Prac 6 CVRS - Blood Flashcards
Lifespan of Erythrocyte
120 Days
Why are erythrocytes anucleate,
lost their nuclei during development
Why are they Biconcave disks
Loss of the cell nucleus
Major Function of Erythrocytes
Transport oxygen and carbon dioxide via the hemoglobin which fills most of the cytoplasm.
Where are Erythrocytes formed?
Bone marrow
What happens before erythrocytes are released into the bloodstream
normally lose their nuclei and cytoplasmic organelles
What are reticulocytes
immature red cells still containing some visible ribosome remnants that are released into the bloodstream
Stain for blood Smear
Leishman’s stain
What do reticulocytes look like with Leishman’s stain?
These can be seen to contain blue-staining remnants of cytoplasmic organelles, notably the remains of the ribosomes used to synthesize the hemoglobin
Multi-lobular nucleus?
neutrophils
Prominent granules?Dark blue granules?
basophil
Prominent granules?Bright pink granules?
eosinophil
Small cells with a darkly stained nucleus and little cytoplasm?
lymphocyte
Cells with a kidney-shaped nucleus?
monocyte
Much smaller than red cells?
Platelets
Normally they are the most numerous type of white cell in peripheral blood
neutrophils
Features of neutrophils
They are phagocytic and are able to operate in hostile environments (e.g. low oxygen tensions).
most of them leave the blood stream to enter tissues, particularly at sites of infection.
granulocytes
Basophils
Neutrophils
Eosinphils
agranulocytes
monocyte
Lymphocyte
Another name for eosinophils
Acidophilic leukocytes
Structure of eosinophils
They have a bi-lobed or tri-lobed nucleus and prominent dark pink granules.
Lifespan of Eosinophils
They remain in the circulation for only a few hours and show a diurnal fluctuation in numbers, being highest in the morning.
Eosinophils function
They are able to phagocytose antigen/antibody complexes and are especially associated with parasitic infections which they are able to counteract.
Eosinophils function
They are able to phagocytose antigen/antibody complexes and are especially associated with parasitic infections which they are able to counteract.
least common of all the white cells
Basophils
Structure of Basophils
They contain unmistakably large (blue) granules which appear to fill the cell.
Function of basophils
They have a similar role to mast cells (found in most tissues, especially alongside blood vessels and in the mucosa of the gut). When stimulated they secrete histamine and a range of other vasoactive substances that increased blood flow to the local area.
Where are lymphocytes mostly based?
within lymph nodes and within connective tissues of organs and tissues.
How can we distinguish between different types of lymphocyte?
It is not possible to distinguish between these subtypes using conventional stains, although immunohistochemistry can be used to distinguish between them.
What do lymphocytes look like with Leishman’s stain?
lymphocytes have a dark staining, almost round nucleus and a pale grey/blue cytoplasm devoid of granules
What are monocytes?
Monocytes are immature circulating forms that differentiate into one of several cell types once they leave the blood stream and take up residence in the connective tissues. Many monocytes differentiate into tissue macrophages.
What do monocytes look like?
Monocytes are characterised by a kidney shaped (reniform) nucleus that often appears eccentrically placed. It has a large amount of pale blue cytoplasm.
What are platelets?
Platelets are small fragments of cells without a nucleus which are derived from multi-nucleate megakaryocytes in the bone marrow. They contain a range of cell organelles, including four different types of granule
Where are erythrocytes formed in adults
In adults, haematopoiesis is confined to the marrow of the flat bones and proximal ends of the humeri and femurs.
Where are erythrocytes destroyed in adults
Red cells are destroyed in the liver and spleen.
Where are red blood cells formed in utero
In utero they are formed first in the yolk sac, then in the liver, then in the bone marrow
Which is the predominant leukocyte
Neutrophil
Which cell type increases in patients with worms
Eosinophils play a role in our defence against parasitic infections and their numbers increase in patients with parasites such as worms.
Both basophils and eosinophils bear receptors to what
IgE -but they are antagonistic in their function
How do eosinophils and eosinophils have antagonistic functions
Basophils release histamine (and eosinophils counter the action of histamine).
What do Eosinophils contain
Charcot-Leyden crystals.
Unlike basophils and eosinophils, neutrophils do not bear
IgE receptors
Basophils become
Mast cells
Monocytes give rise to the following cells (5)
Tissue macrophages - everywhere Kupffer cells – liver Osteoclasts – bone Antigen presenting cells - everywhere Alveolar macrophages – lung
. Which of these is the multipotential haematopoeitic stem cell?
Haemocytoblast
What are Platelets
Platelets are membrane-bound fragments of the cytoplasm of megakaryocytes
Where and how does Erythropoiesis occur
Erythropoiesis occurs away from bony trabeculae. Cells start basophilic and become eosinophilic. They gradually lose organelles (as they gain haemoglobin). The nucleus stays round and is eventually extruded. The cells get smaller as they mature.
