Functions and Importance of Each Human Body Organ
The human body is a remarkable network of human anatomy organs, each playing a specialized role to keep us alive and thriving. The term “organ” refers to a group of tissues that come together to perform unique functions. Although there are various ways to categorize human body parts, experts generally agree on a list of organs in the human body that totals seventy-eight. In this guide, we will uncover what are the 78 organs in the human body in order, identify the 5 vital organs of human body, explore how they function, and discuss fascinating extras that make our page more informative than ever.
What Defines an Organ?
An organ is formed when similar cells and tissues work together to perform a specific function. For example, your heart pumps blood, your lungs aid in respiration, and your liver supports digestion and detoxification. These internal organs of human body and their functions are vital for sustaining life. In fact, studying these structures helps us understand crucial concepts about our health and well-being.
5 Vital Organs of the Human Body
Before diving into what are the 78 organs in the human body and their functions, let’s highlight the 5 vital organs of human body. These are absolutely critical for survival—if any one of these fails to function properly, life is at immediate risk without medical intervention.
Heart
Pumps blood throughout the body, supplying oxygen and nutrients.
Vital to circulatory health and maintaining blood pressure.
Brain
Central control system for thoughts, emotions, and body movements.
Regulates all voluntary and involuntary actions.
Lungs (Pair)
Facilitate the exchange of oxygen and carbon dioxide.
Essential for respiration and maintaining blood pH levels.
Liver
Largest internal organ and key for detoxification, bile production, and metabolism.
Helps in clotting and various biochemical processes.
Kidneys (Pair)
Filter out waste products and excess water from the blood.
Play a role in blood pressure regulation and maintaining electrolyte balance.
Explore, Human Respiratory System
Complete List of 78 Organs in the Human Body
Many learners often ask, “what are the 12 organs of the body?” or “what are the 78 organs in the human body in order?” The confusion arises because some sources focus on the major organs only, while others recognize additional structures such as glands, tissues, or newly classified organs (e.g., the interstitium). Below is a list of organs in the human body (in alphabetical order) recognized by most experts:
Note: Some items (like blood vessels) can be broken down further into arteries, veins, and capillaries. The exact counting may vary, but this remains the generally recognized list of organs in the human body.
Largest Organs in the Human Body
Among these human body parts, a few stand out due to their size and overall impact. Learning about them sheds light on how complex our human anatomy organs truly are.
Skin (Largest External Organ)
Offers protection from pathogens, regulates temperature, and prevents dehydration.
Houses various sensory receptors for touch, temperature, and pain.
Liver (Largest Internal Organ)
Weighs around 1.3 to 1.5 kg.
Oversees hundreds of functions, including metabolism and detoxification.
Brain
Protected by the skull and cerebrospinal fluid.
Coordinates and regulates body functions, thoughts, and emotions.
Lungs
Spongy, elastic organs for gas exchange.
Expand and contract roughly 12-20 times per minute at rest in adults.
Heart
Pumps about 2,000 gallons of blood a day.
Always working, even as we sleep.
Also, read Structure of Brain
Major (Vital) and Other Essential Organs
While all 78 human body parts name in the list have their importance, certain organs perform indispensable tasks:
Pancreas
Produces insulin, glucagon, and digestive enzymes.
Regulates blood sugar levels.
Small Intestine
Responsible for nutrient absorption.
Longest part of the alimentary canal.
Spleen
Filters blood, recycles old red blood cells, and supports immune function.
Stomach
Performs mechanical and chemical digestion.
Produces acid and enzymes for breaking down food.
Spinal Cord
Major conduit for transferring signals between the brain and the rest of the body.
Essential for reflex actions and coordination.
These internal organs of human body and their functions collectively keep your systems running in harmony.
Also, read Human Excretory System
Recent Organ Discoveries
Interstitium: Newly recognized by some researchers as a fluid-filled compartment that surrounds tissues.
Mesentery: Once thought to be just a fold of tissue, it’s now recognized as a continuous organ that supports and positions the intestines.
Such discoveries reflect how our understanding of human anatomy organs evolves with ongoing research.
Fun Task: Organ Spotting Challenge
Try this engaging activity to see how well you can identify key human body parts:
Gather some coloured stickers or markers.
Print or draw a simple outline of the human body.
Label at least 15 organs from the list of organs in the human body on your diagram.
