Blood is a specialized bodily fluid that all humans contain. It contains of four main components: white blood cells, red blood cells, platelets and blood plasma.
Plasma is the liquid component of blood in which the other components are transported in. It mostly consists of water with dissolved salt and proteins. Albumin is the main protein and it he's keep fluid from leaking out of blood vessels and into tissues and it carries hormones and certain drugs. Other proteins carried in plasma are antibodies, which defend the body from infection and illnesses. Plasma acts as a reservoir that can absorb or replenish water from/to tissues and prevents blood vessels from collapsing and clogging and helps maintain blood pressure through flowing through the blood vessels continuously. Temperature is regulated by heat being carried around the body through blood circulation.
Red blood cells, also known as erythrocytes ,carry oxygen around the body. They contain haemoglobin, which is a protein that enables the carry of oxygen and makes the blood red. Oxygen is used to produce energy through respiration and the red blood cells than carry the waste product carbon dioxide away from the tissues and towards the heart in veins. Anaemia occurs when there aren't enough red blood cells in the body and this can lead to fatigue. Polycythemia is when the red blood count is too high and therefore there is a high risk of blood clotting and heart attacks due to the blood being very thick.
White blood cells are often also called leukoyctes and there are around one white blood cell for every 600-700 red blood cells in a healthy human being. Even though they are fewer, they are larger in size and due to lacking haemoglobin they are a white colour. Their main function is to protect and defend the body against infection and there are five main types of white blood cells that do this.
Granular leucocytes:
Neutrophils help protect the body against infections by killing and ingesting bacteria and fungi and by ingesting foreign debris. They are formed from stem cells in the bone marrow and are short-lived. Together with basophils and eosinophils, which I will mention later, it forms the polymorphonuclear cell family, also known as the granular leucocytes, which are white blood cells contain granules in the cytoplasm.
Basophils participate in allergic responses. They are the least common granulocytes and contain a large quantity of cytoplasmic granules. Basophils contain anticoagulant heparin, which prevents blood from clotting too quickly. They also contain histamine, which promotes blood flow to the tissues. They have protein receptors on their cells surface that bind IgE (immunoglobulin involved in macroparasite defense and allergy) . The bound to the IgE antibody causes a selective response to these cells to environmental substances, which is what causes the allergic response.
Eosionphils kill parasites and destroy cancer cells. They are also involved in allergic responses. They combat multicellular parasites and certain infections and control the mechanisms associated with allergy and asthma. They fight viral infections, which is visible by the abundance of RNases and the fibrin removal during inflammation. New research shows that they are also involved in the antigen presentation presentation to T cells.
Nongranular leukocytes:
They are white blood cells lacking granules in their cytoplasm and they include Lymphocytes and Monocytes.
There are three main types of lymphocytes. T-cells and natural killer cells protect against viral infection and can detect and destroy some cancer cells. B cells develop in cells that produce antibodies and they help the T-cell to produce antibodies. Antigens are taken in by the macrophages through endocytosis and the carried to the helper T-cells receptor. The antigen is specific to a receptor and the helper T-cell than binds to the macrophage presenting the T-cell. This causes the T-cells to become activated and the B- cell is then activated by the already activated T-cell binding to the specific B-cell, activating it. B-cells have antibodies in their cell surface membrane. The now activated B-cell starts to divide by mitosis to form a clone of their plasma cell and the plasma cell synthesis antibodies, which then attack the antigens. Part of the activated B-cell will develop into Memory cells.
Monocytes ingest dead or damaged cells and like this defend against many infectious organisms.
When the number of white blood cells is too low, called leukopenia, infections are more likely to occur. Leukocytosis refers tot he number of white blood cells to be too high and this can indicate a disease, e.g. leukaemia or an infection.
The last component of blood are Platelets also known as thrombocytes. They are cell-like particles that are smaller than erythrocytes and leukocytes. There is a ratio of around one platelet to every 20 red blood cells. They help in the clotting process by gathering at a bleeding site and clumping together to form a plug. Fibrin fibres plug most of the wound but platelets plug the gaps and they release further substances that help promote clotting. A too low number of platelets (thromobocytopenia) causes bruising and abnormal bleeding and a too high number (thrombocythemia) can cause a stroke or heart attack by making blood clot more excessively.
