Haematology Flashcards
Define HAEMATOLOGY
Haematology is the study of the cellular components of blood, associated clotting factors and the tissues that form, store or circulate blood.
What is the cell mediated immune response?
- phagocytes are at the site of infection within a few minutes
- they engulf and destroy the foreign bacteria (phagocytosis)
- they then travel to a lymph node
- the antigen present activates helper T-cells
- B+T cells activated. These fight disease
What is the humeral immune response?
- B lymphocytes secrete antibodies. These antibodies are antigen specific
- they disable the antigen and label it for attack
Define an ANTIBODY
An antibody is a protein that binds very tightly to their target antigen. They are a defence against infection in vertebrates
What is the difference between the innate response and the adaptive response?
The innate response occurs early in infection. Macrophages bind to the organism and are antigen presenting. They have a non-specific recognition system
The adaptive response is later on, often during reinfection. Individual pathogens are recognised and B-cells release antibodies. T-cells control the B-cell development and interact with APC, to destroy virus infected cells.
What is the difference between acquired and passive immunity?
In acquired immunity, the individual gains immunity through exposure to a pathogen and possibly getting the disease.
In passive immunity, the individual gains antibodies from elsewhere. Often short term, e.g. mare to foal during neonatal and natal development.
Define RETICULOCYTES
Reticulocytes are immature red blood cells found in bone marrow.
What is the process of RBC production?
- production of RBCs is controlled by erythropoiten, the hormone released by the kidney. Its release is stimulated by hypoxia (lack of oxygen)
When eyrthropoiten released: - more stem cells differentiate into RBCs
- stages of RBC development speed up
- transit time out of bone marrow decreases
- reticulocytes are released
Define a LYMPHOCYTE
A lymphocyte is a white blood cell that accumulates in the lymph and lymph nodes. Also found in the spleen and in the blood. Two main types: B and T cells.
There are 4 types of T-cells:
- helper (associated with B cells), suppressor( regulates the immune response), killer (secrete cellulotoxic substances) and memory (retain memory for future protection).
What is the process of B-lymphocyte immunity?
- only last for a few days
- firstly lost of different B-cells
- an antigen binds to B cell that has an antibody on its surface that fits the antigen
- B-cell is stimulated to make more of the same antibody and secrete it
What is the process of T-lymphocyte immunity?
- macrophage presents antigen
- helper T-cells bind to the APC
- T-cells are attracted to the area
- T-cells are stimulated to differentiate
- foreign cells killed, promotes new blood vessels
What are some methods of blood collection?
- Syringe and needle
- Vacutainer - double ended needle that draws a predetermined volume of blood
- Anticoagulant - prevents blood changing to a solid or semi solid state
What are some ways to measure RBCs?
- Packed Cell Volume (PCV) - percentage of the blood volume occupied by RBC
- Mean corpuscular volume (MCV) - average volume of the individual erythocyte. Calculated from the PCV and the total red blood cell count.
- Mean corpuscular haemoglobin concentration (MCHC) - measure of haemoglobin concentration in RBCs. Calculated from PCV and total haemoglobin concentation
Define ERYTHROCYTOSIS
Erythrocytosis is an abnormally high PCV.
Define ANAEMIA
Anaemia is a condition in which there is a deficiency of red blood cells or haemoglobin in the blood.
