Yasir Munshi Unit 20A 19219502
Unit 20: Biomedical Science
Learning Aim A: Understand the principles of haematology
and its use in medical diagnosis Assignment
Composition of human blood
Haemato means “blood”, so haematology refers to the study of blood, blood-forming
tissues and blood diseases. Haematology is significant in biomedical science because
blood circulates throughout the entire body and gives diagnostic clues about the overall
health status of different organs in the body.
Tests performed in haematology give information about oxygen transport, infection,
inflammation, correct production of blood cells in bone marrow, proper blood clotting
ability and infections transmitted in the blood. Biomedical scientists use haematology
tests to support screening, diagnosis, disease progression evaluation, treatment and
management of diseases.
Blood samples from patients admitted to hospitals or from diagnostic laboratories are
tested using automated equipment, microscopy and specialist tests. The data generated
is analysed by biomedical scientists, doctors, nurses and other health care professionals.
According to Unit 20 of the BTEC specification, biomedical science tests support health
care practitioners in carrying out screening, diagnosis, disease progress evaluation and
management/treatment of diseases.
Blood is a special type of connective tissue. Blood is made up of two main components:
plasma and formed elements. Plasma is the liquid component of the blood, while the
formed elements consist of erythrocytes, leucocytes and thrombocytes. Erythrocytes
refer to red blood cells, leucocytes refer to white blood cells and thrombocytes refer to
platelets. Every formed element has a structure suitable for its function. An alteration in
the structure, function or number of the formed elements may indicate disease.
Principle behind diagnostics in
haematology
Diagnosis in haematology depends on the analysis of blood results compared with
reference ranges for each blood component. An abnormality in the number, morphology
or function of blood elements may suggest the presence of disease. For example, a
,Yasir Munshi Unit 20A 19219502
reduced amount of haemoglobin indicates anaemia, while abnormalities in the white
blood cells may indicate infection, inflammation or leukaemia. Reduced numbers of
thrombocytes may indicate problems with blood clotting ability.
In this report, I will first look at the morphology and function of the main blood
components. Then, the effect of two diseases on the composition of the blood will be
discussed. These diseases are iron deficiency anaemia and leukaemia. These diseases
were chosen because they affect the blood in different ways. Iron deficiency anaemia
mainly affects the erythrocytes and haemoglobin, while leukaemia mainly affects the
leucocytes and the process of bone marrow production. This makes it easier to compare
a red blood cell disorder with a white blood cell/bone marrow disorder.
This report will also involve carrying out diagnostic testing on blood using a blood smear
test. The blood smear test will allow observation of the morphology of blood
components. This includes erythrocytes, leucocytes and thrombocytes, as well as any
abnormalities.
Finally, this report will evaluate haematology diagnostic techniques, including full blood
count, red blood cell count, thrombocyte count, mean corpuscular volume, mean
corpuscular haemoglobin, haemoglobin testing, ferritin and iron studies, blood film
microscopy, coagulation testing, blood grouping, bone marrow biopsy, flow cytometry
and genetic testing. This relates to BTEC Learning Aim A because it includes the
components of blood, changes in the components of blood and haematology tests.
A.P1: Explain the structure and
function of the main components of
blood
Blood can be described as being made up of plasma and formed elements. Formed
elements consist of erythrocytes, leucocytes and thrombocytes. Serum is also important
in biomedical science because it refers to the non-cellular component of blood after
clotting has occurred. Each formed element has a specific shape and function. Changes
in the structure or composition of blood components offer valuable information for
haematology diagnostics.
,Yasir Munshi Unit 20A 19219502
Erythrocytes
Erythrocytes are also referred to as red blood cells. They are involved in transporting
oxygen from the lungs to body tissues and some carbon dioxide back to the lungs. They
are the most numerous formed elements in blood and are highly adapted for oxygen
transport.
Erythrocytes have a biconcave shape, meaning that they have an indentation in the
middle with an outer border, making their middle section thinner than the sides. This
gives erythrocytes a high surface area to volume ratio. They also have a short diffusion
distance, which makes oxygen uptake and release easier.
Developing erythrocytes have nuclei, but mature erythrocytes lose their nuclei and
organelles when they reach maturity. This is an advantage because mature erythrocytes
have more space to accommodate haemoglobin molecules, which allow oxygen
transport. The absence of mitochondria means that they do not use the oxygen they
transport. Erythrocytes depend on anaerobic glycolysis for their metabolic activities.
Erythrocytes contain large amounts of haemoglobin. Haemoglobin is made up of four
polypeptide chains, each having a haem group. The haem group is an organic substance
made of a porphyrin ring attached to one ferrous iron ion, Fe2+. Binding of oxygen
molecules to the Fe2+ ions leads to the formation of oxyhaemoglobin, while the
separation of the oxygen molecules forms deoxyhaemoglobin. Oxyhaemoglobin allows
oxygen transport.
Erythrocytes are very flexible, which enables them to move through tiny blood vessels,
including capillaries, which can be smaller than the erythrocytes themselves. This is
significant because oxygen exchange takes place at capillaries and the erythrocytes
must be near the tissues to deliver oxygen.
