Blood pressure is created by the relationship between blood flow and blood vessel resistance.
Blood is circulated by the circulatory system and delivers nutrients to and removes waste from cells.
A healthy adult has a 4-7 litre blood volume and makes up 8% of the body’s weight.
After birth, blood cells are created in red bone marrow. The production site moves from the diaphysis to the epiphysis as we age and takes on more yellow bone marrow (fat cells).
Blood production sites in adults are the long, short and flat bones. Lymphocytes are produced her and in lymphatic organs and glands. The spleen is a major blood reservoir.
Blood is made up of red blood cells 42% (formed) and plasma 58% (unformed). Red blood cells are made up of thrombocytes (blood platelets), erythrocytes (red blood cells), and leucocytes (white blood cells).
Blood plasma is fluid and contains: water 90%, protein 7-8%, electrolytes, nutrients, waste, trace elements, vitamins, hormones and enzymes.
Blood plasma and blood serum are two different things. Serum does not contain fibrinogen and is therefore not coagulable.
Blood plasma contains 5 different protein groups based on their electrical charge: albumin 60%; alpha 1, alpha 2, beta and gamma globuline.
Albumin is the smallest blood protein. It helps with homeostasis, protein stores, and transport. It plays a vital role in the kidneys, especially in the renal corpuscles which are responsible for blood filtration. When there is any illness here, albumin leaks out of the body, and can cause edema and prevent intercellular fluid from being recirculated. Globuline looks a little like a ball, and varies in size, which is why there is alpha 1, alpha 2, beta and gamma types. Alpha and beta types help with iron, fat, cortison and vitamin B12 transport. Gamma type helps with immunity and has a waste removal function. Fibrinogen and prothrombin are blood coagulators. Plasminogen dissolves blood clots. Transferrin transports iron to and from its sites (spleen, liver, red bone marrow).
Hemocytoblasts build erythrocytes, leucocytes and thrombocytes
Leucocytes build granulocytes, monocytes and lymphocytes Granulocytes consist of neutrophiles, eosinophiles and basophiles Monocytes consist of histiocytes and tissue macrophages Lymphocytes consist of T Lymphocytes and B Lymphocytes
Hemocytoblasts build red blood cells. The final result is the erythrocyte, which does not contain a cell nucleus. Blood cells can be too small when they lack iron and be too big when there is a maturation disorder. Sickle cell formation is when the cell releases its oxygen.
Erythrocytes have a life expectancy of 120 days in the blood stream. Phagocytes then come and eat them. They also live in the spleen, liver and red bone marrow. 160 million red blood cells are created every second. A normal red cell count in a human is between 4.2 and 6.2 million mm cubed.
Red blood cells contain hemoglobin, which is a mix of iron, colour and protein. When the cell is broken down, these parts are separated. Hem is further broken down into bilirubin and digested by bile. The globin is digested like a protein.
A lack of oxygen in the tissues sounds an alarm in the kidneys and erythropoetin (EPO) - a type of messenger - is sent from the kidneys to red blood cell production sites. EPO has been used in sport as a doping tool.
Leucocytes are the body’s defenders. Their job is to: eat (phagocytes), create antibodies (check incoming pathogens and mark them if any are foreigners), and also killer cells (blow up virus- and cancer-infected cells with sodium ‘dynamite’). Normal count in the body is about 4,000-9,000 mm cubed.
Most leucocytes (90%) reside in tissue and bone marrow. They use the circulatory system to get to wherever it is needed in the body. They can pass through a capillary wall by shapeshifting. They swim like an amoeba which is highly efficient and chemically listen for infection sites using their receptors.
Monocytes are big phagocytes and like eating. They live for 1-2 days in the blood and then transform into a histiocyte when they leave the blood stream and enter tissue. They signal to leucocytes that a clean up crew (anti-body) is needed.
