Cells of the Blood Flashcards
What percentage of the blood is plasma?
55%
What percentage of the blood is white blood cells and platelets?
<1%
What percentage of the blood is red blood cells?
45%
What percentage of plasma is water?
91.5%
What percentage of plasma is solutes (mainly proteins)?
8.5%
What is the role of plasma?
Acts as a solvent and suspending medium for blood components
What is the average volume of blood in adults?
5 litres
What percentage of blood is formed elements?
45%
Usually >99% of formed elements are red blood cells
What percentage of solutes in plasma are proteins?
7%
Plasma is composed of 1.5% of other solutes. Give examples of what these solutes are.
Electrolytes, nutrients, gases, enzymes and waste products.
7% of the solutes in plasma are proteins. Give examples of what these proteins are.
Albumin, globulins and fibrinogen - these exert colloid osmotic pressure.
Define Haematopoeisis
Haematopoeisis is the process by which formed elements of blood develop
How are blood cells produced?
A pluripotent stem cell commits to one cell line and undergoes many cell divisions leading to clonal expansion
Which cells derive from the common myeloid progenitor?
Megakaryocytes, Erythrocytes, Mast cells, Myeloblasts
Which cells can derive from a myeloblast?
Myeloblasts give rise to white blood cells of the granulocytic series (characterized by granules in the cytoplasm, such as neutrophils, eosinophils, and basophils and monocytes)
What cell can monocytes give rise to?
Macrophages
What cell can megakaryocytes give rise to?
Thrombocytes
What cells can the common lymphoid progenitor give rise to?
Natural killer cells (large granular lymphocyte)
Small lymphocytes
What cells can small lymphocytes give rise to?
B lymphocytes
T lymphocytes
What cells can B lymphocytes give rise to?
Plasma cells
Give another name for red blood cells?
Erythrocytes
How long do erythrocytes last in the body?
120 days (due to wear and tear on plasma membranes from squeezing through capillaries)
How are erythrocytes removed from circulation?
They are removed from circulation by phagocytic macrophages in spleen and liver
What is the rate at which new mature erythrocytes enter the circulation?
2 million erythrocytes per second
How are erythrocytes adapted to their function?
1) They contain haemoglobin, an oxygen carrying protein
2) Biconcave discs, flexible structure
3) No nucleus to maximise space for oxygen transport
What stimulates erythrocyte production?
Erythropoietin (EPO)
What is release in response to hypoxia?
Erythropoietin (EPO)
What organ secretes erythropoietin into the blood?
The kidneys
How long does it take reticulocytes to mature into red blood cells?
1-2 days
What is the name of the precursor cell erythropoiesis produces in red bone marrow?
Proerythroblast
What happens near the end of the development of the proerythroblast?
It ejects its nucleus and becomes a reticulocyte
How does erythropoietin (EPO) increase red blood cell production?
It increases the rate of maturation of proerythroblasts
Where is the primary site of haematopoeisis?
Red bone marrow
Where is red bone marrow present (in adults)
In bones of axial skeleton, pectoral and pelvic girdles and proximal epiphyses of humerus and femur
What percentage of the cells in red bone marrow are pluripotent stem cells?
0.05-0.1%
As we age, what is red marrow replaced by?
Yellow marrow
Under what conditions could yellow marrow convert to red marrow?
Severe bleeding etc.
What is yellow marrow mainly made up of?
Fat
Red bone marrow is…
…high vascularised connective tissue
Where is red bone marrow present in children?
It is found in all bone, the liver and the spleen
What is the function of neutrophils?
Phagocytosis - destruction of bacteria
What do white blood cells do?
Combat pathogens and other foreign substances entering the body.
Most live for a few hours to a few days
What percentage of white blood cells are neutrophils?
60-70%
What is the function of basophils?
Intensify overall inflammatory response in allergic reactions
What percentage of white blood cells are basophils?
0.5-1%
What percentage of white blood cells are eosinophils?
2-4%
What is the function of eosinophils?
Combat effects of histamine in allergic reactions
Destroy certain parasitic worms
What is the function of monocytes?
Transform into macrophages, then phagocytosis
What percentage of white blood cells are monocytes?
3-8%
What percentage of white blood cells are lymphocytes?
20-25%
What is the function of lymphocytes?
B cells develop into plasma cells, which secrete antibodies.
T cells attack invading viruses and cancer cells
NK cells attack variety of infectious microbes
What is the lifespan of a platelet?
5 - 9 days
What is the function of platelets?
To form a platelet plug to help achieve haemostasis
Do platelets have a nucleus?
No
How many fragments do megakaryocytes split into?
2000 - 3000 fragments
Where are megakaryocytes found?
In red bone marrow
Each fragment formed from a megakaryocyte is enclosed by a piece of…
…plasma membrane
Each fragment formed from a megakaryocyte forms a…
…platelet (thrombocyte)
What is the normal range for haemoglobin concentration (Hb) in a full blood count?
- 0 - 18.0g/dL (Male)
11. 5-16.5g/dL (Female)
What is the normal range for a mean cell volume (MCV) in a full blood count?
77-95fL
What is the normal range for mean cell haemoglobin (MCH) in a full blood count?
27.0 - 32.0 pg
What is the normal range for haematocrit or packed cell volume (PCV) in a full blood count?
- 4-0.52 (Male)
0. 36-0.47 (Female)
What is the normal range for mean cell haemoglobin concentration (MCHC) in a full blood count?
32.0-36.0g/dL
What is the normal range for a red blood cell count (RCC) in a full blood count?
- 5-6.5 x10^12 (M)
3. 8-5.8 x 10^12 (F)
What is the normal range for platelets in a full blood count?
150-400 x 10^9/L
What is the normal range for White blood cells (WBC) in a full blood count?
4-11 x 10^9/L
What is the normal range for Neutrophils in a full blood count?
2.0-7.5 x 10^9/L
What is the normal range for Lymphocytes in a full blood count?
1.3-4 x 10^9/L
What is the normal range for Eosinophils in a full blood count?
0.04-0.44 x 10^9/L
What is the normal range for Monocytes in a full blood count?
0.2-0.8 x 10^9/L
What is the normal range for Basophils in a full blood count?
<0.1