LIVERThe structure of the liver: The liver is usually regarded as the most powerful organ in the body because it is constantly at work, controlling- major activities going on in the body. It is located on the right side of the upper abdomen and partly overlaps the stomach. It is basically divided into lobes.
FUNCTIONS OF THE LIVERThe liver performs a number of functions which include:
(1) Digestion: The liver produces bile which is secreted into the duodenum through the bile duct. The functions in digestion include:
(a) It adds water to chime (less watery form of food undergoing digestion, because of its high percentage of water.
(b) Its alkaline (sodium) salts neutralize hydrochloric acid of the chime, thereby providing a right medium for the action of pancreatic juice enzymes
(c) It reduces the surface tension of fats and emulsifies them i.e splits them into minute droplets
(2) Deamination: Proteins are not stored in the body and so excess amino acids must be eliminated. Amino acids which are not built up into proteins and used for growth and replacement of cells are broken down (deaminated) by the liver into carbohydrate and urea by the removal of the amino group. The urea is secreted through the kidney while the carbohydrate can be converted into glycogen to be stored or oxidized to release energy.
(3) Storage of iron: Iron derived from the broken down red blood cells (erythrocytes) is completed and stored in the liver.
(4) Regulation of blood sugar: The liver has the role in carbohydrate metabolism and so is able to convert glucose, amino acid and other substances to an insoluble carbohydrate called glycogen. Some of the glucose may be taken from the hepatic portal vein carrying blood which is rich in digested food from the small intestine to the liver. Their reserve of glycogen is converted to glucose so as to maintain the level of glucose circulating in the blood.
(5) Regulation of body temperature: Many chemical activities taking place in the liver release energy in form of heat which i distributed round the body by the circulatory system.
(6) Fat metabolism: The liver contains about 6% stored lipid and when required for use in providing energy and in starvations, it travels in the blood stream from the fat deposits, leading to a fall in fat content of the liver. This happens after exhaustion of all other body fats. Some are used directly or changed to other substances that can be oxidised for energy.
Detoxication:Poisonous compounds and other chemical substances transported in the blood to the liver are converted to harmless substances and later excreted in the urine.
(8) Manufacture of plasma proteins: The liver produces most of the protein found in blood plasma, including fibrinogen which forms an important part in the clotting action of blood.
(9) Storage of vitamins: Vitamins A and D are stored in the liver. (Livers of fish are richer in vitamins especially vitamin D than livers of mammals). The liver also stores vitamin B 12, an anti-anaemic factor which is necessary for the production of red blood cells in the bone marrow.
The liver is the heaviest organ in the body and one of the largest. It's located in the upper right portion of your belly under the ribs and is responsible for functions vital to life. The liver primarily processes nutrients from food, makes bile, removes toxins from the body and builds proteins. It's easy to see how inflammation of the liver, or hepatitis, interferes with these important functions and can lead to poor health. Fortunately, the liver is extremely resilient and most cases of liver inflammation don't even come to medical attention, but in cases of the severe liver disease, there can be a serious interruption of these essential liver functions. Let's look at each of these functions a little closer.
Processing Nutrients from Food
The digestive system immediately begins to break down the food that we eat into smaller and smaller pieces. Eventually, these nutrients will enter the blood and travel to the liver through the hepatic portal system, the major pathway that blood takes from the digestive system to the liver. The liver will then process these nutrients in different ways, depending on the body's needs. It usually stores some of the nutrients in a form that the body can use for quick energy. The rest will be used to make other important chemicals the body needs. When the liver is severely damaged, such as in liver failure, it can't continue to process nutrients from the blood that the body must have. Without aggressive medical care, the absence of these essential liver functions can result in signs of serious illness like brain damage and coma.
Bile is a thick, green-yellow fluid that the liver produces to help digest food, especially fat, as it passes from the stomach to the intestines. This fluid is made in the liver but is stored in a nearby sac called the gallbladder. When a person eats a meal heavy in fat, like a juicy steak, the body will use its store of bile to help break down the fats in the steak for digestion.
