? 發問於 科學及數學生物學 · 1 十年前

What is the function of plasma?

About 55 percent of the blood in a human body is a liquid called plasma. What is the function of plasma? Please answer as detail as you can.

2 個解答

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  • 1 十年前
    最愛解答

    Plasma: is the liquid part of blood; it transports dissolved substances around the body and defends it against disease.

    Blood plasma is the liquid component of blood, in which the blood cells are suspended. Plasma is the largest single component of blood, making up about 55% of total blood volume. Serum refers to blood plasma in which clotting factors (such as fibrin) have been removed. Blood plasma contains many vital proteins including fibrinogen, globulins and human serum albumin. Sometimes blood plasma can contain viral impurities which must be extracted through viral processing.

    Plasma resembles whey in appearance (transparent with a faint straw colour). It is mainly composed of water, blood proteins, and inorganic electrolytes. It serves as transport medium for glucose, lipids, amino acids, hormones, metabolic end products, carbon dioxide and oxygen. The oxygen transport capacity and oxygen content (CaO2) of plasma is much lower than that of the hemoglobin in the red blood cells; the CaO2 will, however, increase under hyperbaric conditions.) Plasma is the storage and transport medium of clotting factors. Its protein content is necessary to maintain the oncotic pressure of the blood, which "holds" the

    Goodies in plasma:

    Please call them "useful substances".

    The Plasma contains dissolved substances. Most of these are useful and are carried to places where they are to be stored or used. The products of digestion including glucose, amino acids, mineral salts and vitamins are carried from the small intestines (ileum) to other organs. Glucose is either stored in the liver and muscles as glycogen or used in tissue respiration. Amino acids are used by all your tissues for growth and repair. The liver is able to remove excess amino acids from blood plasma and add some of those which are needed. The nitrogen from excess amino acids is turned into a harmful substance called urea.

    Vitamins are carried by plasma from the ileum to all other parts of the body. They help keep your tissues healthy. Minerals are also absorbed into blood plasma in the ileum and carried around the body. Different minerals are required for different reasons. You must know that calcium is needed for teeth and bones. It is also required for muscles. Calcium ions are involved in the chemical mechanisms of muscle contractions. So without enough calcium in your diet, your muscles are not able to contract correctly.

    Iodine is required by the thyroid gland in your neck to make a hormone called thyroxine. This controls how fast your body works. In particular, thyroxine affects the rate of tissue respiration. Hormones are secreted by endocrine glands and carried in blood plasma to target organs. Insulin is secreted by endocrine glands called "islets of Langerhans". These are small groups of cells in your pancreas. The main target organ for insulin is the liver. Insulin stimulates the liver to convert excess glucose in your blood into glycogen. Insulin is also necessary for tissue respiration.

    2006-12-13 09:23:11 補充:

    Baddies: Please call them "harmful substances".The main baddies in your blood are urea and hydrogen carbonate ions. Urea is the product of excess amino acids. It is put into blood plasma by the liver and removed by the kidney.

    2006-12-13 09:23:45 補充:

    This process is called excretion. Your kidneys also excrete excess water and salts from your body. This process is called "osmoregulation". It is under the control of the brain and involves chemical messengers ( hormones) secreted by the pituitary gland.

    2006-12-13 09:24:02 補充:

    Hydrogen carbonate ions are produced when carbon dioxide produced by tissue respiration is absorbed by blood plasma. In your lungs, hydrogen carbonate ions turn back to carbon dioxide which is excreted when you exhale.

  • Gemini
    Lv 4
    1 十年前

    The scope of this treatise is to study the therapeutic effects of magnetic power on human ailments. The magnetic force works on the human body through the circulatory system. Hence the knowledge of the functions of the blood, the heart and the circulatory system are very important for this method of treatment. Let us, therefore, note some details about them before we proceed to discuss the principles methods and technology of the magnetic treatment.

    The blood is a fluid that circulates through the heart, arteries, capillaries and veins carrying nourishment and oxygen to the tissues of the body and taking away waste matter and carbon dioxide from them.

    A. Cells

    (i) Red blood corpuscles (Erythrocytes)

    45 to 50 lacs per cubic millimeter.

    (ii) White blood corpuscles (Leucocytes)

    5,000 to 10,000 per cubic millimeter.

    (iii) Platelets (Thrombocytes)

    2 to 5 lacks per cubic millimeter.

    All these cells are very minute, remain floating about in the liquid and are visible only under the microscope.

    B. Fluid Plasma-This is comprised of the following ingredients:

    (1) Water- (90-92 per cent of total fluid),

    (2) Gases--Oxygen, carbon dioxide, nitrogen.

    (3) Foods--Carbohydrates (glucose), fat (fatty acids), Protein (amino acids).

    (4) Blood Proteins--Serum albumin, serum globulin, fibrinogen,

    (5) Salts--

    (i) Chlorides of sodium.

    (ii) Bicarbonates of calcium

    (iii) Sulphates of potassium.

    (iv) Phosphates of magnesium.

    (6) Protective substances--Agglutinin antitoxin, bacteriolysins, opsonins.

    (7) Autacoids--Internal secretions from ductless glands.

    (8) Waste--Urea, uric acid, creatinine, xanthine, hypoxanthine, gaunine, adenine, and carnine.

    The blood is a red, non-transparent, nutritive fluid and has a peculiar odour. Arterial blood is bright red or scarlet and the venous blood is dark red or crimson. It is of alkaline reaction and is salty in taste. Its specific gravity is 1050 to 1060. The body of a healthy adult contains about 5-6 liters of blood, which weighs about one-thirteenth or one-fourteenth of the total body weight.

    The red blood cells (erythrocytes) contain a protein pigment, called Hemoglobin, which provides red color to the blood. Iron is one of the main constituents of the hemoglobin. Hemoglobin readily unites with oxygen and just as readily gives it up. When blood in lungs gets saturated with oxygen, all the oxygen combines with hemoglobin of the red cells, but when the blood passes into the distant organs where oxygen has already been used up by the cells, the hemoglobin gives up its oxygen to the cells. The oxygen content in a human adult averages from 12 to 17 pet cent (12-17 grams of hemoglobin in 100 grams of blood). The red blood cells are so small that a line of 3000 of them would fall a little short of 25 mm in length. The human body contains about 25 X 1012 (25,000,000,000,000) red cells.

    The red blood cells are small disc-like bags, 8 mm in diameter, occupying 45 to 50 per cent of the total blood volume. They are flexible biconcave discoid bodies. Hemoglobin molecules occupy some 28% of volume of each red blood corpuscle.

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