introduction to blood Flashcards
(44 cards)
what is the average circulating volume in a typical adult male
and is it more of less in women
5L of blood in total
(broken down)
1L in the lungs
3L in the
tends to be less in women
what percentage of blood count for our total body weight?
7-8%
describe the composition of the plasma
95% is water and the remaining consists of ions and nutrients
composition kept within strict limits
(homeostasis)
what is the role of the plasma
transports biologically active compounds
Name the plasma proteins
Albumin (most abundant- makes 60% of plasma proteins)
Globulin (alpha beta and gamma)
Fibrinogen
what is the role of an albumin plasma protein
create oncotic pressure & transports steroid hormones.
explain colloid oncotic pressure
plasma proteins do not cross capillary wall therefore the presence of plasma proteins displaces water in the Intersititial space
This generates a force which drives water sodium and glucose into the blood vessel (plasma)
this movement causes the concentration of the fluid to remain unchanged but the volume is altered
why doesn’t the blood vessel burst in oncotic pressure
due to the water balancing itself out
volume changes (as Na and glucose enter blood vessel)
but water conc remains the same
terms to describe abnormally low levels of plasma proteins
hypoproteinaeima
this also leads to oedema (loss in oncotic pressure)
where do all blood cells found in the circulation come from?
undifferentiated cells called pluripotent hematopoietic stem cells from the bone marrow
what is the normal lifespan of RBC
RBC- pluripotent stem cells become a committed proginator cell
these cells have a mitochondria and ribosome but by the time it gets to the erythroblast stage it looses its ability to synthesis proteins& by the time its a full erythrocyte it has no ribosome or mitochondria
between the erythroblast cell and erythrocyte we have a reticulocyte which are almost mature red blood cells that later mature into erythrocytes after 24hrs
120 day lifespan and after this they become deformed & recycled into new blood cells
describe the function of red blood cells
carry oxygen around the body
Describe the function of erythropoietin, where it is synthesised and the factors
erythropoietin stimulates the progression of
pluripotent cells becoming imature erythroblast cells
factors such as anemia and liver disease cause increase in erythropoietin
give examples of what leukocyte/white blood cells are divided into?
Granulocytes
Agranulocytes
give examples of granulocytes
neutrophils (most abundant)
eosinophils
basophils
give examples of types of agranulocytes
monocytes
lymphocytes
what are lymphocytes divded into ?
B cells and T cells( T helper & T killer cells)
what is the difference between a monocyte and a macrophage
monocytes circulate in the plasma
macrophages are not in the circulation
understand the factors controlling white blood cell formation
more complex that erythropoeisis as u have more cells to consider
it is controlled by a cocktail of different cytokines,colony stimulating factors + interleukins that create the conditions to stimulate one particular WBC to mature
in response to infection what does an increase in neutrophils and increase in lymphocytes increase?
viral infection = increase in lymphocyte number
bacterial = neutrophils increase
Define what is meant by haematocrit
(common measurement of blood )
it is a measurement of red blood cell volume (compared to whole blood)
State the normal value for haematocrit and appreciate how this may change in certain circumstances
normal range 40-50%
may be different less in women
increase in dehydration and erythpoeisis
state a factor that affects viscosity
increase temp decreases viscosity & vice versa
what volume of blood does a newborn have?
350ml
