Red Blood Cells Flashcards
What are the cellular components of blood called?
Formal Elements of Blood
What are the the three formal elements of blood?
Red Blood Cells
White Blood Cells
Platelets
What is another name for Red blood cells?
Erythrocytes
What is another name for white blood cells?
Leukocytes
What are platelets essential for?
Blood clotting
What is the term used to describe the proportion of blood made up of RBC?
Haematoocrit
What is the Haematocrit in males and females?
Males - 45%
Females - 41%
Describe the centrifugal test to used to determine the haematocrit?
Blood sample in blood capillary tube
Spun around to separate heavier element of RBC
Measure
How many RBC are there in 1 micro litre of blood?
Males - 5 million
females- 4.5 million
How many red blood cells are there in the body?
25 trillion
Describe the shape and size of red blood cells?
Flattened Biconcave Disc.
7-8 micro-metre in diametre (same size as capillaries)
2 micrometre thick
What is the reason for the shape of RBC?
Optimal shape for the diffusion of gases into and out of RBC’s and therefore a key part of gas exchange
Discuss the size of RBC in relation to the size of blood capillaries?
The diameter of RBC and blood capillaries is the same and so RBC are very flexible and able to squeeze through capillaries.
RBCs are easily deformable.
What is critical component of RBC that allows for gas transfer?
Haemoglobin
How many molecules of Haemoglobin are found in a single red blood cell?
280 Million
What are the two constituent parts of Haemoglobin?
Globin - Protein part
Haem - pigment part
What does Haem contain?
Iron which carries Oxygen
What is Globin composed of?
Several polypeptide chains (haem is nestled in amongst these protein chains)
How much Haemoglobin is there per litre of blood?
150 grams per litre of blood
Do RBC contain many organelles?
No they are anucleate and obtain energy anaerobically
What % of RBC are destroyed daily and where and by what?
1% destroyed daily in the liver, spleen and bone marrow by macrophages.
Discuss the breakdown of RBC.
At end of lifespan, RBCs are phagocytosed by macrophages in spleen, liver or bone marrow.
Globin broken down into Amino Acids which are reused for protein synthesis.
Haem is broken down into iron and biliverdin.
Iron is bound to transferin and taken to red bone marrow for erythrpoeisis.
Biliverdin becomes Billrubin.
Billirubin is further broken down in liver and excreted in bile to small intestine. From there it becomes urobiligen (yellow) and is taken to kidneys for excretion. Also in small intestine urobiligen is turned into stercobilin (brown) which is excreted as faeces. This is what gives us brown hobbies.