Plasma is the liquid component of blood in which the other components are transported in. It mostly consists of water with dissolved salt and proteins. Albumin is the main protein and it he's keep fluid from leaking out of blood vessels and into tissues and it carries hormones and certain drugs. Other proteins carried in plasma are antibodies, which defend the body from infection and illnesses. Plasma acts as a reservoir that can absorb or replenish water from/to tissues and prevents blood vessels from collapsing and clogging and helps maintain blood pressure through flowing through the blood vessels continuously. Temperature is regulated by heat being carried around the body through blood circulation.
Red blood cells, also known as erythrocytes ,carry oxygen around the body. They contain haemoglobin, which is a protein that enables the carry of oxygen and makes the blood red. Oxygen is used to produce energy through respiration and the red blood cells than carry the waste product carbon dioxide away from the tissues and towards the heart in veins. Anaemia occurs when there aren't enough red blood cells in the body and this can lead to fatigue. Polycythemia is when the red blood count is too high and therefore there is a high risk of blood clotting and heart attacks due to the blood being very thick.
White blood cells are often also called leukoyctes and there are around one white blood cell for every 600-700 red blood cells in a healthy human being. Even though they are fewer, they are larger in size and due to lacking haemoglobin they are a white colour. Their main function is to protect and defend the body against infection and there are five main types of white blood cells that do this.
Granular leucocytes:
Neutrophils help protect the body against infections by killing and ingesting bacteria and fungi and by ingesting foreign debris. They are formed from stem cells in the bone marrow and are short-lived. Together with basophils and eosinophils, which I will mention later, it forms the polymorphonuclear cell family, also known as the granular leucocytes, which are white blood cells contain granules in the cytoplasm.
Basophils participate in allergic responses. They are the least common granulocytes and contain a large quantity of cytoplasmic granules. Basophils contain anticoagulant heparin, which prevents blood from clotting too quickly. They also contain histamine, which promotes blood flow to the tissues. They have protein receptors on their cells surface that bind IgE (immunoglobulin involved in macroparasite defense and allergy) . The bound to the IgE antibody causes a selective response to these cells to environmental substances, which is what causes the allergic response.
Eosionphils kill parasites and destroy cancer cells. They are also involved in allergic responses. They combat multicellular parasites and certain infections and control the mechanisms associated with allergy and asthma. They fight viral infections, which is visible by the abundance of RNases and the fibrin removal during inflammation. New research shows that they are also involved in the antigen presentation presentation to T cells.
Nongranular leukocytes:
They are white blood cells lacking granules in their cytoplasm and they include Lymphocytes and Monocytes.
There are three main types of lymphocytes. T-cells and natural killer cells protect against viral infection and can detect and destroy some cancer cells. B cells develop in cells that produce antibodies and they help the T-cell to produce antibodies. Antigens are taken in by the macrophages through endocytosis and the carried to the helper T-cells receptor. The antigen is specific to a receptor and the helper T-cell than binds to the macrophage presenting the T-cell. This causes the T-cells to become activated and the B- cell is then activated by the already activated T-cell binding to the specific B-cell, activating it. B-cells have antibodies in their cell surface membrane. The now activated B-cell starts to divide by mitosis to form a clone of their plasma cell and the plasma cell synthesis antibodies, which then attack the antigens. Part of the activated B-cell will develop into Memory cells.
Monocytes ingest dead or damaged cells and like this defend against many infectious organisms.
When the number of white blood cells is too low, called leukopenia, infections are more likely to occur. Leukocytosis refers tot he number of white blood cells to be too high and this can indicate a disease, e.g. leukaemia or an infection.
The last component of blood are Platelets also known as thrombocytes. They are cell-like particles that are smaller than erythrocytes and leukocytes. There is a ratio of around one platelet to every 20 red blood cells. They help in the clotting process by gathering at a bleeding site and clumping together to form a plug. Fibrin fibres plug most of the wound but platelets plug the gaps and they release further substances that help promote clotting. A too low number of platelets (thromobocytopenia) causes bruising and abnormal bleeding and a too high number (thrombocythemia) can cause a stroke or heart attack by making blood clot more excessively.