules? what type are they?
- golden-yellow in color
- large uniform refractile granules
what is the function of eosinophils?
(in details)
- function as phagocytes but move more slowly + have less intracellular killing ability than neutrophils
* respond to chemotactic factors but prefer factors secreted by mast cells & basophils (histamine)
* drawn to the site of immediate hypersensitivity reactions (allergic reactions) - act as killer cells
* have receptors on its surface for certain parasitic larvae
* larva enters the body –> detected by receptors –> eosinophils come & stick to the larvae –> degranulate (release their granules) –> kill the parasite
the function of eosinophils as killer cells is observed with all parasitic infestations
(T/F)
false, not will all parasitic infestations
only with parasites that have some tissue cycle in the body
what are the chemotatctic factors that eosinophils prefer to respond to?
factors secreted by mast cells & basophils (histamine)
what is the life span of eosinophils in the circulation?
- lifespan is short
- 5-8 hrs in circulation
where do eosinophils go after circulation? and for how long?
- go to the same tissues as neutrophils
- remain for many days
eosinophils remain in the tissues then pass in the secretions very rapidly
(T/F)
false, neutrophils
what is the size of a basophil?
similar in size as the eosinophil
what are the characteristics of the nucleus of a basophil?
2 or 3-lobed nucleus
what color are basophils’s granules? what type are they?
- large black granules
- vary in size
- cover the whole cell, nucleus, cytoplasm
what are basophils’ granules rich in?
when are they released?
contain very important biologic substances:
* histamine
* heparin
* prostaglandins
* leukotrienes
released during severe allergic reactions (anaphylactic reaction /or allergic type 1 reactions/ hypersensitivity reaction type 1)
+ responsible for the different clinical symptoms associated with them
what is the function of basophils?
- injest particles (have less phagocytic capacity than eosinophils+neutrophils)
- secretory function (releases its granule contents to the outside of the cell by exocytosis following exposure to stimulus)
- participates in allergic reactions
what is the lifespan of basophils?
short lifespan (similar to eosinophil)
what happens to basophils after they enter the tissues?
it is still unknown
monocytes are not known as granulocytes since they do not contain specific granules
(T/F)
false, they are not known as granulocytes yet they contain many specific granules
what is the size of a monocyte?
d=?
large cell
d= 12-20 micro
what is the largest cell in the PB?
monocyte
how do monocytes appear in the fixed and living states?
- fixed state (alcohol) –> round
- living state –> irregular
what characteristics does the nucleus of a monocyte have?
- quite large
- lies to one side of the cell
- nuclear shape is unimportant since it can assume many shapes
- has very delicate chromatin (lacy or dentel like)
what cells have their nucleus lying on one side of the cell?
(from this and previous lecture)
- monocytes
- metamyelocyte
- unsegmented neutrophil (band cell)
how many nucleoli do eosinophils and basophils have?
0
how many nucleoli do monocytes have?
0
what are the characteristics of the cytoplasm of a monocyte?
what does it contain
- abundant
- blue-gray in color
- thick & opaque in appearance
- rich in many specific pinkish granules, with or without occasional vacuoles
do monocytes contain granules? if yes what do they contain
- yes monocytes contain granules
- may contain occasional vacuoles
- rich in many enzymes, most important myeloperoxidase
granules of neutrophils and basophils contain enzymes (myeloperoxidase, acid phosphatase, esterase)
(T/F)
false, neutrophils and monocytes
basophils contain important biological substances
what is the function of monocytes? what is it also known as?
- in phagocytosis
- also known as macrophages (can phagocytize large particles, such as whole cells & parasites)
- play a major defense system
where is the monocyte formed?
in the BM
how long do the monocytes circulate in PB?
around 12 hours
where do monocytes go after circulation?
tissues such as the spleen and lymph nodes
they become tissue macrophages
how long do monocytes remain in the tissues?
can remain alive for several months
unlike other blood cells, what can monocytes do in the tissues?
they can divide in the tissues
what is the size of a lymphocyte?
d= ?
- is a variable cell
- can occur in varying sizes (small, medium, large)
d= 8-16 micro m
the larger the lymphocyte, the more abundant the cytoplasm will be
(T/F)
true
the adult lymphocyte is also known as:
the small lymphocyte
what is the commonest type of lymphocyte?
d= ?
small lymphocyte
d= 8-10 micro
what are the characteristics of the nucleus of a small lymphocyte?
(include chromatin)
- nucleus large compared to the size of the cell
- almost fills the whole cell (high nucleus/cytoplasm ratio)
- round/oval
- slightly indented (can see >1 indentation)
- chromatin quite dense & clumped (dont see chromatin detail –> nucleus appears as one mass)
how many nucleoli are seen in a small lymphocyte?
ya 0 ya it contains a nucleolus but cannot be seen under ordinary microscope
mahada byaarif
what are the characteristics of the cytoplasm of a small lymphocyte?
what does it contain
- it forms a thin rim around the nucleus (so small it cannot be seen)
- has a moderate to dark blue coloration
- completely transparent
- contains 1-2 nonspecific azurophilic granules (unimportant)
in children we find smaller lymphocytes
(T/F)
false, larger lymphocytes
what are the characteristics of the cytoplasm & nucleus of a medium lymphocyte?
d= ?
- cytoplasm is more abundant
- pale to moderately blue in color
- may or may not contain few nonspecific azurophilic granules
- nucleus round/ oval
- may be slightly indented
- chromatin clumped but not as dense
d= 10-12 micro
how many nucleoli are seen in a medium lymphocyte?
0
what are the characteristics of the cytoplasm & nucleus of a large lymphocyte?
d=?
- cytoplasm more abundant
- very pale blue
- may or may not contain few nonspecific azurophilic granules
- nucleus round/oval
- may be slightly indented
- chromatin coarse but to a lesser degree
d= 12-16 micro
how many nucleoli are seen in a large lymphocyte?
1 nulceoli may be seen
what is the function of lymphocytes?
- vital to the immune system
- production of circulating antibodies
- expression of cellular immunity
using special staining procedures, lymphocytes are negative for peroxidase, choracetate esterase, acid phosphates
(T/F)
false, peroxidase, chloracetate esterase, alkaline phosphates
using special staining procedures, lymphocytes are positive for:
acid phosphates
do lymphocytes respond to foreign antigens by phagocytizing them?
no, it reacts differently to these antigens
lymphocytes are not actively motile
(T/F)
false, they are actively motile, can move from the circulation to the tissues where it is needed
what are downy cells?
abnormal lymphocytes
when are downy cells incountered in PB?
in some disease conditions such as viral infections
what are the 3 types of downy cells?
- atypical lymphocyte
- blast-like lymphocyte with a hyperbasophilic cytoplasm
- plasmacytoid lymphocyte
