Biology Project. Liver. Form 7S Ho Man. The Anatomy ( 解剖結構 ) of Liver. The Anatomy of Liver. The Structure of Liver lobule. 血坑. The structure of Liver Acinus. The Functions of Liver.
Form 7S Ho Man
Liver is the largest and metabolically the most complex organ in our body. It performs the following functions:
1. It decomposes and cleanses all the toxic substances of the body;
2. It generates the bile-juice to help digestion;
3. It regulates the glucose,lipid, and protein metabolism;
4. It manufactures numbers of protein e.g. serum albumin ( the most abundant protein that presents in the blood circulation that helps to maintain the normal blood volume.)
5. It stores fat soluble vitamins, minerals and blood;
6. It is a major energy consuming organ, hence to maintain the body temperature and the weight of the body,etc.
For details, please refer to your Bio Notes (Ch.25 Homeostasis P.5).
A Healthy Liver A Fatty Liver
A Serve Fatty Liver Liver with Cirrhosis (肝硬化)
Case 1 : Alcoholic liver disease
An acute(急性)or chronic (慢性)inflammation of the liver induced by alcohol abuse.
Causes:Usually occurs after years of excessive drinking. The longer the duration of alcohol use and the larger the consumption of alcohol, the greater the probability of developing liver disease. The toxicity of ethanol also induces liver diseases.
Symptoms:Loss of Appetite(食欲), Nausea (作嘔), swollen abdomen (from enlarged liver), jaundice(黃疸), abdominal pain and tenderness, ascites (fluid collection in the abdomen),
Unintentional(非故意的) weight gain (because of the fluid collection), mental confusion, excessive thirst, dry mouth, fatigue(疲勞)final state will result in Cirrhosis (肝硬化)
Prevention:Limit alcohol consumption to moderate level.
Treatment: The objective of treatment is to discontinue alcohol, and to provide a high-carbohydrates, high-calorie diet to reduce protein breakdown in the body. Vitamins, especially B1 and folic acid(A water-soluble vitamin of the B-complex group), are associated with improvement.
Complications: bleeding esophageal varices(A bleeding condition resulting from dilated veins in the walls of the lower
part of the esophagus), portal hypertension (increased blood pressure in the portal vein caused by liver disease).
Case 2 : Hepatitis A
A inflammation of the liver cause by hepatitis A virus.
Causes:Disease is transmitted by contaminated food or water, or contact with a person ill with Hepatitis A. The Hepatitis A virus is shed (散播) in the stools(糞便) of an infected person during the incubation(潛伏期) period of 15 to 45 days before symptoms occur. Blood and secretions may also be infectious. The virus does not remain in the body after the infection has resolved. There is no carrier state.
Symptoms: jaundice, fatigue, loss of appetite, nausea and vomiting, low-grade fever, pale colored stools, dark urine, generalized itching,etc.
Prevention:Avoiding unclean food and water, thorough hand washing after using the washroom, and thorough cleansing if there is any contact with an affected person's blood, faeces, or any body fluid . A vaccine called Havrix is available and recommended for people who travel frequently or have long overseas stays.
Treatment: Rest is recommended during the acute phase of the disease when the symptoms are most severe.
Avoid alcohol and any substances that are toxic to the liver including acetaminophen (Tylenol). Hepatitis A virus never becomes a chronic infection.
No applied Complication
Case 3 : Hepatitis B
The term hepatitis refers to syndromes or diseases causing liver inflammation. 10 percent of those infected with the hepatitis B virus develop into chronic condition.
Symptoms: fatigue, malaise(不適), joint aches , rest of them are similar to the hepatitis A when it is acute, dark urine due to increased bilirubin(substances found in bile).
Causes: Viruses are transmitted via blood,ways like share needles, get tattoos(紋身) or have acupuncture(針灸) , infection from mother.The incubation period (time between infection and disease manifestation(顯露) ) for hepatitis B is two to six months.
Most damage from hepatitis B virus is caused by the body‘s response. This immune response against the infected liver cells (hepatocytes) damages the cells. The virus impairs(削弱) the liver's ability to produce prothrombin, increasing the time required for blood clotting. Liver damage also impairs the body's ability to get rid of bilirubin (a breakdown product of old
RBCs), causing jaundice and dark urine.
