CVS Flashcards
How much of the blood is the cellular component?
45%
What is haemocrit and what is the normal haemocrit in a human?
The volume of read blood cells, normally 0.45
What is haemopoiesis?
The process of the production of blood cells and platelets which continues throughout life
Where does haemopoiesis?
In adults- Bone marrow
In embryonic life and infancy- Other sites
What is the lifetime of an erythrocyte and how many are produces per second?
120 Days
2 million produced per second
What is the lifetime of a platelet?
7-10 Days
Where are the precursor cells of red blood cells located and what is a young red blood cell known as?
In adults- The axial skeleton
In children- All bones
In Utero- The yolk sac, the liver, the spleen
If they are found in the blood, it is a sign of leukaemia
Young red blood cells are known as reticulocytes
Describe the hormonal growth factors that stimulate the precursor stem cells to proliferate?
Erythropoietin (made in the kidney)- Stimulates erythrocytes
G-CSF (granulocyte colony stimulating factor)- White Blood Cells
Tpo- Platelets
What causes the oxygen disassociation curve to shift?
Shifts right when pH is decreased or temperature increases
What does a red blood cell consist of?
Membrane to enclose haemoglobin, Enzymes of glycolysis, and haemoglobin
Describe Haemoglobin
Carries oxygen from lungs to tissues where it transfers oxygen to myoglobin in muscles. Haemoglobin is formed of 2 alpha and 2 beta chains and 4 haem groups.
How do the various blood types work?
There is a gene that results in the synthesis of A antigens on red blood cells, and a gene that results in the synthesis of the B antigen. Having neither= Type O (Most common) Having AB (Most rare) Having Just A (More common than B) Having just B
What are the antibodies/antigens in the blood of each blood type?
Type A= has anti-B antibodies in plasma, A antigen is co-dominant
Type B= Has anti-A antibodies in plasma, B antigen is co-dominant
Type AB= neither antibodies, has A and B antigens on surface of RBC
Type O= has both antibodies in plasma and no antigens. O antigen is recessive
What blood type is universal recipient and universal donor?
Universal recipient= Type AB
Universal donor= Type O
What are the type of antibodies used in blood types?
Anti-erythrocyte antibodies known as natural antibodies
Explain rhesus blood types
C,D,E antigens. Rhesus positive means the D antigen is present, rhesus negative means D antigen is not present
What is the bounds for normal haemoglobin?
12.5-15.5 G/dl
What is polycthaemia?
Higher than normal haemoglobin, caused by smoking, lung diseases, inefficient lungs meaning less O2 is exchanged so more haemoglobin is required
What are the symptoms and signs of anaemia?
Symptoms- Tiredness, lethargy, malaise, reduced exercise tolerance, shortness of breath on exertion and angina
Signs- Palor, Pale mucus membranes and palmar creases, glossitis, angular stomatitis, kylonychia
Describe iron deficiency anaemia
Iron is needed for haemoglobin production, lack of iron results in reduced production of small red cells
Low haemoglobin and MCV<80 fl
Causes- Occult gastrointestinal bleeding, menorrhagia, dietry
Describe macrocytic anaemia
Large red blood cells. Macrocytosis can occur without anaemia (caused by liver disease, alcohol and hypothyroidism). In macrocytic anaemia, macrocytosis is a sign of it
Describe B12 and Folate deficiency anaemia
Vitamin B23 and foalte are needed for DNA synthesis, thus with a B12 and folate deficiency red blood cells cannot be made in the bone marrow and thus less are released. This deficiency will effect all dividing cells but bone marrow is most active so it is affected first. Can be caused by damage to the stomach if intrinsic factor is not being produced by parietal cells, or by pernicious anaemia. Folate deficiency can be caused by malabsorbtion, dietary or an increased need.
Describe haemolytic anaemia
Normal cell production but decreased lifespan
What can cause congenital anaemia?
Membrane issues e.g. spherocytosis
Enzyme issues e.g. pyruvate kinase deficiency
Haemoglobin issues e.g. Sickle cell anaemia/ thalassaemia