Organs are the body parts formed by a group of tissues. They are the parts of the human systems and key structures in the human anatomy.
In the human body, there are many organs starting from head to limbs.
Many physiological functions are associated with the organs of the body systems.
Disorder of any of these organs significantly alters the health and well-being of an individual.
List of Organs of the body include:
- Organs of digestion: Stomach, liver, small intestine, large intestine, rectum, and anus.
- Organs of respiration: Lungs, nose, bronchi.
- Organs of excretion: Kidneys, urinary bladder, urethra
- Organs of the endocrine system: Pituitary gland, adrenal, thyroid, pancreas, parathyroid, prostate glands.
- Organs of circulation: Heart, blood vessels, spleen.
- Organs of senses: Skin, tongue, nose, eyes, ears.
- Organs of reproduction: Uterus, testis & penis in male, ovaries & mammary glans in the female.
- Organs of the nervous system: Brain and spinal cord.
Organs of the body and their function:
It has folding called rugae by which it expands to accommodate more food. Food consumed stays in the stomach for about an hour. Stomach wall secrete HCl which destroys any microbes in the food. Further, it readily absorbs water and alcohol and digests some portion of carbohydrates.
Small intestine: This is as long as few meters. The food from stomach enter the small intestine and stays for 8 hours. Here the food is digested and also the nutrients absorbed into the blood.
Large intestine: This is an extension of the small intestine but is wider. It is divided as ascending, transverse and descending intestine. It helps in absorption water before being excreted as feces. Further host many friendly bacteria which synthesize Vitamin-K and also help in absorption of vitamin-B12.
Liver: It is considered as the biggest organ in the body. It is located on the right-hand side above the stomach. It is a key organ of metabolism and one of the important organs human body has to detoxify substances. It helps to convert any toxic substances or drugs into water soluble inert substances. These are then easily excreted by the kidneys. It is the organ where glucose is stored as glycogen and fat are converted to high-density and low-density lipo proteins. It is also the place where bile is formed and released into the intestine for excretion. It is the most robust organ in the body. Damage to any portion of the liver is regenerated and repaired for effective function.
Heart: This is the major organ of the blood circulation system.
It helps pump the blood to reach deeper most tissues of the body.
It is the organ which functions non-stop from birth to death of an individual.
It has veins flowing in blood from the back and arteries going out of the heart.
In an adult, it beats at an average of 72 beats per minute.
Arteries, veins & Capillaries:
These are duct like organs which are connected to the heart. Arteries carry blood from heart to all the tissues and cell of the body. Veins bring impure blood from all the tissues and cells back to the heart. Capillaries are finest ducts which emerge from arteries and converge back into veins. They reach deeper most cells and provide nutrition and collect waste for expulsion by blood. There are few structural and functional differences between arteries and veins.
Lungs: These are the major organs of respiration. They help in taking of oxygen-rich air from the atmosphere into the body and give out carbon-dioxide.
The oxygen from the air in the lungs is taken by blood when it circulates through. These lungs are balloon-like and have the capacity to expand and relax. The average capacity is 4 liters of air.
It is made up of nerve cells and neuroglia. It has parts like cortex, cerebral hemisphere, cerebellum, medulla oblongata, pons. It extends into the spinal cord. Its important functions include judgment, memory, reasoning, sleep, temperature control, body movements, reflex actions etc. It exerts its action through neurotransmitters.
Spinal cord: This is the cord located in the vertebral column. It begins from the brain and extends till hip bones as the sacrum. It has many nerves passing through the entire body.
Kidneys: These are bean-shaped brownish organs located on two sides of the body. They are located on the dorsal (back side) on two sides of the vertebral column.They are the organs of excretion which filter waste from the blood. They are made of millions of nephrons which are the actual elements of excretion.
Ureters: These are the long ducts which connect kidneys to the urinary bladder. They carry the formed urine from nephrons to the bladder for expulsion.
Urinary bladder: This is a storage vesicle which stores urine brought from kidneys by the ureters until there is voluntary urination.
Skin: This is the largest organ of the body in terms of area.
It accounts to few meters. It covers the whole body, gives shape and protects the inner tissues from germs. It also acts as an organ of the sense of touch. The skin has sweat ducts, oil glands, and hair. In times of excess heat, body expels sweat through the skin to reduce the temperature. Along with sweat sodium chloride and other waste are excreted from the body. Thus skin also acts as an organ of excretion.
Eyes: The most vital organs of the body.
They are responsible for vision. They have connections with the brain through optic nerves which help in vision.
Ears: These are the organs of hearing. They are a pair each located on one side of the head. They are responsible for the sense of hearing and maintenance of balance.
Nose: This is an organ of respiration but also has the function of the sense of smell. It has olfactory nerve endings in the nasal layers which predict the smell.
Tongue: The organ of taste in the mouth. It has sensory buds to recognize taste. It is movable and helps in speech and talking.
Pancreas: This organ located near stomach acts as both exocrine gland and also endocrine gland. Exocrine gland secretes digestive enzymes like amylase, trypsin, lipase which digest carbohydrates, proteins and fats respectively.
While the endocrine part secretes hormones like insulin, somatotrophin which regulate glucose levels in the blood.
Thyroid gland: This is an endocrine gland located near the neck region. It secretes thyroid hormones which regulate metabolism and also body temperature.
Parathyroid gland: This is also endocrine gland located along with thyroid gland. They secrete parathormone which regulates calcium levels in the blood.
Adrenal gland: This endocrine gland has two portions as internal medulla which secretes epinephrine while the outer cortex secrete mineral and glucocorticoid hormones. Epinephrine is the hormone of fight or flight (emotion related) while corticoids regulate body metabolism.
Spleen: This organ is a part of the lymphatic system. It also helps in the breakdown of red blood cells.It is located in the belly region near intestines and stomach.
They are a pair and help in the formation of ova which can fertilize with sperm and go on to form a baby.
Uterus: This organ is well developed in females. It helps to host the fertilized zygote to grow into a babe. It provides all the required nutrients to the baby during the period.
Testis: These are the external gland like structures present in males near the groin. They have vas-differentia which forms sperms.
Prostate gland: This gland secretes prostate hormone. Present in males helps in the passage of sperms from the urethra.
Bone marrow: This is a tissue and not an organ and is present inside the large bones. It exists as yellow and red bone marrow. As a person ages, the red portion of it turns yellow. This bone marrow is important in production of red blood cells, white blood cells and even thromboctyes.
Reference: Principles of Anatomy and Physiology.
Knowledge of organs of the body, their functions helps one understand the disease mechanisms and also gives ideas for pharmacology based intervention.