Prevention: Screening of all donated blood from hepatitis B carriers for blood transfusion. Previously, hepatitis B vaccine was made from human blood products, so it was not received well by the public. Now artificial vaccine is available.
Treatment: Acute hepatitis needs no treatment other than careful monitoring of liver function, by measuring serum transaminases(enzymatic conversion of amino groups) and prothrombin time.
Treatment of chronic hepatitis is geared towards reducing
inflammation, symptoms, and infectivity. Currently, trials are underway in Europe for natural interferon(干擾素) , which has fewer side effects. Liver transplantation is used to treat end-stage chronic hepatitis B liver disease.
Complications: chronic hepatitis, cirrhosis, hepatocellular carcinoma (early state of liver cancer)
Case 4 :Hepatitis C (Recently discovered)
An inflammation of the liver caused by the hepatitis C virus.
Symptoms: No significant symptoms, it is often detected during blood tests for a routine physical or other medical procedure.
Causes: Hepatitis C is the most common chronic bloodborn (through blood transfusion) infection in the United States. It is caused by a virus. Possible Causes:
received a blood transfusion prior to July 1992
have been on long term kidney dialysis
shared personal items, such as toothbrushes and razors which may have blood on them, with someone who has hepatitis C
Rest of them are similar to the Hepatitis B
Prevention: Avoid contact with blood or blood products whenever possible. Do not inject drugs of abuse, and especially do not share needles with anyone. Currently there is no vaccine for Hepatitis C.
Treatment:Interferon(干擾素)or a combination of interferon and ribavirin - Rebetron. But it initiates quite a lot of side effects. The treatment may also interfere with the production
of white blood cells and platelets, while the combination therapy (Rebetron) can cause sudden, severe anaemia(貧血) and birth defects (斑).
Complications: Hepatitis C is one of the largest causes for chronic liver disease in the US. It accounts for about 20% of acute viral hepatitis, 60 to 70 % of chronic hepatitis, and 30 %of cirrhosis, end-stage liver disease, and liver cancer.
Advices from doctor:All patients with hepatitis C should be immunized against hepatitis A. Not to take substances that toxic to liver, especially alcoholic beverages.
The upper liver is autopsied from alcoholic caused cirrhosis patients.
The lower one is autopsied from patients with Chronic Liver diseases.
They have various kind of nodular regeneration.
Case 5 : Cirrhosis
Damage of liver tissue, scarring(疤痕) of the liver (fibrosis(纖維化) ; nodular regeneration), progressive decrease in liver function.
Symptoms:Alike the others, plus blood vomiting, weight loss, small red spider-like blood vessels under the skin,etc.
Causes: Chronic liver diseases, Excessive alcohol use.
Treatment: The general principles of treatment include abstinence(禁絕) from alcohol use and high protein diet. Survival is enhanced if the patient stops drinking before the disease becomes severe.
Complications: mental confusion, liver failure. The outcome is expected to be poor in advanced cirrhosis with severe liver dysfunction -- 50% survive for 2 years.
Case 6 : Liver Cancer
A malignant(惡性的) tumor(腫瘤) of the liver
Symptoms:abdominal pain or tenderness, particularly in the right-upper quadrant
Causes: Unknown, probably related to chronic liver diseases and viral hepatitis.
Treatment:Aggressive surgery or liver transplantation may be successful in treating small or slow-growing tumors if they are diagnosed(診斷) early.
Complications: Liver failure, spread of the cancer cells.
maintain the hygiene of your living space especially the kitchen and toilet to prevent the spread of hepatitis viruses;
Ever remember to wash your hands thoroughly after going to the washroom;
Follow the nutrition pyramid, with moderate diet;
No excessive in take of alcohol;
Eat substances that facilitate the function of liver
E.g. Vitamin A - Improves our resistance to infection;
Vitamin C - Essential for the growth and repair of tissue;
Vitamin E - Powerful antioxidant
E.g. Bioflavonoids - strengthen capillary walls;
Zinc - necessary for the immune system;
Food contains these kind of substances are:
Tomatoes – contain essential antioxidant;
Oranges – rich in Vitamins, Bioflavnoids and Zinc
Carrots - good source of beta carotene
Bananas - mineral content with both vitamins C and B6 to help fight infection.
Other vegetables – providing more dietary fibre