Introduction to Blood Flashcards
What is average circulating volume of blood in a typical adult male ( 70 kg) and how is it distributed?
5 litres of blood
1L in lungs
3L in systemic venous circulation
1L in heart and arterial circulation
What are the functions of blood?
Carriage of physiologically active compounds (plasma)
Clotting (platelets)
Defence (white blood cells)
Carriage of gas (red blood cells)
Thermoregulation
Maintenance of ECF pH (7.4)
Platelets role in blood clotting?
-clotting factors need platelets to be present (platelets themselves do not participate in clotting cascade)
What is in blood?
Plasma, red blood cells, white blood cells and platelets.
What is percentage of body weight is plasma and percentage of blood?
4% of body weight is plasma and accounts for half of blood weight.
Composition of plasma?
95 % water
What isn’t water- made up of ions , hormones, enzymes , plasma proteins.
Role of plasma?
Circulates biologically active molecules & compounds
Composition normally kept within strict limits.
What are the three categories of plasma proteins?
Albumin
Globulin - Subdivided into alpha, ß, gamma globulins
Fibrinogen and other clotting factors
Where do plasma proteins perform their function?
Plasma proteins are not taken up by cells - perform their functions in the circulation. Compare with organic compounds e.g. hormones which use blood as a vehicle.
Describe Albumin’s role?
transports proteins that are not water soluble
Describe Globulin’s role?
Alpha and beta globulins transport proteins but gamma globulins function as antibodies.
Describe fibrinogen and other clotting factor roles?
Lipids get carried by fat soluble plasma proteins and can leave whenever.
Explain colloid oncotic pressure?
See A4 paper
What is hypoproteinaemia?
Abnormally low levels of circulating plasma protein
Why does hypoproteinaemia occur?
-prolonged starvation - can’t make proteins
-liver diseases -all plasma proteins are synthesized in liver
-intestinal diseases- problem with gut wall and can’t absorb protein to produce
-nephrosis (kidney problems) - losing proteins as kidney decides which components of fluid component of blood to keep
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Common characteristic of hypoproteinaemia?
oedema- build up of fluid in interstitial fluid because of loss of plasma proteins and loss of oncotic pressure.
What are erythrocytes?
Mature red blood cells
What are the types of white blood cell?
Neutrophils
Monocytes
Basophils
Eosinophil
Lymphocytes
What are the parts of formed and non formed components of blood?
formed- RBC, WBC and platelets
Non formed- plasma
What are reticulocytes?
Are almost but not quite mature red blood cells.
released into circulation and mature in next 24 hours.
Where are all blood cells in circulation from?
A population of undifferentiated pluripotent stem cells in the bone marrow. ( Pluripotent hematopoietic stem cell)
What is hematopoiesis?
The maturation of blood cells. The process by which cells develop from undifferentiated stem cells to erythrocytes and white blood cells.
Fates of undifferentiated pluripotent cells?
Either commits to being a lymphocyte or not.
If lymphocyte- differentiates to lymphocyte stem cells.
If not - uncommitted stem cell
What are committed progenitor cells?
Cells that have committed to being one particular type of blood cell.
Pathway for red blood cell?
(in bone marrow) Goes through process where has mitochondria and ribosomes to produce energy aerobically and produce protein.
-When reaching erythroblast loses ability to synthesize proteins and aerobically respire.
-As erythrocyte has to generate energy anaerobically
How much hemoglobin does RBC have?
Hemoglobin is all the protein that RBC will ever have.
Reticulocyte stage?
Un fully matured RBC is released into circulation. Goes through another 24 hours of maturation.
Megakaryocytes?
-Always stay in blood marrow but bits of their cell membrane and cytoplasm get released and are platelets.
What are myeloid cells?
All cells in circulation except from lymphocytes (lymphoid cells)
Myeloid leukemia or lymphoid leukemia?
Cancers affecting lymphoid cells or myeloid specifically.
Composition of erythrocytes?
Densely packed with Haemoglobin – protein concerned with gas transport.
Characteristics of erythrocytes?
Most abundant blood cell (4 - 6 x1012/L)
120 day lifespan.
Highly flexible, biconcave, non-nucleated, diameter 7-8m.