Key difference: Both, Liver and Lungs are evolved in the purification process of the body. Livers are involved in the detoxification; whereas Lungs are involved in the gas exchange that is taking in oxygen and releasing carbon dioxide.

A liver is the largest internal organ, as well as the largest gland of a body. It is the most vital organ present in vertebrates and some other animals.  It performs many functions, and is basically responsible for the detoxification, plasma protein synthesis, and the production of biochemicals that are necessary for digestion.

The term 'liver' is derived from the Greek word ‘hepar’ or ‘hepat’.

There is one liver basically in the vertebrates and other animals. It is located at the upper right-hand portion of the abdominal cavity, beneath the diaphragm, and on top of the stomach, right kidney, and intestines. They are reddish brown organs with four lobes of unequal size and shape. During development, the liver size increases with age, on an average it grows in 5 cm span at every 5 years; the adult size is the full matured liver size. Its size depends on the age, sex, body size and shape. The human liver normally weighs 1.44–1.66 kg (3.2–3.7 lb) and is a soft, pinkish-brown, triangular organ. Lobules are the functional units of the liver. Each lobule is made up of millions of hepatic cells, which are the basically known as the metabolic cells. Lobules are the functional units of the liver. The two major types of cells, which populate the liver lobes, are the karat parenchymal and non-parenchymal cells.

Liver is responsible for the production of bile, which is an alkaline compound. The bile aids in the digestion via the emulsification of lipids. Liver's highly specialized tissues regulate a wide variety of high-volume biochemical reactions, which include the synthesis and breakdown of small and complex molecules that are necessary for normal vital functions. The liver also plays a major role in the metabolism of food and drinks and also serves the functions of glycogen storage, decomposition of red blood cells and hormone production. 

Due to the liver's variable functions, there are various types of diseases. The most common is the liver tumor; which is caused due to the uncontrolled growth of cells in the liver, and if not treated at the first stage, give rise to liver cancer. Many diseases of the liver are accompanied by jaundice, which is caused due to the increased levels of bilirubin in the system. The other common diseases are: infections such as Hepatitis A, B, C, D, E, alcohol damage, fatty liver, cirrhosis, cancer, drug damage (particularly by acetaminophen (paracetamol) and cancer drugs); and the pediatric liver diseases comprises of the: biliary atresia, alpha-1 antitrypsin deficiency, alagille syndrome, progressive familial intrahepatic cholestasis, and Langerhans cell histiocytosis. Boipsy Method and Liver Transplantation are the advised treatments associated with the major liver problems. The advanced techniques of treatment like the Artificial Liver Transplantation technique and the Radiation techniques have also been implemented for curing liver related problems.

The lungs are one of the hardest-working organs in the body. They are responsible for the breathing process of a body, which keeps any living being alive. The lungs are a network of connected tubes, which brings the oxygen from the air into the blood and nourishes the cells that make our body.

The medical terminology related to 'lungs' often begins with 'plumo' (adjectival form: pulmonary).

Human lungs are located in two cavities on either side of the heart. The trachea divides the two main bronchi that afterwards enter the roots of the lungs. The lungs are divided into sections of lobes, and contain a large system of air carrying tubes, which is called as the respiratory tree. The right lung has three sections called as the lobes, and is little larger than the left lung, which has two lobes. They are cone-shaped, sponge-like organs that fill the chest cavity and make up most of the respiratory tract. The lungs takes up almost 40% of the human body and covers the maximum area. The human lungs together weigh approximately 2.3 kilograms (5.1 lb), with the right lung weighing more than the left. The right lung is 30% larger than the left. The average length is 10 to 14 inches (25 to 35 cm) and the maximum width about 4 to 6 inches (10 to 15 cm).

The lungs are the most important organs, which keeps any living body alive. They expand and contract almost 20 times in a minute in order to supply oxygen and remove the carbon dioxide. They are the respiratory organs in the air-breathing animals, which comprises most of the tetrapods, few fish and few snails. Their principal function is to transport the oxygen from the atmosphere into the bloodstream, and release the carbon dioxide from the bloodstream into the atmosphere. In humans, the air passes either from the mouth or nose, and then travels through the nasopharynx, oropharynx, larynx, and the trachea (windpipe). The air passes down the trachea, which divides into two main bronchi. Afterwards the air reaches to the left and right lungs, where the bronchi branches progressively subdivide into a system of bronchi and bronchioles till the alveoli are reached.

According to the differences, there are different types of lungs in different animals, they are:

• Mammalian lungs
• Avian lungs
• Reptilian lungs
• Amphibian lungs
• Lungfish
• Invertebrate lungs

The most common lung associated disease is Asthma. The other common respiratory disorders are: acute bronchitis, lung cancer, pneumonia and tuberculosis. Nowadays, lung transplantation is carried out for major lung associated problems.

Comparison between Liver and Lung:

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