Lecture five- blood cells Flashcards
How many litres of blood does the average human have
5litres
Brief overview of what blood is made up of
- blood cells (45-55%)
- plasma- blood without cell components
- human plasma proteome (proteins like albumin, immunoglobin and clotting factors)
- serum (plasma without clotting factors and fibrinogen)
Separation of blood components. Explain how you would do this and what the sample would look like in the centrifuge tube.
- take sample
- spin it in the centrifuge tube
- the blood will split into two major components
- the lower level= haematocrit composed of blood cells
- upper level= plasma
- small layer between these containing platelets and white blood cells (lymphocytes)
What is plasma
blood without the cell components.
What can plasma be used for?
As a blood substitute. When blood isn’t available. To increase volume of blood during a surgery or after trauma. This controls bleeding and aids wound healing.
Many drugs will bind to ………. proteins. What does this do? How does this explain why less than 1% of drug is active?
bind to plasma proteins which supresses the drug. Only 1% of the drug is unbound and therefore active.
What is serum?
Plasma without the clotting factors and fibrinogen.
What are some uses of serum?
- extracted from blood to do diagnostic measurements.
- used in cosmetics
- used as growth media for cell culture
The three main types of blood cells. Name them
Erythrocytes (red blood cells), Leucocytes (white blood cells) and Platelets.
Role of Erythrocytes/ red blood cells
- carry oxygen around the body
- pH buffering of the blood- keep blood within the normal range of 7.2-7.4
Describe the structure and shape of Erythrocytes
- no nucleus- cannot grow, divide or form proteins
- contain haemoglobin- O2 binds to this and is carried around the body.
- biconcave shape- high surface area to volume ration. The shape of red blood cells can also distort/fold.
What is responsible for a person’s blood type?
The polysaccharides/ proteins on the surface membrane of red blood cells.
Name the process which produces red blood cells/ Erythrocytes
- Erythropoiesis.
Describe Erythropoiesis
- controlled by the hormone erythropoietin.
- EPO is secreted in small amounts by the kidney.
- If O2 levels are low, EPO production is triggered.
- More EPO= more red blood cells = more O2 can be carried around the body
Reasons for low O2 levels=
- high altitude
- lung disease- insufficient gas exchange
- insufficient pumping of heart
- Anaemia = decrease in the number of erythrocytes/ decreased concentration of haemoglobin per erythrocyte. This can be caused by low iron/B12 and genetic disorders like sickle cell anaemia.
What are platelets
- cell fragments with no nucleus
- involved in blood clotting
- derived from megakaryocytes
- production of platelets is controlled by thrombopoietin hormone produced by the liver.
Explain how thrombopoietin hormone controls platelet production
- protein binds to the platelet.
- if the platelet counts are normal, the TBO will bind to lots of platelets so the free TPO levels are low
- BUT if the platelet count is low then free TPO levels will be high in the serum as less are bound to platelets.
- High TPO level= platelet production is stimulated.