THE LIVER

The liver is one of the vital organs in the body of a mammal. It's average weight is about 1.25kg. The liver lies below the diaphragm and is located on the right side of the abdomen. It partly overlaps or covers the stomach. The liver is dark-red in colour and is divided into smaller lobes.

The gall bladder which stores the bile is connected to the duodenum by a short tube called bile duct. The liver secretes the bile responsible for the emulsification of fat. The liver is able to control major metabolic activities within the body.

FUNCTIONS OF THE LIVER

The liver performs the following functions in the body:

Regulation of blood sugar:

The liver is capable of converting excess glucose into glycogen (animal starch) under the influence of a hormone called insulin.

Detoxification:

The liver converts poisonous and toxic materials such as drugs, alcohol e.t.c. into harmless substances which are later excreted.

Production of bile:

The liver produces or synthesises bile which aids the emulsification of fats, thereby enhancing digestion and absorption. The gall bladder stores the bile.

Formation of red blood cells:

In the foetus (embryo), the liver forms red blood cells (erythrocytes), but in adults, the marrow of the long bones forms red blood cells.

Regulation of lipids:

The liver removes lipids from the blood, converts them to glucose and oxidises them to release energy during aerobic respiration.

Breakdown of red blood cells:

The liver breaks down worn-out red blood cells (erythrocytes) in adults.

Production of heat:

The activities of the liver generate heat which helps to maintain body temperature.

Manufacture of essential proteins:

The liver manufactures essential blood proteins like fibrinogen, prothrombin, globulins e.t.c., which play important roles in blood clotting.

DISEASES OF THE LIVER

Certain diseases which can impair the functioning of the liver include:

1. Diabetes Mellitus

This disease is caused as a result of the inability of the liver cells to convert excess glucose in the blood to glycogen. This occurs due to the failure of the pancreas to produce insulin.

Effects of Diabetes Mellitus

i. Continuous dehydration

ii. Exhaustion or muscular weakness

iii. Blurred vision

iv. Loss of weight

Remedy

i. Drugs like Diabinese should be used.

ii. Regular doses of insulin injection intravenously throughout life.

iii. Avoid carbohydrate-rich foods.

2. Infective Hepatitis

This is the inflammation of the liver which may be due to viral infection or toxic substances like poison and drugs.

Effects of Infective Hepatitis

i. Loss of appetite

ii. Severe headache and nausea

iii. Yellow colouring of the eyes and urine

iv. General weakness of the body

Remedy

i. Drugs must be administered.

ii. Patient should be placed on special diet.

iii. After treatment, alcoholic drinks must be avoided.

3. Gall Stones

Gall stones are hard objects formed in the bile duct which block the passage of bile. This condition is caused by precipitation of cholesterol in the gall bladder or bile duct.

Effects of Gall Stones

i. Yellowing of the skin and eyes

ii. Inability to digest fats and oil properly

iii. General weakness of the body

Remedy

i. Drugs must be effectively administered.

ii. Stones may be dissolved by oral feeding on bile acid.

iii. Surgical operation can be performed to remove the stones.

4. Cancer of the Liver

This is a condition that leads to the uncontrollable growth or swelling of cells which do not retain the normal function of the tissue in which they arise.

Effects of Cancer of the Liver

i. General weakness of the body

ii. Exhaustion

iii. Death

Remedy

i. Surgery if detected early

ii. Radiation (radiology) or chemotherapy

iii. Liver transplant

5. Cirrhosis of the Liver

This is a serious liver disease in which damaged liver cells are replaced by dead and useless fibrous tissue. It may be caused by excessive alcohol intake over a long period or by hepatitis.

Effects of Cirrhosis

i. General weakness of the body

ii. Loss of appetite

iii. Death

Remedy

i. Avoid alcoholic drinks

ii. Surgery

iii. Liver transplant

REGULATION OF BLOOD PROTEIN BY THE LIVER

The body cells cannot store excess amino acids. The liver therefore deaminates excess amino acids.

Deamination

Deamination is the process by which excess amino acids are split into two components:

Amino group (RNH₂)

Carboxyl group (COOH)

The amino group, which is poisonous and toxic, is converted into harmless urea and excreted. The carboxyl group is processed into carbohydrates and stored in the liver as glycogen.

GAS LAW

This lesson includes:

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