Liver | Cannabis Wiki
The liver is the largest of the body’s internal organs weighing about 1.8 kilograms in a man and one point three kilograms in a woman. It forms a right-angled triangle whose bulk is on the right side of the abdomen. Although it continues across the mid-line of the body to lie below the apex of the heart and behind the stomach on the left side it stops and lies beneath the fifth rib, and it reaches down on the right side to just below the 10th rib. This is why doctors push their fingers under the ribs on patient’s right side to check whether the liver is enlarged.
Reddish-brown in color, the liver is not only the largest internal organ and also the most complex. It is found lying in the upper abdominal cavity. It consists of eight lobes each one made up of hexagonally shaped areas called lobules which consists of a central vein surrounded by liver cells.
The whole structure is permeated by network of veins, arteries and ducts. The ducts are channels that collect bile, which is produced by liver cells, in direct it to the gallbladder, where it is stored. This is a pear-shaped sac, about 8 centimeters long that lies underneath an extension just below the ninth rib. When the gallbladder is swollen, it can sometimes be felt just below the ninth rib in a few centimeters to the left of its point.
Processes in the Liver
The functions of the liver involve the control of more than 500 chemical reactions, making the liver the most important organ of metabolism-that is, the process whereby chemicals are changed in the body these include:
The liver breaks down glucose, the form in which carbohydrates are carried in the blood, and stores it as glycogen. The process is reversed when blood glucose levels fall or there is a sudden demand for extra energy.
Disposal of Amino Acids
The liver breaks down surplus amino acids, which make up proteins and turn the ammonia that is produced in urea a constitute or constituent of urine.
Using Fat to Provide Energy
When there is insufficient carbohydrate in the diet to fill energy needs, the liver breaks down stored fat into chemicals (ketones), which are used to produce energy and heat.
Naturally produce cholesterol is essential for the production of bile and hormones such as cortisol and progesterone.
Storing Minerals and Vitamins
The liver stores sufficient minerals such as iron and copper (needed for red blood cells) and vitamin A (which is synthesizes as well as stores), B12 and deed to meet the body’s requirement for a year.
The liver breaks down old red blood cells, using some of their constituents to make bile pigments. It also manufactures prothrombin and heparin-proteins that affect blood clotting.
Sections of the Liver
Common Hepatic Duct
The common hepatic duct collects bile and channels it to the gallbladder.
Hepatic Portal Vein
The hepatic portal vein collects blood from digestive tract and delivers it to the liver cells.
The hepatic artery supplies oxygenated blood to the liver.
From the central veins blood enters the hepatic veins which drain the liver and empty it into the inferior vena cava.
Sinusoids receive oxygenated blood from the hepatic artery and nutrients from the intestines via the porta vein. Energy, oxygen and nutrients diffuse from the capillary walls into the liver cells.
The portal triad is found at each of the six corners of a lobe; consists of a branch of the hepatic artery, a branch of the hepatic portal vein in a bile duct.
Blood is detoxified as it flows along the sinusoids towards the center of the lobule. All the lobules of the liver have a central vein.
Circulation Within the Liver
The liver has its own circulation system made up of an intricate network of veins and arteries. The vein and arteries form the liver’s own circulation system, known as the hepatic portal system. The purpose of the system is to remove harmful substances from the digestive organs and deal with them before they reach the heart. It also takes some constituents of food out of the digestive tract so they can be stored for future use.
The portal vein collects blood from the digestive tract and delivers it to the liver cells for processing, with the hepatic artery branches off the aorta to supply nutrients to the liver cells. After it is circulated through the liver’s capillaries, the blood is collected by hepatic veins at the center of each lobe and passed through the main hepatic vein to the inferior vena cava, to be transported back to the heart.
The Role of Bile
Bile, which is essential for the absorption of vitamins D and E and the breakdown of fats, is produced by the liver cells and stored in the gallbladder. It consists of bile salts and bile pigments which come from the breakdown of red blood cells, cholesterol and lecithin.
The presence of fats in the stomach cause the gallbladder to contract which squeezes by all through the common bile duct and into the duodenum. Here it emulsifies fats making them easier to digest.
The liver breaks down toxic substances, such as alcohol, and harmless constituents that can be excreted from the body. It also processes chemicals produced naturally in the body, although their constituents are usually recycled. This is the reason why substance abuse can cause serious damage by overloading the liver.
In extreme cases, cirrhosis can result. This is a serious disorder in which healthy liver tissue is damaged and replaced by fibrous scar tissue, eventually hardening the whole organ. The long-term effect is that the liver’s regenerative capability is greatly reduced.