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Basophils

Basophils have cytoplasmic granules of varied size and are named for their granules’ ability to absorb the basic dye methylene blue ( [link] ). Their stimulation and degranulation can result from multiple triggering events. Activated complement fragments C3a and C5a, produced in the activation cascades of complement proteins, act as anaphylatoxins by inducing degranulation of basophils and inflammatory responses. This cell type is important in allergic reactions and other responses that involve inflammation. One of the most abundant components of basophil granules is histamine , which is released along with other chemical factors when the basophil is stimulated. These chemicals can be chemotactic and can help to open the gaps between cells in the blood vessels. Other mechanisms for basophil triggering require the assistance of antibodies, as discussed in B Lymphocytes and Humoral Immunity .

Mast cells

Hematopoiesis also gives rise to mast cells , which appear to be derived from the same common myeloid progenitor cell as neutrophils, eosinophils, and basophils. Functionally, mast cells are very similar to basophils, containing many of the same components in their granules (e.g., histamine ) and playing a similar role in allergic responses and other inflammatory reactions. However, unlike basophils, mast cells leave the circulating blood and are most frequently found residing in tissues. They are often associated with blood vessels and nerves or found close to surfaces that interface with the external environment, such as the skin and mucous membranes in various regions of the body ( [link] ).

a) Mast cells in blood. Mast cells are large purple cells, red blood cells are small pink cells with a clear center. b) mast cell outside of blood.
Mast cells function similarly to basophils by inducing and promoting inflammatory responses. (a) This figure shows mast cells in blood. In a blood smear, they are difficult to differentiate from basophils (b). Unlike basophils, mast cells migrate from the blood into various tissues. (credit right: modification of work by Greenland JR, Xu X, Sayah DM, Liu FC, Jones KD, Looney MR, Caughey GH)
  • Describe the granules and nuclei of neutrophils, eosinophils, basophils, and mast cells.
  • Name three antimicrobial mechanisms of neutrophils

Part 3

Angela’s tests come back negative for all common allergens, and her sputum samples contain no abnormal presence of pathogenic microbes or elevated levels of members of the normal respiratory microbiota. She does, however, have elevated levels of inflammatory cytokines in her blood.

The swelling of her airway has still not responded to treatment with antihistamines or corticosteroids. Additional blood work shows that Angela has a mildly elevated white blood cell count but normal antibody levels. Also, she has a lower-than-normal level of the complement protein C4.

  • What does this new information reveal about the cause of Angela’s constricted airways?
  • What are some possible conditions that could lead to low levels of complement proteins?

Jump to the next Clinical Focus box. Go back to the previous Clinical Focus box.

Agranulocytes

As their name suggests, agranulocytes lack visible granules in the cytoplasm. Agranulocytes can be categorized as lymphocytes or monocytes ( [link] ). Among the lymphocytes are natural killer cells, which play an important role in nonspecific innate immune defenses. Lymphocytes also include the B cells and T cells, which are discussed in the next chapter because they are central players in the specific adaptive immune defenses. The monocytes differentiate into macrophages and dendritic cells , which are collectively referred to as the mononuclear phagocyte system.

Questions & Answers

differences between prokaryotes and eukaryotes
Taiwo Reply
Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not.
Margo
hello
usman
margo calvi....its your simple difference
Sadiqur
give me the name of good microbiology books to download
Shahid Reply
thank u
Shahid
bacteriology encyclopedia
Mzafar
Who invented microbes?
manor Reply
Which year did Robert koch invented the microbes?
manor
Robert Koch
Matilda
Antony Van Leeuwenhoek invented microbes through a designed single lensed microscope.
Mohamed
what is microbiology
Nyoik Reply
microbiology is the study of micro organisms. this can be multicellular,unicellular & acellular
Janet
what is the difference between DNA/RNA
kanaaLka
DNA is a double stranded molecule while RNA is a single stranded molecule
Lovely
who is the inventor of microscope
Alberta
What are antibodies?
Happy Reply
they are immune cells that are released by immune system to fight strangers like microbes
Ahmed
a blood protien produce in response to an counteracting a specific antigen
Pooja
Why salmonella typhi is harmful protozoan?
Saily Reply
because make typhoid that is considered as a food born illness
Ahmed
Name any five modes of transmission.
Happy
what are the scientific names and common names of some microbes
Rich Reply
Staphylococcus aureus - staph Streptococcus pyogenes - strep Botulism - Clostridium botulinum Rocky Mountain spotted fever - Rickettsia rickettsii Diphtheria - Corynebacterium diphtheriae Gonorrhea - Neisseria gonorrhoeae
Tammy
what are the limitations of the Koch's postulate
Naa
how a microorganism growth.
Zubair Reply
Is foetus a parasite to his or her mother? if yes and if no ho
Mashauri Reply
y
Yusri
yes
Yashkin
yes
Zubair
yes it a parasite to the mother because it feeds on the mother for survival
Beatrice
yes
Redwan
no
Elasha
definition of a parasite: an organism that lives in or on an organism of ANOTHER species (its host) and benefits by deriving nutrients at the other's expense
Elasha
no because an organism can inky be a parasite if it causes harm to its HOST. And the fetus does not cause harm to its mother under normal conditions
aliyu
yes
Naa
what is biosensor in microbiology
Raja Reply
What are biosensor
Raja
what's are biosensor
Raja
what is microbiology defination
Rinku Reply
microbiology is the study of small or manuit organisms which cannot be seen with our nacked eyes unless with the aid of the microscope
Brandina
is the study of living organisms which are not directly visible to a direct eye but can only be seen under a microscope
Ipa
ok
Ipa
microbiology is the study of living organisms of microscopic size it is also the study of micro organisms with their form structure reproduction psychology metabolism and classification
Priyanka
ok
Aminu
Microbiology are the study of microorganisms either microscopic or sub microscopic creaters mainly unicellulars, multicellulars and subcellulars. Such as protozoa,bacteria and viruses.
Rana
it is the biological study of viruses, fungi, protozoa, bacteria which in collective name are called micro organisms, unlike microscopic organisms being invisible, that requires a magnifications with the help of a microscope.
Mohamed
what are the importances of Microbiology?
Erick Reply
don't know
SINGLE
we obtained the insulin from the bacteria. and some microorganisms are decomposer in ecosystems.
Zubair
nitrogen in the air is fixed into the soil by microbes example is nitrobactor
Matilda
yes
Zubair
how a weak immune region where microorganisms attack easily?
Zubair Reply
with examples differentiate gram positive from gram negative bacteria
Mary Reply
Differentiate gram positive from gram negative
Mary
I have no idea
Zubair
hello
Kuonain
and example of gram negative is E. coli
Pooja
gram positive stain purple when subjected to gram stain whilst gram positive bacterial has thick wall composed of peptidoglycan
Matilda
ok
Zubair
what is a process of gene expression in eukaryotes ?
Nayyab Reply
pls help us with the answer
Abdussalam

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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