White cells (leucocytes) Flashcards
what is a normal white cell count (WCC)?
4-11 x 10 (9)/L
high tends to mean infection or cancer
low mean immunsuppression
what can cause a low WCC?
Common causes include: cancer treatment, like radiotherapy anti-psychotic drugs medication for an overactive thyroid some cancers, like leukaemia infections such as HIV or hepatitis autoimmune disorders, like rheumatoid arthritis
what 5 types of white cell are there?
neutrophils, lymphocytes, monocytes, eosinophils basophils.
what is the white cell differential (count)?
The differential reveals if the white cells are present in normal proportion to one another, if one cell type is increased or decreased, or if immature or abnormal cells are present. This information is helpful in diagnosing specific types of illnesses that affect the immune system.
which is the most common type?
neutrophils
what do neutrophils do?
these are the most abundant white blood cells, and are ‘phagocytes’ - that is, they ‘eat’ foreign organisms and kill them with internal poisons. They are important for fighting bacterial and fungal infections.
biggest association fighting bacterial infections
but also fungi
what of lymphocytes do?
25% normal WCC
specifically acting killers of infection and regulate the immune response. B-lymphocytes produce antibodies. T-lymphocytes act as messenger cells, directing the immune response.
biggest association = viral infections
(but also fight bacteria)
monocytes
5-10% normal WCC
Monocytes are phagocytes, like neutrophils, active against bacteria, fungi, and tuberculosis.
eosinophils
1-3 % normal WCC
increase during allergic attacks and some parasitic (worms) infestations
biggest association Allergies eg hayfever and asthma
basophils
<1% of normal WCC
(so called because their corase granules stain blue when exposed to a basic dye)
increasein
Which of the following white blood cells is capable of phagocytosis?
a) Basophil
b) Eosinophil
c) Lymphocyte
d) Neutrophil
Neutrophil
Feedback:
Phagocytosis is the process by which a cell can ingest and digest other cells. The two WBCs that are phagocytic in nature are neutrophils and monocytes.
what types of lymphocyte are there?
B cells which make antibodies that bind to pathogens to bring about their destruction.
T cells – CD4 or helper T cells coordinate the immune response. They are what become defective in HIV infection. They are important for defence against intracellular bacteria. CD8 or cytotoxic T cells are able to kill virus infections.
Natural killer cells are able to kill cells of the body which are not displaying a signal not to kill them as they have been infected by a virus or have become cancerous.
An increased white blood cell count is indicative of which disease?
a) Lupus
b) Leukaemia
c) Anaemia
d) Melanoma
Leukaemia
Feedback:
White blood cells increase in number during times of infection and disease within the body. In diseases such as leukaemia, normal leucopoiesis (formation of WBCs in the bone marrow) is affected. This results in a number of immature WBCs that rapidly divide within the bone marrow. Hence, the increase of WBCs.
leucocytosis
high white blood cell count
name three different types of granular leukocytes?
eosinophils, basophils, neutrophils