Granulocytes are a lysosomic microphage and love eating viruses and bacteria. They have a short life expectancy, as they contain a protein digesting enzyme, which also eats the proteins that it is made up of. There are three subgroups: neutrophiles, eosinophiles and basophiles, which each react to different colours.
Neutrophiles are the most popular kind (60-70%). They are born in bone marrow, swim in the blood stream to tissue, and eat pathogens there. At first they have a rod like nucleus which matures into a segmented nucleus. When these enter the blood stream of your client, then they are only there because there is a very high risk infection.
Once the risk weakens, eosinophiles take over and prepare the person for healing. Eosinophiles make up 3%. They eat marked (by antibodies) pathogens (also known as immune complexes). When there is an increase in eosinophiles in the blood then the disease in the body is under control. They also appear in those who have allergies and parasites.
Basophiles make up 1%. They don’t eat anything. They play a role in immediate type and IgE allergies, because they contain histamin and heparin.
About 20-30% of leucocytes are lymphocytes. 70% of lymphocytes live in lymphatic organs and 26% in tissue. Lymphocytes constantly recircle from the blood to the lymph organs and back again. They have different life spans, depending on their task but they are mainly an antibody producer. They are born in the bone marrow, and then flow to the lymphatic organs Thymus (where they are stamped as T Lymphocytes) and maybe to the bursa of Fabricius (where they are stamped as B Lymphocytes). Then they move to the secondary lymphatic organs and receive their orders.
B Lymphocytes are blood plasma and memory cells. They have a special antibody (marker) on their surface. This means that when an invader attaches to the cell, the B Lymphocyte will transform into a blood plasma cell (the most important antibody producer) and multiply. B Lymphocytes have a good memory, and store info on previous invaders. But after a while, memory space will be wiped, if the invader does not come back again. If a pathogen gets smart and starts disguising itself (antigen shift), then the body can fall sick again and again, which is often the case with influenza bouts.
T Lymphocytes are killer, helper, suppressor and memory cells, and are important in cell mediated immunity. They create lymphokins, interleukines and interferons, which excite defence cells to release stronger defensive skills.
Thrombocytes are the fragmented end cells which are formed by hemocytoblasts. They have a short life span of 10 days. Thrombocytes contain platelet factors, which form a ball and help blood to stop and clot. The difference is that platelet factors are used to clot and many thrombocytes together are used to stop blood flow. Normal counts in the blood range between 150,000-300,000 mm cubed.
When there is a deviation from the norm range, then there is either a thrombocytosis or a thrombocytopenia. A thrombocytopenia is when there are not enough thrombocytes in the blood and an increased tendency of bleeding (many manifestations). A thrombocytosis is when there are too many thrombocytes in the blood and an increased risk of blood clotting or thrombosis. This can happen in an acute emergency situation (reactive kind) and an abnormal blood production in bone marrow (essential).
There are two popular blood type systems: ABO and Rhesus. Erythrocytes carry blood type.
ABO consists of blood type A, B, O, and AB. Most people are blood type A and O. The same blood types should only give/receive. If this doesn’t happen then the blood can agglutinate. This happens because each blood type has a specific antigen, which is designed to attack the other blood type.
Blood type AB is a universal recipient, it can receive blood from A, B, and O. Blood type O is a universal donor, it can give blood to A, B, and AB.
Today the terms universal donor and recipient are not important. Other methods of classifying blood are used.
The Rhesus factor is an antigen found on an erythrocyte. It helps classify with a blood type is positive or negative. If someone has the Rhesus factor then they are positive. If they don’t, they are negative. 85% of people are positive. During pregnancy, problems can occur if a mother is Rh negative and her baby Rh positive. Antibodies will be created against the foreign blood and the next time she falls pregnant, the baby will be affected. To avoid this, special injections of anti-D immunoglobulin are injected to hide the baby’s Rhesus factor.
Blood transfusions are used if blood needs to be replaced, during an operation, blood illness or accident. Usually the blood is human. Sometimes people even donate their own blood if they are about to undergo an operation.