The lifespan of erythrocytes is approximately 120 days. They are engulfed and destroyed
in the spleen and liver when they become old and worn out. Iron in the haemoglobin is
reused for the production of new erythrocytes in bone marrow.
Erythrocytes play a significant role in the diagnosis of diseases such as anaemia,
microcytic anaemia such as iron deficiency anaemia and thalassaemia, macrocytic
anaemia such as vitamin B12 and folate deficiency anaemia, and sickle cell disease.
Their significance in diagnosis comes from alterations in their quantity, morphology
and/or function.
, Yasir Munshi Unit 20A 19219502
Observations from the blood smear test
The red cells appeared abundant and small in size. They had circular appearances. They
appeared pink, red or light purple in colour depending on the intensity of the stain used.
In the places where the blood smear appeared thin, the cells had biconcave or doughnut-
shaped structures. A few of the cells seemed to appear clustered or distorted, probably
due to cell damage. Haemolysis can possibly cause distortion in the shape of cells, but
this cannot be verified without further analysis.
Leucocytes
Leucocytes, or white blood cells, have the role of defending the body against infections.
Unlike erythrocytes, leucocytes are nucleated cells with other cellular organelles such as
mitochondria and lysosomes. Leucocytes are not red because they lack haemoglobin.
They are lower in number compared with erythrocytes, but they play a crucial role in
maintaining life. Leucocytes can leave the blood vessel and move to body tissues where
they destroy invading pathogens. Some leucocytes mature and are activated outside the
blood vessels. These leucocytes mature and become activated in lymphoid tissues such
as lymph nodes, spleen and thymus.
Leucocytes can be classified into five groups: neutrophils, lymphocytes, monocytes,
eosinophils and basophils.
Neutrophils are the most abundant leucocytes. They are among the first immune cells to
fight and eliminate invading pathogens. This happens through the process of
phagocytosis, where the white blood cell engulfs the pathogen and breaks it down.
Neutrophils play an important role in acute inflammation, so elevated neutrophil levels
may suggest inflammation or infection. Neutrophilia may also indicate stress.
The next class of leucocytes includes the lymphocytes. B lymphocytes manufacture
antibodies which selectively bind to foreign antigens to neutralise them and help remove
them. T lymphocytes control the processes of the immune system and can also kill
infected or abnormal cells. Lymphocytes are involved in viral infections, AIDS, leukaemia,
lymphoma and immunity.
Monocytes leave the circulatory system and transform into macrophages in the body
tissues. They are able to phagocytose particles and also stimulate other leucocytes by
presenting antigens to them. Eosinophils take part in allergic reactions and help defend
Unit 20: Biomedical Science
Learning Aim A: Understand the principles of haematology
and its use in medical diagnosis Assignment
Composition of human blood
Haemato means “blood”, so haematology refers to the study of blood, blood-forming
tissues and blood diseases. Haematology is significant in biomedical science because
blood circulates throughout the entire body and gives diagnostic clues about the overall
health status of different organs in the body.
Tests performed in haematology give information about oxygen transport, infection,
inflammation, correct production of blood cells in bone marrow, proper blood clotting
ability and infections transmitted in the blood. Biomedical scientists use haematology
tests to support screening, diagnosis, disease progression evaluation, treatment and
management of diseases.
Blood samples from patients admitted to hospitals or from diagnostic laboratories are
tested using automated equipment, microscopy and specialist tests. The data generated
is analysed by biomedical scientists, doctors, nurses and other health care professionals.
According to Unit 20 of the BTEC specification, biomedical science tests support health
care practitioners in carrying out screening, diagnosis, disease progress evaluation and
management/treatment of diseases.
Blood is a special type of connective tissue. Blood is made up of two main components:
plasma and formed elements. Plasma is the liquid component of the blood, while the
formed elements consist of erythrocytes, leucocytes and thrombocytes. Erythrocytes
refer to red blood cells, leucocytes refer to white blood cells and thrombocytes refer to
platelets. Every formed element has a structure suitable for its function. An alteration in
the structure, function or number of the formed elements may indicate disease.
Principle behind diagnostics in
haematology
Diagnosis in haematology depends on the analysis of blood results compared with
reference ranges for each blood component. An abnormality in the number, morphology
or function of blood elements may suggest the presence of disease. For example, a
,Yasir Munshi Unit 20A 19219502
reduced amount of haemoglobin indicates anaemia, while abnormalities in the white
blood cells may indicate infection, inflammation or leukaemia. Reduced numbers of
thrombocytes may indicate problems with blood clotting ability.
In this report, I will first look at the morphology and function of the main blood
components. Then, the effect of two diseases on the composition of the blood will be
discussed. These diseases are iron deficiency anaemia and leukaemia. These diseases
were chosen because they affect the blood in different ways. Iron deficiency anaemia
mainly affects the erythrocytes and haemoglobin, while leukaemia mainly affects the
leucocytes and the process of bone marrow production. This makes it easier to compare
a red blood cell disorder with a white blood cell/bone marrow disorder.
This report will also involve carrying out diagnostic testing on blood using a blood smear
test. The blood smear test will allow observation of the morphology of blood
components. This includes erythrocytes, leucocytes and thrombocytes, as well as any
abnormalities.
