HUMAN ORGANS

PRERNA FOR IAS

HUMAN ORGANS

1. Brain

The brain is the control center of the human body and is protected by the skull. It controls all voluntary and involuntary activities, including movement, breathing, heartbeat, thinking, memory, emotions, and coordination. It receives information from the body's sensory organs, processes it, and sends appropriate responses through the nervous system. The brain is divided into the cerebrum, cerebellum, and brainstem, each performing specialized functions. It also regulates hormone secretion through the hypothalamus and pituitary gland. A healthy brain is essential for learning, decision-making, communication, and maintaining normal body functions throughout life.

2. Heart

The heart is a muscular organ located in the chest between the lungs. It functions as a powerful pump that continuously circulates blood throughout the body. The heart supplies oxygen, nutrients, hormones, and immune cells to tissues while removing carbon dioxide and waste products. It consists of four chambers: two atria and two ventricles. The average adult heart beats about 100,000 times per day, pumping nearly 5 liters of blood every minute. Proper heart function is essential for maintaining blood pressure, supporting all organs, and ensuring continuous circulation necessary for life and overall health.

3. Lungs

The lungs are the primary organs of the respiratory system responsible for breathing and gas exchange. They absorb oxygen from inhaled air and remove carbon dioxide produced during metabolism. The right lung has three lobes, while the left lung has two lobes to accommodate the heart. Tiny air sacs called alveoli provide a large surface area for efficient gas exchange. Healthy lungs maintain oxygen supply to every body cell and help regulate blood pH. They also filter small blood clots and harmful particles. Proper lung function is essential for energy production and overall survival.

4. Liver

The liver is the largest gland in the human body and is located in the upper right abdomen. It performs over 500 vital functions, including detoxifying harmful substances, metabolizing nutrients, storing glycogen, producing bile, and synthesizing important proteins such as albumin and clotting factors. Bile produced by the liver helps digest fats in the small intestine. The liver also regulates blood sugar, cholesterol, and vitamin storage while removing toxins and drugs from the bloodstream. Because of its remarkable regenerative ability, the liver can repair itself after injury. It is essential for digestion, metabolism, and maintaining internal balance.

5. Stomach

The stomach is a J-shaped muscular organ located between the esophagus and small intestine. It temporarily stores food and mechanically churns it into a semi-liquid mixture called chyme. The stomach secretes gastric juice, which contains hydrochloric acid, pepsin, and mucus. Hydrochloric acid kills harmful microorganisms and activates digestive enzymes, while pepsin begins protein digestion. The stomach also produces intrinsic factor, which is necessary for Vitamin B₁₂ absorption. Controlled contractions mix food thoroughly before releasing it into the small intestine. The stomach plays an important role in digestion and preparing nutrients for further absorption.

6. Intestines