Functions of blood are to send oxygen and nutrients to cells and to remove waste from cells. Blood also:
Acts as a messenger Maintains pH level of 7.36-7.43, otherwise enzymes may not be able to function properly and more Shares the warmth of the kidneys and liver (metabolically active organs) Sends antibodies to fight pathogens Maintains an electrolyte and water balance in the entire body Stops bleeding by clotting
When a blood vessel is damaged by internal (nicotine) or external (stabbing) force, three types of blood clotting are called into play:
Vascular response: constriction can be initiated by the brain (sympathetic system), or hormonally (adrenaline). Thrombocyte aggregation: thrombocytes collect at the endothelium site of injury and creates a temporary platelet clot (takes 1-3 mins) Blood clotting: permanent clotting takes 3-11 mins and follows a sequence of clotting factors from 1-13. The most important are 1, 2, 4, 8, 9.
Blood clotting occurs in three phases and are triggered exogenically or endogenically:
Exogenic (Extrinsic): the entire vessel wall is damaged and affects surrounding vessels. This is faster because of the danger of bleeding to death. Endogenic (Intrinsic): vessel wall is damaged by inflammation (nicotine). This is slower and takes more steps.
The phases are as follows:
Phase 1: Factors X, V and calcium change Prothrombin into Thrombin. Phase 2: Fibrinogen is changed into Fibrin. A net is weaved around the clot. Phase 3: Soluble fibrin transforms into insoluble fibrin.
Calcium is needed in blood clotting, otherwise it cannot happen.
When sending blood to a lab, you firstly need to render it non-coagulable. If there is a risk of stroke or other diseases based on clotting, then the patient needs to have their blood non-coagulated. This is done using sodium citrate, heparin, cumarine and acetylsalicyclic acid.
Sodium citrate: sodium citrate monopolises the calcium in blood, rendering it useless Heparin: prevents thrombosis, naturally occuring in the liver Cumarine: plant based, suppresses vitamin K production in the liver, as well as liver’s production of prothrombin Acetylsalicyclic acid: prevents the balling of thrombocytes
Thrombolysis is the dissolution of clots. The blood protein plasminogen floats around in the blood looking for areas where clots need to be dissolved. But first needs to be activated as plasmin.
Excessive bleeding is when blood clotting factors are missing. Best example of this is the hemophiliac, who doesn’t have factors 8 and 9. The opposite extreme of this is when too many thromboses are created, because of a lack of inhibitors such as antithrombin III.
Inflammation is the reaction or effect of an infection or cause. More precise, it is the reaction to a noxe, which is a pathogen. There are many causes of inflammation, including physical (burn), chemical (acid), mechanical (rubbing), microorganisms (virus), allergens (cat hair) and autogens (realse of tumors).
Symptoms of inflammation are always the same: redness (caused by increase in red cells), warmth (caused by metabolic activity), pain (caused by increased fluid, swelling (blood proteins leak out and mix with water), and impairment (caused by pain and edema).
Localised inflammation takes place in the connective tissue and vessel system. Parenchym can be damaged (secondary). The level of inflammation depends on how bad the stimulation is. When damage to the cell occurs, histamin is released, which makes the vessels more penetrable. Blood proteins, immune cells and plasma can leak out. Blood is thicker, less circulation occurs.
Pus is caused by pus producing streptococca and staphylocca. Demarcation is caused by the leaked blood vessels and immune cells that try to cordon off the infected area.
Inflammation reactions include:
Leucocytosis, over 9,000 mm cubed Fever Tiredness Antibody production and increased phagocytosis BSR acceleration CRP increase
What is CRP? These are blood proteins which are involved in fighting infection. They are the fastest way to diagnose an inflammation. The C-Reactive Protein accelerates and normalises faster than BSR and can therefore treat infection more effectively. HPs can also test for CRP themselves.
