Vocabulary Development: Words Associated with Human Internal Body System and Functions II
The heart is the fifth largest internal organ of the human body. It is an organ that is indispensable in the human body system. It is located within the chest, behind the chest bone, and between the two lobes of the lungs. It consists of four chambers – two atria (singular atrium) – a right atrium and left atrium; two ventricles – right ventricle and left – ventricle.
It is a muscular pumping organ which has a cone shape. The major function of the heart is to pump blood to every part of the body so as to deliver energy to every cell of the body. The pumping action of the heart is called a heartbeat. The heartbeat can be counted by feeling the pulse at the wrist. It is estimated that man has an average of 72 heartbeats per minute.
The special muscles in the heart which are called cardiac muscles enable it to pump blood continuously. Veins carry blood to the heart while arteries transport blood away from the heart. All arteries except pulmonary arteries contain oxygenated blood while all veins with the exception of pulmonary veins contain deoxygenated blood.
The liver is another vital organ of the human internal body system. The liver lies just below the diaphragm on the right side. It partly overlaps the stomach. The liver is a large organ which has two lobes. It is reddish-brown in colour. Each of the lobes is further subdivided into small lobes. The bile duct, to which the gall bladder is attached, goes from the liver to the duodenum.
The liver performs very important functions:
a. It regulates blood sugar, that is, it controls the amount of glucose in the blood, using a hormone called insulin and glycogen.
b. It regulates blood protein. Amino acids, which result from the digestion of proteins, are stored in the liver. The liver then releases the required amount of amino acids into general circulation.
c. Another function of the liver is detoxification. It converts many toxic substances into harmless forms which are excreted from the body – such substances as toxic substances produced in the large intestine, drugs and medicines, food additives and derivatives, and water and air-borne pollutants are rendered harmless. It, therefore, removes poisons from the blood.
d. Storage of blood is another function of the liver. The liver is richly supplied with blood vessels. It is the liver that regulates the amount of and pressure of blood.
e. The liver also produces bile which the gall bladder stores. The bile is transported to the duodenum through the bile duct.
f. The formation and breakdown of red blood cells is another function of the liver. It manufactures red blood cells in the foetus.
g. The liver also stores vitamins. It manufactures vitamins A, B and D.
h. Another function performed by the liver is the production of heat. The various metabolic activities of the liver generate heat which is distributed throughout the body through the circulation of blood.
Diseases of the Liver:
Certain diseases are observable when the liver cells fail to function properly. The diseases include:
1. Diabetes Mellitus – This may result in dehydration and loss of weight. It may cause exhaustion or weakness. It can even lead to blurred vision.
2. Viral Hepatitis – This may cause inflammation and destruction of the liver cells. It may lead to loss of appetite. It may also result in the yellow colouring of the eyes and urine.
3. Gall Stones
The common symptoms of liver disease include jaundice fever, high blood pressure, weakness and tiredness, enlarged and tender liver, oedema, etc
Read through the above passage carefully and look up the words and expressions that have been emphasized.