Removing Toxins From the Blood
All of the blood in the body will eventually pass through the liver. This is important because the liver needs to pull out any bad things in the blood, such as toxins, and remove them from the body. Some of these toxins are drugs, like penicillin and Tylenol, and other toxins are things that the body needs but is done with, like damaged cells, proteins and old hormones. The liver prepares all of these types of toxins to be removed from the body. However, when the liver is damaged, these toxins can't be removed and they start to accumulate creating problems.
A protein is a complex chemical that is essential to living things, like plants, animals, and people. Proteins are everywhere in the body and need to be constantly produced. The liver is in charge of building many kinds of proteins that the body uses every day. For instance, there are many proteins produced by the liver that is responsible for blood clotting. When the liver is damaged, sometimes the body isn't able to clot blood effectively. In mild cases, it just takes a long time for bleeding to stop. However, in severe cases, the blood wouldn't be able to clot. A simple cut on the skin would lead to continued bleeding (though not necessarily a dangerous amount), and possibly bruises.
HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.
1. DEVELOPMENT OF AGRICULTURE
2. IMPORTANCE OF AGRICULTURE
3. SUBSISTENCE AGRICULTURE
4. COMMERCIAL AGRICULTURE
5. PROBLEM OF AGRICULTURAL DEVELOPMENT
6. SOLUTIONS TO POOR AGRICULTURAL DEVELOPMENT
7. AGRICULTURAL LAWS AND REFORMS
8. ROLES OF GOVERNMENT IN AGRICULTURAL DEVELOPMENT
9. AGRICULTURAL POLICIES
10. PROGRAM PLANNING IN AGRICULTURE
35. WILDLIFE CONSERVATION
36. FACTORS AFFECTING LAND AVAILABILITY
39. BIOLOGICAL FACTORS
40. SOCIAL-ECONOMIC FACTORS
41. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
42. CLIMATIC FACTORS AFFECTING AGRICULTURAL PRODUCTION
47. SOLAR RADIATION
48. BIOTIC FACTOR AND AGRICULTURAL PRODUCTION
52. SOIL MICRO-ORGANISMS
53. SOIL PH
54. ROCK FORMATION
55. IGNEOUS ROCK
56. SEDIMENTARY ROCKS
58. SOIL AND ITS FORMATION
59. FACTORS OF SOIL FORMATION
60. LIVING ORGANISM
61. PARENT MATERIALS
62. SOIL FORMATION TOPOGRAPHY
63. PROCESS OF SOIL FORMATION
65. PHYSICAL WEATHERING
66. CHEMICAL WEATHERING
73. BIOLOGICAL WEATHERING
74. CHEMICAL AND BIOLOGICAL COMPOSITION OF THE SOIL
75. SOIL WATER
76. MICRO AND MACRO NUTRIENTS
77. SOIL MICRO ORGANISM
78. PROPERTIES OF SOIL
79. SOIL STRUCTURE
80. SANDY SOIL
81. CLAY SOIL
82. LOAMY SOIL
83. SOIL TEXTURE
84. IDENTIFICATION OF SOIL TYPES THROUGH EXPERIMENTS
85. RETENTION OF WATER BY VARIOUS SOIL TYPES
86. DETERMINATION OF SOIL PH REACTION
87. COLORIMETRIC DETERMINATION OF SOIL PH LEVEL
88. PH SOIL TEST
89. PLANT NUTRIENTS
90. MACRO NUTRIENTS IN GENERAL
112. THE MAINTENANCE OF SOIL FERTILITY
113. CROP ROTATION
114. APPLICATION OF ORGANIC MANURES
115. FARM YARD MANURE
116. APPLICATION OF INORGANIC MANURE
118. FARMING PRACTICES
119. BUSH BURNING
121. FERTILIZER APPLICATION
122. ORGANIC MANURING
123. FARM YARD MANURE
126. CROP ROTATION
133. FARM POWER AND MACHINERY
134. SOURCES OF FARM POWER
135. HUMAN SOURCE
142. FIELD MACHINES
164. SIMPLE FARM TOOLS
165. AGRICULTURAL MECHANIZATION
166. THE CONCEPT OF MECHANIZATION