Things to know about CRP:
Increase 24 hours after infection Stronger the infection, more CRP available If more CRP, and no symptoms, could indicate cancer Chronic infection influences CRP, to show no increase Rheuma may also do the same CRP rise can be useful in diagnosis of Colitis ulcerosa and Morbus Crohn
Normal values of CRP
Under 5 mg/l Over 50 mg/l severe infection
If you want to examine blood you can use:
Hemogram: a) size, form, quality of cells, and b) number of erythrocytes, leucocytes, thrombocytes and reticulocytes Blood count: looks at the quantity of leucocytes, erythrocytes, thrombocytes, hemoglobin, hematocrits, MCV, MCH, and reticulocytes
White blood cell count: neutrophile granulocytes 65%, eosinophile granulocytes, basophile granulocytes, lymphocytes 25%, monocytes
When an infection breaks out, there is an increase in neutrophile granulocytes in the blood. This is an acute fighting phase. If there is a need for more soldiers, then immature neutrophile cells are created (known as a left shift). If even more soldiers are needed, then monocytes are called out for the final conquest. After the infection subsides, an increase in lymphocytes and eosinophile granulocytes are present in the blood as healing kicks in. Eosinophiles act like a clean up crew after a wild party.
When the body is hit by a viral infection, there is a loss of leucocytes known as leucopenia. When the body needs to fight a bacterial infection, there is an increase in leucocytes, known as leucocytosis.
Red blood cell count: volume of erythrocytes, hematocrits, hemoglobin, reticulocytes, MCH, MCV, MCHC. Men have more erythrocytes than women. Hemoglobin is the red pigment in blood (norm is 15 g/dl). Hematocrit is the concentration of red blood cells in the blood, usually between 40-45%. Reticulocyte is an immature red blood cell. MCV means the average number of red blood cells in the blood (norm is 90). There can be normocytic, microcytic and macrocytic quantities. MCH is the average hemoglobin content in the red blood cells (norm is 30pg). There can be normochrome, hypochrome and hyperchrome quantities. MCHC is the average hemoglobin concentration in all cellular components in the blood (norm is 33 Hb/dl).
Blood sedimentation rate: helps to explain any changes to the composition of the blood and how quickly the solids from the liquids can be separated. You can take a sample of venous blood, use sodium citrate to de-coagulate it. Then slowly tip the syringe back and forth (no shaking) and see how fast the solids separate from the liquids. Westergren values are taken as normal. An increase in red blood cells slows the blood rate and can signal an infection or illness or even use of medication. The average is 7mm after 1 hour. Viral infection shows up with average of 35mm. Bacterial infection with an average of 75mm. More than 90mm can be indication of cancer or sepsis.
Bleeding time: time that it takes to stop bleeding. Test this by making a small incision in the ear lobe or fingertip. Doesn’t tell you why the bleeding time is as it is. Reasons for abnormal bleeding time relate back to blood clotting and thrombocyte ability. Normally bleeding stops between 2-5 mins.
Quick: is the percentage of the clotting activity of the blood. Norm is 100%. 50% means only half the cells are working and will take twice as long. Quick value helps in anti-coagulant medication. WHO has a normalised ratio index they want everyone to use, but only useful if the patient will take a cumarin derivative-based anti-coagulant for the rest of their life. Norm is 1. Value of 2 means blood coagulates in double the time. 3 means triple the time. Lower than 1 means a thrombosis risk. Higher than 5 means a bleeding risk.
Blood gas: tests the gas composition of blood, such as oxygen and carbon dioxide. Good for checking lung function too.
Bone marrow: a biopsy can help with understanding blood formation disorders like leukaemia.
Anemia: is when there are not enough erythrocytes, hemoglobin or both in the blood. Different types of anemia exist, based on what causes the deficiency. For example: chronic bleeding, a deficiency (not enough necessary substances to form red blood cells), increased hemolytic function, formation disorder in the bone marrow, kidney failure which stops EPO production, and symptomatic (another illness is to blame) causes.
