Organs

Heart

A simple answer to "What is heart" is that it is the main organ of our body's circulatory system, pumping blood throughout the body. It is a muscular pump which contracts at regular intervals in order to squeeze the blood through it into the blood vessels. There are four chambers in the heart. The right chambers contain unclean, that is deoxygenated, blood. On the other hand, the left chambers contain clean, that is oxygenated, blood.

The heart is made up of connective tissue and cardiac muscle. The latter is a type of involuntary muscle, that is, it contracts and relaxes on its own without the application of force by us. Our heart is a delicate organ which is protected by the rib cage.

Brain

Made up of about 100 billion neurons and contributing nearly 2% of body-weight, brain is the supreme structural and functional unit and control center of the body and the superior-most region of CNS (Central Nervous System). Broadly speaking, major part of the brain is comprised of the hemispheres (left & right) of cerebral cortex. Cerebellum, the horizontally furrowed structure of brain's rear part, is located behind brainstem that is attached to cerebrum.

Primary components and associated structures of brain work in coordination with one another and execute a number of vital functions, viz. growth, maintenance, reproduction, sexual maturity, alarming and responding to environmental hazards, and personal & behavioral developments.

Like other structures of the body, the master organ is also vulnerable to a number of disorders, injuries, damages and severe ailments that can lead to the immediate death of the victim. Meningitis, encephalitis, concussion, intracerebral hemorrhage, brain tumor, hydrocephalus, and hemorrhage stroke are some of the major conditions that can be addressed through various available and successful treatment measures.

Lungs

Lungs are the major organ of our respiratory system, helping us obtain oxygen and get rid of carbon dioxide. Our chest cavity houses a pair of lungs which open to the external environment through the nose and mouth. A cylindrical tube, called trachea, is the main link between the lungs and the nose and mouth. When we breathe in, air travels through the trachea to our lungs.

As the trachea moves down the chest, it splits into two branches called bronchus, one for each lung. Each bronchus then further subdivides into several smaller tubes called bronchioles. Thus, each lung contains many bronchioles spread all over its structure in order to ensure an even distribution of oxygen in the lungs.

For oxygen to be able to reach all the parts of our body, it has to be dissolved into the blood. The blood stream then distributes oxygen to the entire body. Therefore, there has to be a supply of blood vessels in the lungs. These blood vessels are present on minute, sac-like structures called alveoli found at the end of bronchioles. There are numerous alveoli in each lung in order to provide the maximum surface area for the exchange of oxygen as well as carbon dioxide between the lungs and the blood stream.

Liver

Although skin is considered to be the largest organ of the human body, liver is known to be the largest internal organ and the largest gland in the human body. One may wonder about "What is a liver?" and what a purpose it serves. Being a glandular structure, it is an organized group of cells or tissues specialized to secrete or excrete certain substances to be used elsewhere in the body. Glands are broadly classified into two major groups i.e. endocrine and exocrine glands. A normal liver weighs about 1.2 to 1.5 kg and performs both endocrine and exocrine functions.

Liver is located in the right upper quadrant of the abdomen, just beneath the right side of the diaphragm and under the right lower rib cage. Concerning human liver anatomy, it has two major lobes, a larger right lobe and a smaller left lobe that are further subdivided into eight functional segments. Within a minute approximately 1500ml of blood flows through the liver to ensure its efficiency. In part due to its ample blood supply liver is a prime site for metastatic spread of cancer.

Kidneys

There are two bean shaped kidneys in the human body. A normal kidney is about 2.5 cm thick, 10 cm long and 5 cm wide. They are reddish-brown in color and each weighs approximately 130 gm in adults. Both kidneys receive blood from the renal artery; in a resting adult approximately 1.2 to 1.4 Litres of blood flows through both kidneys in one minute which means every 4 to 5 minutes all the circulating blood in the body passes through the kidneys. Kidneys help remove excess salt, water and waste products from the bloodstream. Like other endocrine organs, kidneys also secrete important hormones such as rennin and erythropoietin into the circulation. These hormones play significant roles in the production of blood cell and in the regulation of blood pressure.