Cellular microscopy 2: blood cells, urine cells and parasites Flashcards
Define ERYTHOCYTES
Red blood cells. They are small, biconcave discs found in the blood. They have NO NUCLEUS
Roughly how many erythrocytes are there per ml?
5-8 million
What is the main function of erythrocytes?
To oxygenate tissues
What are the two different ways to measure haemoglobin levels in the blood?
Using a pulse oximeter
Arterial blood gas analysis (using an EPOC machine)
What is the size of an average erythrocyte?
7 micrometres
Where does destruction of erythrocytes happen?
In the spleen and the liver. Part of the erythrocyte is preserved and reused and the waste pigment is broken down
What is important to remember about canine red blood cells?
They are paler than cat erythrocytes when viewed under a microscope
Define PLASMA
The fluid component of blood, where RBCs are found
Define HAEMOLYSIS
The destruction of red blood cells
What are possible causes of haemolysis?
Possibly disease (such as IMHA)
Poor blood sampling technique (e.g. using too small a needle or shaking the sample tube)
Define CRENATE
The shrinking/shrivelling of red blood cells. Presence of a lot of crenation could indicate pathology and should be reported to a vet
Define ANAEMIA
Lack of red blood cells
What is the average lifespan of an erythrocyte?
120 days in circulation
Define a LEUCOCYTE
A general term for all white blood cells. Have a lifespan of around 21 days, and are larger than erythrocytes. They are split into granular and agranular cells initially and then further identified
Define GRANULOCYTES
Make up 70% of all leucocytes. They have visible granules when stained, and generally have irregularly shaped nuclei
What general shape is the nucleus of a granulocyte?
They are polymorphonuclear, and have irregularly shaped nuclei
What percentage of all leucocytes are granulocytes?
Around 70%
What are the most common types of granulocytes?
Neutrophils, basophils and eosinophils
Define EOSINOPHILS
Make up between 2-10% of all circulating leucocytes, they help to inhibit allergic response and secrete anti-inflammatory substances in response to parasitic infections. They have a BILOBE NUCLEUS
What is the role of an eosinophil?
They help to inhibit allergic response and secrete anti-inflammatory substances in response to parasitic infections
Define EOSINOPHILIA
An increase in eosinophils
Define EOSINOPENIA
A decrease in eosinophils. Very rare but still difficult to identify due to their low numbers anyway
What does the suffix ‘phil’ mean?
Literally means ‘loving’
What does the suffix penia mean?
To lack, or have a deficiency
Define a BASOPHIL
They are very rare and make up only 0.5-1% of all circulating leucocytes. They release histamine and heparin and are generally since in allergic reactions. Have an ELONGATED NUCLEUS
What colour do basophils stain?
Blue
Define NEUTROPHILS
Make up 60-70% of all circulating leucocytes, with their presence indicating infection. Have a MANY LOBED NUCLEUS.
Often pale, as they do not stain well
Define NEUTROPENIA
A decrease in neutrophils, likely due to a chronic bacterial infection that is too strong
Define NEUTROPHILIA
An increase in neutrophils, likely in response to infection
What are immature neutrophils referred to as?
Band form neutrophils. They have a HORSESHOE SHAPED NUCLEUS
Why would you see the presence of band form neutrophils?
Sometimes released early from bone marrow in response to chronic infection
What colour do eosinophils stain?
They easily take on eosin, and stain red
Define AGRANULOCYTES
White blood cells with no visible granules (except large lymphocytes). They have uniformly shaped nuclei
What are some examples of agranulocytes?
Monocytes and lymphocytes
Define LYMPHOYCYTES
Make up around 30% of circulating leucocytes. They are responsible for active immunity, and are important for the immune response. They have a LARGE UNIFORM NUCLEUS that fills most of the cell
What are the two types of lymphocytes?
Small lymphocytes and large lymphocytes
Define ANTIBODIES
Also called immunoglobin. Used by the immune system to identify and neutralise foreign objects such as pathogenic bacteria and viruses
Define SMALL LYMPHOCYTES
Divided in to B and T cells. They both allow for adaptive immune response to infectious agents
- T cells undergo phagocytosis
- B cells create antibodies. They are linked to antigens and are bacteria/virus specific
Define LARGE LYMPHOCYTES
Often granular, referred to as natural killer cells. They identify and destroy body cells that have become infected or are no longer functional
Define LYMPHOPHILIA
An increased number of lymphocytes
Define PHAGOCYTIC
A cell that carries out a lot of phagocytosis is phagocytic
Define LYMPHOPENIA
A decreased number of lymphocytes. May be seen in stressed animals - the presence of cortisol can supress the immune system
Define MONOCYTES
Make up 5-6% of circulating leucocytes. They are the largest of the leucocytes. They spend a short time in circulation and then migrate to the tissue to become macrophages. They are only seen in cases of infection that cannot be resolved by neutrophils/ Have a BIOLOBED NUCLEUS
Define MACROPHAGES
They sit stable and dormant in tissue until needed. They phagocytose bacteria and secrete pro inflammatory and antimicrobial mediators