Types of erythroctyte: small, large, sickle, normal, and sphere shapes are all possible in the formation of red blood cells. There can be normocytic anemia (normal size but not enough cells), microcytic anemia (small size and not enough), macrocytic anemia (large size and not enough), sickle cell anemia (burst cell with no oxygen), and sphere cell anemia (instead of lens shape the cells are spherical).
Types of hemoglobin: hemoglobin content can also be different. There is normochrome anemia (normal number of hemoglobin, caused by acute bleeding), hypochrome anemia (not enough hemoglobin, common in iron deficiency), hyperchrome anemia (too much hemoglobin, common in vitamin B12 deficiency).
Anemia can be either acute or chronic: acute is caused by internal/external bleeding, and chronic by all the reasons listed above. This is more common. Symptoms of chronic anemia are: tiredness, paleness, tachycardia, difficulty breathing when exerting oneself, coldness, concentration problems, and dizziness. Can also manifest as dryness of skin, brittle nails, weak hair, cracked mouth corners, burning tongue, mucous membrane atrophy. The most common form of anemia is iron deficiency related. Typical in women. Can lead to microcytic or hypochrome anemia. Main cause is bleeding. But can also be influenced by inadequate diet, low iron intake, iron distribution disorder.
In iron deficiency anemia it is common to find low amounts of ferritin (not enough iron stored) and high amounts of transferrin (release of iron stores). There are also 3 stages of iron deficient anemia:
Prelatent: transferrin is normal-high, ferritin is low. No symptoms. Latent: transferrin is high, ferritin is low. Anemia symptoms. Manifest: transferrin very high, ferritin very low. Hemoglobin, erythrocytes and hematocrits are low.
In infection and tumor related anemia, the numbers for transferrin and ferritin are the opposite of iron deficiency anemia. Regardless of the cause, you need to boost iron levels in the body as a part of therapy. Do not take iron supplements with milk, as calcium interferes with the absorption, but rather with vitamin C.
Pernicious anemia: this is anemia caused by vitamin B12 deficiency. Vitamin B12 is created by microorganisms, so it is found in fermented plant based products. It affects cell division and leads to macrocytic anemia and hyperchrome anemia (too much hemoglobin). The causes of lack of vitamin B12 can be: low intrinsic factor which is needed to bind with B12 in its absorption through the intestinal wall; an antibody disorder which attacks intrinsic factor; an increased need because of pregnancy; a strict vegan diet; ileum changes caused by Morbus Crohn. Lack of B12 and folic acid can occur at the same time. Lack of folic acid affects nerve tissue, mucous membrane and erythrocyte cells. This is why neurological, gastrointestinal and normal anemia symptoms can show up. The lack of erythrocytes may produce light ikterus. Send your patient to a doctor to rule out stomach cancer, which can be a cause too.
Folic acid deficiency anemia: is similar to vitamin B12, because folic acid belongs to the vitamin B family. But there are no neurological symptoms. Main cause is alcoholism, poor nutrition, and digestive problems, such as sprue. When both vitamin B12 and folic acid are low, both must be supplemented.
Hemolytic anemia: this is when the erythrocytes are prematurely broken down. Instead of a 120 day life span, they live for only a few days. The disease can be acquired (infection, blood poisoning, autoantibodies) or congenital (hereditary sickle cell or spherocytic disorder). Symptoms include common anemia symptoms, as well as ikterus, spleen swelling, skull deformation (height), liver and spleen are blood production zones. Send this patient to the doctor. Diagnosis is made from urine and blood tests (increased reticulocytes and bilirubin).
Aplastic anemia: this is damage to the bone marrow. All blood cells are affected (thrombo, leuco and erythro). Unknown but could be caused by radiation, medication, poison (quicksilver), tumors, congenital or autoimmune diseases. If the erythrocytes are affected only, then there are typical anemia symptoms. If thrombocytes are also affected, then there is increased bleeding. If leucocytes are affected, then there is an increased risk of infection. Send this patient to a doctor. Some therapy involves bone marrow transplant.