Finally, this report will evaluate haematology diagnostic techniques, including full blood
count, red blood cell count, thrombocyte count, mean corpuscular volume, mean
corpuscular haemoglobin, haemoglobin testing, ferritin and iron studies, blood film
microscopy, coagulation testing, blood grouping, bone marrow biopsy, flow cytometry
and genetic testing. This relates to BTEC Learning Aim A because it includes the
components of blood, changes in the components of blood and haematology tests.
A.P1: Explain the structure and
function of the main components of
blood
Blood can be described as being made up of plasma and formed elements. Formed
elements consist of erythrocytes, leucocytes and thrombocytes. Serum is also important
in biomedical science because it refers to the non-cellular component of blood after
clotting has occurred. Each formed element has a specific shape and function. Changes
in the structure or composition of blood components offer valuable information for
haematology diagnostics.
,Yasir Munshi Unit 20A 19219502
Erythrocytes
Erythrocytes are also referred to as red blood cells. They are involved in transporting
oxygen from the lungs to body tissues and some carbon dioxide back to the lungs. They
are the most numerous formed elements in blood and are highly adapted for oxygen
transport.
Erythrocytes have a biconcave shape, meaning that they have an indentation in the
middle with an outer border, making their middle section thinner than the sides. This
gives erythrocytes a high surface area to volume ratio. They also have a short diffusion
distance, which makes oxygen uptake and release easier.
Developing erythrocytes have nuclei, but mature erythrocytes lose their nuclei and
organelles when they reach maturity. This is an advantage because mature erythrocytes
have more space to accommodate haemoglobin molecules, which allow oxygen
transport. The absence of mitochondria means that they do not use the oxygen they
transport. Erythrocytes depend on anaerobic glycolysis for their metabolic activities.
Erythrocytes contain large amounts of haemoglobin. Haemoglobin is made up of four
polypeptide chains, each having a haem group. The haem group is an organic substance
made of a porphyrin ring attached to one ferrous iron ion, Fe2+. Binding of oxygen
molecules to the Fe2+ ions leads to the formation of oxyhaemoglobin, while the
separation of the oxygen molecules forms deoxyhaemoglobin. Oxyhaemoglobin allows
oxygen transport.
Erythrocytes are very flexible, which enables them to move through tiny blood vessels,
including capillaries, which can be smaller than the erythrocytes themselves. This is
significant because oxygen exchange takes place at capillaries and the erythrocytes
must be near the tissues to deliver oxygen.
The lifespan of erythrocytes is approximately 120 days. They are engulfed and destroyed
in the spleen and liver when they become old and worn out. Iron in the haemoglobin is
reused for the production of new erythrocytes in bone marrow.
Erythrocytes play a significant role in the diagnosis of diseases such as anaemia,
microcytic anaemia such as iron deficiency anaemia and thalassaemia, macrocytic
anaemia such as vitamin B12 and folate deficiency anaemia, and sickle cell disease.
Their significance in diagnosis comes from alterations in their quantity, morphology
and/or function.
, Yasir Munshi Unit 20A 19219502
Observations from the blood smear test
The red cells appeared abundant and small in size. They had circular appearances. They
appeared pink, red or light purple in colour depending on the intensity of the stain used.
In the places where the blood smear appeared thin, the cells had biconcave or doughnut-
shaped structures. A few of the cells seemed to appear clustered or distorted, probably
due to cell damage. Haemolysis can possibly cause distortion in the shape of cells, but
this cannot be verified without further analysis.
Leucocytes
Leucocytes, or white blood cells, have the role of defending the body against infections.
Unlike erythrocytes, leucocytes are nucleated cells with other cellular organelles such as
mitochondria and lysosomes. Leucocytes are not red because they lack haemoglobin.
They are lower in number compared with erythrocytes, but they play a crucial role in
maintaining life. Leucocytes can leave the blood vessel and move to body tissues where
they destroy invading pathogens. Some leucocytes mature and are activated outside the
blood vessels. These leucocytes mature and become activated in lymphoid tissues such
as lymph nodes, spleen and thymus.
Leucocytes can be classified into five groups: neutrophils, lymphocytes, monocytes,
eosinophils and basophils.
Neutrophils are the most abundant leucocytes. They are among the first immune cells to
fight and eliminate invading pathogens. This happens through the process of
phagocytosis, where the white blood cell engulfs the pathogen and breaks it down.
Neutrophils play an important role in acute inflammation, so elevated neutrophil levels
may suggest inflammation or infection. Neutrophilia may also indicate stress.
The next class of leucocytes includes the lymphocytes. B lymphocytes manufacture
antibodies which selectively bind to foreign antigens to neutralise them and help remove
them. T lymphocytes control the processes of the immune system and can also kill
infected or abnormal cells. Lymphocytes are involved in viral infections, AIDS, leukaemia,
lymphoma and immunity.
Monocytes leave the circulatory system and transform into macrophages in the body
tissues. They are able to phagocytose particles and also stimulate other leucocytes by
presenting antigens to them. Eosinophils take part in allergic reactions and help defend
