The Liver
Section A: Describe the cause and effect of alcohol toxicity on the structure and function of the liver.
The liver is the largest internal organ and the largest gland in the body. Glands produce hormones that other parts of the body use to function. The liver is divided into two major sections; the right side is bigger while the left is smaller. Sixty percent of the liver is made up of liver cells called hepatocytes; these cells take in nutrients, destroy and remove harmful substances from the blood. The liver is important for survival, it has many functions, and according to the British Liver Trust (2007) it has over five hundred functions. Here is a brief summary of some of the functions of the liver. It processes digested food from the intestine, it controls the levels of fats, amino acids and glucose in the blood, fights infections, produces bile, breaks down food and turns it into energy as well as produces quick energy. It produces, breaks down and controls most hormones in the body, it also makes enzymes and proteins, and these are responsible for most chemical reactions in the body, British Liver Trust (2007).

There are many conditions that can affect the functions of the liver. One of these is alcohol abuse. Alcohol is developed from the fermentation of sugar by yeast. It is a drug. The liver cannot store alcohol so it breaks down the alcohol into water, carbon dioxide and fat, then processes about ninety percent of the alcohol and removes around five percent from the body through urine and sweat, Paton (2005) as cited by Sargent (2005). The liver can only deal with a certain amount of alcohol at a time, which is one unit per hour, British Liver Trust (2007). If more than that is consumed, the liver cells will have to work harder to process the alcohol. When this is more than the liver can deal with, the rest is then transfered to the rest of the organs. The liver needs water to carry out its tasks, but because alcohol makes people pass urine frequently, it dehydrates them and forces the liver to divert water from somewhere else. Drinking alcohol moderately will not affect you in anyway; according to the BBC news (2001), even studies have shown if red wine is taken sensibly it can be good for people’s health because it contains antioxidants which can help prevent heart disease. But if alcohol is taken in excess it can damage the liver.

Alcohol abuse can cause three different types of liver disease, which are, fatty liver, alcohol hepatitis and liver fibrosis/cirrhosis, Morgan and French (2006) as cited by Sargent and Clayton (2010). Fatty liver disease develops when the liver cells becomes swollen due to too much fat. A healthy liver should have a little or no fat at all. Excessive drinking will produce fat and it will start to accumulate in the liver cells. If someone already has a fatty liver and still continues to drink, then they are more likely to develop alcoholic hepatitis, this is when the liver becomes puffy, swollen and tender, British Liver Trust (2007). Fibrosis is when the liver tries to repair and protect injured tissue from further damage by producing a protein (collagen) in the liver cells but once the cells starts to produce the protein it starts making too much and this will cause scar tissue. Eventually this will cause cirrhosis of the liver. At this stage the liver will have rough bumps this is called nodules, this happens because the liver is trying to produce cells in order to keep up with the once being destroyed. The damaged liver tissue becomes hard and eventually the liver will not be able to produce healthy cells to continue doing its job, the blood flow through the liver becomes disrupted and this can finally lead to total liver failure. When this happens the liver will lose the ability to function and it will start affecting other body activities and there is a high risk of developing liver cancer, Waugh and Grant (2006).

Section B: Jaundice and pruritus are two symptoms associated with liver disease. Describe these two symptoms and explain the physiological changes that cause them.
Jaundice is when the skin and whites of the eyes changes from is normal colour to yellow; this happens when there is too much bilirubin in the blood. Bilirubin is what is produced when an iron containing protein in red blood cells that transport oxygen (haemoglobin) is broken down and mixed in the liver so it will be easy to get rid of it, this is what gives bile (a liquid made in the liver used for food digestion) its colour. If too much haemoglobin is broken down, the liver will not be able to deal with it, Waugh and Grant (2006). The body gets rid of bilirubin when people go to the toilet (through stool and urine) but if for some reason it is not able to do so it will store in the body and will end up causing jaundice.

There are different types of jaundice cause by different reasons. Haemolytic jaundice happens when there is too much red blood cells being broken down a lot of bilirubin will be produced and the liver will not be able to cope, Peate (2008). Obstructive jaundice happens when there is a blockage to the flow of bile when it’s going into the small intestine (duodenum), this can occur due to various reasons but one of this reason is because of a gallstone. Gallstone is formed from cholesterol (fat) and other things in the bile. If the flow is block then there will be no bilirubin in the stool and it will be light in colour instead of the normal brown, the urine will also change to dark or brownish colour. There will be no bile going into the intestine which means fat will not be digested and there won’t be nutrients for the body to use. Hepatocellular jaundice happens when the liver has been damaged, for example, by alcohol abuse, which means the liver cells will not be able to remove bilirubin from the blood as it is not broken down, Waugh and Grant (2006). It doesn’t matter which type of jaundice it is, there will still be an increase of bilirubin in the blood.
Pruritus is itching; this is associated with obstructive jaundice and too much bilirubin in the blood stream. Itching occurs because the bile salt irritates the skin, Peate (2008).