Human Anatomy and Physiology

Human Anatomy and Physiology

Understanding the human body is the key to living healthily. These days, humans are making more effort to attain healthier lives. One of the best ways to achieve this aim is to understand human anatomy and physiology.

This understanding is important to help us know what to eat, how to work out, and other aspects of life. While human anatomy and physiology is a college course, we intend to break it down for easy understanding. After reading this post, you will have a better understanding of how to treat your body.

Defining Anatomy and Physiology

Before we dive into more complicated issues, it is best to set the foundation by defining these two terms. Even though they are medical terms, they aren’t so difficult to understand.

Anatomy, in layman terms, is the study of the relationship and structure of human body parts. In other words, it gives us a clear picture of each of the different body parts and they relate to other parts.

Physiology, on the other hand, studies the whole body as a unit and the function of each part. Looking at this definition, physiology seems to be broader. However, both terms relate and are hardly ever separated.

There are certain specializations that fall under these interesting sciences, they are:

  1. Gross anatomy/Macroscopic anatomy – This specialization studies body parts that are in a clear view of the naked eye. This includes parts like the bones and the heart.
  2. Histology –This study focuses on the microscopic study of tissues.
  3. Cytology – This study focuses on the microscopic study of cells.
  4. Neurophysiology – This specialization focuses on the study of the operations of the nervous system.

How are Living Systems Organized?

We cannot discuss human anatomy and physiology without first discussing the organization of living systems. Truth be told, we can define living systems from different perspectives. Each of these perspectives gives a clearer picture of the reasons and modes of function of living systems.

We have broken down the organization into different modules below:

Module 1 – The chemical level

At this point, we deal with atoms and molecules (a combination of atoms). We also deal with the chemical bonds that hold atoms together to create a framework. It is upon this framework that the whole of living activity rests.

Module 2 – Smallest Unit of Life

The smallest unit of life is the cell. Within the cell, we have organelles which are specialized bodies that perform specific cellular functions. As a result, we have some cells that have specialized functions such as the bone, muscle, and nerve cells.

Module 3 – Tissues

These are a group of cells that work together to perform a specific function. A vivid example is the muscle tissue that is made up of muscle cells.

Module 4 – Organs

Organs are groups of different tissues that work together to perform a specific activity. One of the most famous organs is the heart which comprises of nervous, muscular, epithelial, and connective tissues.

Module 5 – Organ System

This is the coming together of two organs or more to complete a task. An example is a digestive system that involves several organs including the stomach, mouth, large and small intestines, liver, and pancreas.

Module 6 – Organism

Organisms are systems that possess all the characteristics of living things. These characteristics include obtaining and processing energy, responding to stimuli, and reproduction to mention a few.

Body Systems

It is impossible to discuss human anatomy and physiology without talking about body systems. We have established the fact that organ systems are groups of different organs working for a cause. Our bodies have several systems which we will shed some light on in this section.

Circulatory system

This system is saddled with the responsibility of moving blood, hormones, nutrients, oxygen, and carbon dioxide around the body. The circulatory system is made up of the following organs:

  1. Heart
  2. Blood
  3. Arteries
  4. Veins
  5. Blood vessels

Digestive system

This system is made up of different connected organs that help the body ingest food and break it down. They also help to absorb the nutrients in the food and get rid of waste. The digestive system is made up of the:

  1. Mouth
  2. Esophagus
  3. Stomach
  4. Small intestine
  5. Large intestine
  6. Rectum
  7. Anus

The pancreas and liver also play a major role in this system as they help in synthesizing digestive juices.

Endocrine system

This system is made up of eight glands that release hormones into the bloodstream. Each of the hormones released travels to different tissue to regulate different functions. Some of the functions include growth, sexual function, and metabolism.

Immune system

This system is also known as the body’s defense system. It helps to fortify the body against viruses, bacteria, and different kinds of pathogens. The immune system consists of the following:

  1. Spleen
  2. Lymph nodes
  3. Bone marrow
  4. Lymphocytes
  5. Thymus
  6. Leukocytes

Lymphatic system

This system also plays an important role in defending the body against disease-causing organisms. It consists of:

  1. Lymph nodes
  2. The lymph ducts
  3. Lymph vessels

The job of this system is to synthesize and move lymph. Lymph is a clear fluid containing white blood cells that help your body combat infection. This system is also responsible for ridding body tissues of excess lymph fluid which it restores to the blood.

Nervous system

This system is in charge of both involuntary and voluntary action. It also transmits corresponding signals to different parts of your body. The nervous system is consist of:

  1. Central Nervous System (CNS) – This includes the spinal cord and the brain.
  2. Peripheral Nervous System (PNS) – This is made up of every nerve that connects the rest of your body to the CNS.

Muscular system

This system is made up of 650 muscles. Muscles have several functions including aiding movement and blood flow. Your body has three kinds of muscles and they are:

  1. Skeletal muscle – These are the muscles connected to the bones and aid with voluntary movement.
  2. Smooth muscle – You find these muscles in the organs and they assist with moving substances within organs.
  3. Cardiac muscles – As the name implies, they are located in the heart. They perform one function, assist the heart in pumping blood.

Reproductive system

This system has one primary function, to help us reproduce. The reproductive system in males is different from that in females.

  1. The male reproductive system is made up of the penis and testes (that produce the sperm).
  2. The female reproductive system is made up of the vagina, uterus, and ovaries (that produce the eggs).

At conception, a sperm cell and an egg cell fuse to form a zygote. This implants in the uterus and begins to grow over 9 months.

Skeletal system

This system is the framework of our bodies that helps in providing support. It is made up of 206 bones. All these bones are connected by ligaments, cartilage, and tendons. Asides helping us move around with ease, this system also helps in producing blood cells and storing calcium. Many people don’t know this but the teeth also fall under this system even though they aren’t bones.

Respiratory system

This system is responsible for helping the body inhale oxygen and exhale carbon dioxide. The process is known as breathing and it is very important to all of our processes. The respiratory system is made up of the diaphragm, lungs, and trachea.

Urinary system

This system has the sole responsibility of eradicating urea from our bodies. Urea is a by-product of several foods after the digestion process. This system is made up of:

  1. Two kidneys
  2. Two ureters
  3. Bladder
  4. Two sphincter muscles
  5. Urethra

Urine is produced in the kidneys and is transported from here through the ureters to the bladder. From here it leaves the body via the urethra.

Integumentary system

This system is a fancy name for the skin and it is the largest organ in the body. It protects all our internal organs and processes from the physical environment. This system is your body’s first defense against viruses, bacteria, and other disease-causing organisms.

The skin is also responsible for regulating body temperature and eliminating waste via perspiration. Other constituents of this system are the nails and hair.

Human Anatomy and Physiology: Fun Facts

Now that you know the makeup of the body system, let’s see some human anatomy and physiology fun facts.

  1. There are almost 100 trillion cells in the human body.
  2. The number of bacteria in the body is about 10 times the number of cells.
  3. An adult takes an average of 20,000 breaths every day.
  4. The kidneys process up to 50 gallons of blood every day. They do this to filter out 0.5 gallons of water and waste.
  5. There are around 100 billion nerve cells present in the human brain.


Human anatomy and physiology is a very wide field. However, we have brought you a little aspect in this post and we hope this has been helpful? If you want to share some more with us, drop your points in the comments section.

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