Challenge a friend or family member to do the same. Compare your drawings and see who got more correct!
This hands-on task helps you remember human body parts name and placement in a fun way.
Interactive Quiz: Test Your Organ Knowledge
Which organ is responsible for filtering blood and removing waste products?
A. Pancreas
B. Kidneys
C. Heart
D. Lungs
The largest internal organ in the human body is:
A. Skin
B. Liver
C. Brain
D. Heart
Which organ produces insulin?
A. Thyroid
B. Adrenal gland
C. Pancreas
D. Pituitary gland
The fluid that cushions the brain is called:
A. Bile
B. Plasma
C. Synovial fluid
D. Cerebrospinal fluid
Lymph nodes are primarily associated with:
A. Digestion
B. Immune function
C. Respiration
D. Hormone regulation
Which of the following is part of the 5 vital organs of human body?
A. Spleen
B. Kidneys
C. Stomach
D. Pancreas
The alveoli are found in the:
A. Lungs
B. Liver
C. Brain
D. Stomach
The small tube carrying urine from the bladder to the outside of the body is called:
A. Ureter
B. Urethra
C. Trachea
D. Vas deferens
Which is the outermost covering that protects the entire body?
A. Skin
B. Hair follicles
C. Nails
D. Bone
The organ that helps in pumping blood is the:
A. Liver
B. Lungs
C. Heart
D. Kidneys
Check Your Answers Below
1 – B, 2 – B, 3 – C, 4 – D, 5 – B, 6 – B, 7 – A, 8 – B, 9 – A, 10 – C
FAQs on What Are the 78 Organs in the Human Body?
1. What is the basic definition of an organ in the human body?
An organ is a structure made of two or more different types of tissues that work together to perform a specific, complex function. For example, the heart is an organ composed of muscle, nervous, and connective tissues that cooperate to pump blood throughout the body.
2. How many organs are currently recognised in the human body?
Scientists generally agree there are 78 recognised organs. However, this number is not set in stone and can change with new scientific discoveries. For instance, the mesentery was recently reclassified as a distinct organ.
3. What makes an organ 'vital' for survival?
An organ is considered 'vital' if the human body cannot survive without it. The five vital organs are the brain, heart, lungs, liver, and kidneys. Each one performs a function so essential that its failure leads to death without medical intervention.
4. What is the main difference between a tissue and an organ?
The key difference is their level of organisation and complexity. A tissue is a group of similar cells working on a single task (e.g., muscle tissue). An organ is a more complex structure made of multiple types of tissues that work together to perform a broader function (e.g., the stomach, which has muscle, nervous, and lining tissues).
5. Why is the skin considered to be an organ?
The skin is classified as an organ because it consists of multiple tissue layers (epidermis, dermis) working together to perform vital functions. It acts as a protective barrier, helps regulate body temperature, and contains nerves for sensation, making it the body's largest organ.
6. How are the 78 organs grouped to work together in the body?
Organs that cooperate on a major function are grouped into organ systems. This teamwork allows the body to perform complex tasks efficiently. Key examples include:
- The Digestive System: Includes the stomach, liver, and intestines to process food.
- The Respiratory System: Includes the lungs and trachea to handle breathing.
- The Nervous System: Includes the brain and spinal cord to control the body.
7. Why do some sources mention a 79th organ like the 'interstitium'?
The number of organs can be debated as scientific understanding grows. The interstitium, a body-wide network of fluid-filled spaces in connective tissue, was recently proposed as a new organ. This happens when scientists identify a structure as having a unique, unified form and function that was not previously understood.
8. Are there any organs that a person can live without?
Yes, while vital organs are essential, the body has several non-vital organs that can be removed without causing death. Common examples include the appendix, gallbladder, spleen, and tonsils. People can also live a healthy life with just one kidney or one lung.
9. What are some examples of smaller, less-known organs in the human body?
Beyond major organs like the heart and lungs, the human body has many smaller ones with specific roles. Examples include the lacrimal glands that produce tears, the parathyroid glands that regulate calcium, and the epiglottis, which prevents food from entering the windpipe.
10. How do single-function organs differ from multi-function organs?
Some organs have a very specialised role, while others are versatile. For example, the heart's primary function is to pump blood. In contrast, the liver is a multi-function organ that performs over 500 different tasks, including filtering blood, producing bile for digestion, and storing energy.
