semester 2: L5: Blood Composition Flashcards
what is the composition of blood?
plasma is 55% of blood volume
cells are 45% of blood volume
whats in plasma, with the percent by weight?
water - 91%
proteins - 7%
other solutes - 2%
what other solutes does plasma contain?
Nutrients
Waste products
Hormones
Vitamins
Gases
what proteins are found in plasma?
albumine
globulin
fibrinogen
what do albumins and globulins do in plasma ?
maintain osmotic pressure
buffers
transports
what are leukocytes ?
white blood cells
what are the 5 types of white blood cells?
Lymphocytes Neutrophils Monocytes Eosinophils Basophils
what are white blood cells used for?
immune response
what is chemotaxis?
movement of leukocytes from the vessel lumen into into a damaged area
what do chemokines do?
act as chemoattractants, leading to the migration of immune cells to an infection site so they can target and destroy invading bodies
How many thrombocytes are there?
150, 000 – 450,000 per ml
whats a thrombocytes?
platelets - fragment of cytoplasm
what do thrombocytes not have?
no nucleus
cytoplasmic granules
what are thrombocytes released from?
megakaryocytes
what are platelets used for?
Platelets are cells in your blood which form clots to help stop bleeding
whats another term for red blood cells?
erythrocytes
erythrocytes are most _______
abundant
what do erythrocytes facilitate ?
They facilitate the transport of gases
what do erythrocytes not have?
they don’t have a nucleus or mitochondria
erythrocytes have a ____ ________
complex cytoskeleton
How are erythrocytes altered?
Altered by change in osmotic changes
what is Haematopoiesis?
process by which immature precursor cells develop into mature blood cells.
where does Haematopoiesis begin?
Begins in embryo
How does haematopoiesis progress through life?
active marrow decreases
pelvis, spine, ribs, cranium and proximal end of large bones remain active
What is the colour of active marrow?
Red
What is the colour of inactive marrow?
Yellow
What is the process of haematopoiesis? (1)
Mesoblastic stage – first month of embryonic life where cells are formed outside the embryo in the mesenchyme of the yolk sac
What is the process of haematopoiesis? (2)
Hepatic stage – by the 6th week
What is the process of haematopoiesis? (3)
Medullary stage – by the 5th month blood cell formation occurs in the bone marrow
What is marrow?
Marrow – primitive stem cells & committed progenitor cells are confined
What spleen and lymph nodes important?
secondary lymphoid tissue for lymphocyte development and differentiation
What do cytokines consist of that is important to haematopoisis?
colony stimulating factors, in which promotes the growth of stem cells etc.
What are cytokines produced by?
Endothelial cells, Marrow Fibroblasts, White Blood Cells
What does cytokines regulate?
Leukopoiesis, Mitosis and maturation of stem cells
Why does cytokines regulate Leukopoiesis?
to meet the needs of the body
What are interleukins?
A group of cytokines
What is a stem cell factor?
This is a cytokine having binded to a certain receptor
What is a thrombopoietin?
a class 1 hematopoietic cytokine
What does glycoprotein do?
growth and maturation of megakaryocytes
What is the relation between erythropoietin and glycoproteins?
Erythropoietin is a glycoprotein,
glycoproteins are cytokines
What is erythropoiesis?
Released in response to tissue hypoxia
Outline the process of Erythropoiesis?
We have a multipotent stem cell
Which starts off as a large nucleated erythroblast (20um)
As it matures it becomes smaller
And we are left with a Reticulocyte (immature rbc 7um)
It then leaves the bone marrow and enters circulation
Matures in circulation
Becomes a mature RBC (5 million per ul)
How much haemoglobin contain?
140-160 g/l of blood
How many copies does one red blood cell contain?
280 million
What is the most common polypeptide chain in haemoglobin?
2 x alpha
2 x beta
What does each subunit in blood contain?
haem group
each haem had a Fe atom
List the functions of blood
gases nutrients and waste products hormones Maintenance of body temperature Defence mechanisms
describe the transport of oxygen from the lungs?
oxygen is taken in from the lungs and alveoli
Oxygen is then dissolved in the plasma where it binds to haemoglobin
This results in Oxyhaemoglobin
How is oxygen transported in tissues?
in tissues there is low CO2
What the CO2 does is bind to the haemoglobin
By binding it essentially distorts the hb molecule
So that O2 becomes dissociated from hb
And then the O2 is dissolved into the plasma
How is CO2 transported back to the lungs?
There are high levels of CO2 coming out of the tissues
There are high levels of CO2 diffusing into the plasma
CO2 in the Erythrocytes become Carbonic Acid
The reaction is stimulated by Carbonic Anhydrase
Carbonic anhydrase dissociates into H+, HCO3- ions
HCO3 ions move into plasma
H+ ion is stabilised by Cl- ions entering
Chloride shift occurs, which allows transport to lungs
What does Sickle cell anaemia consist of?
Abnormal Hb (HbS)
Crystallises when deoxygenated
RBC shape altered
What are the characteristics of haemolytic anaemia?
is either hereditary or acquired
RBCs are spherical, fragile , and rupture easily
What are the characteristics of iron-deficient anaemia?
Low RBC count or low Hb content
microcytic
hypochromic
List the other types of anaemia?
Pernicious anaemia
Normocytic anaemia
Polycythaemia vera
Haemochromatosis
What percentage of WBC are Neutrophils?
50-70%
What percentage of WBC are Lymphocytes?
25-35%
What percentage of WBC are Basophils?
0.4-1%
What percentage of WBC are are Eosinophils?
1-3%
What percentage of WBC are Monocytes?
4-6%
What can cause Leukopenia?
chemotherapy Radiation autoimmune diseases spleen disease liver diseases viral infections vitamins and minerals deficiency bone marrow diseases drugs antibiotics
what can cause leukocytosis?
Anaemia
Infections
Allergy
systemic diseases
inflammatory diseases (e.g. RA)
tissue damage caused by burns
Leukaemia
- Lymphocytic
- Myelogenous
- Erythroid
physical or emotional stress
medications
pregnancy
