Human Body : Lungs

When we breathe in the air travels down the trachea to the lungs. Air enters via the bronchioles and eventually reaches tiny air sacs called alveoli.

Oxygen from the air dissolves into the layer of moisture around each alveoli and moves into minute blood vessels called capillaries.

From here the oxygenated blood is transported back to the heart and pumped round all the organs of the body.

Having delivered its life giving oxygen, the blood returns to the heart rich in carbon dioxide. This carbon dioxide takes the reverse path to the oxygen and is breathed out back into the atmosphere.

It is important for your body to get rid of carbon dioxide which is a waste product of respiration. the lungs help in the elimination of this toxic waste product.

Human Body : Heart

The heart is a pump.

In the human heart diagram, there are four chambers in this tireless pumping organ. All the chambers work in coordination pump blood round the body.The left chambers contain the oxygenated blood from the lungs.

This blood is pumped out of the heart via the arteries which transport the this oxygenated blood round the body to the muscles and vital organs.

The blood returns to the heart via veins. The veins return to the right side of the heart carrying carbon dioxide. The heart pumps this returning blood to the lungs.

In the lungs the carbon dioxide is removed from the blood and breathed out. The carbon dioxide is replaced with oxygen and returned to the left side of the heart to be pumped around the body again.


Human Body : Tongue

Your tongue is a mass of muscles. The specific arrangement of muscle fibres allows it to move freely in any direction inside the mouth to performs several different tasks, including eating, swallowing, speaking, licking, sucking, and helping to pronounce words when we speak.

Your tongue contains thousands of taste buds. Taste buds are small organs, embedded in the tongue that enable us to experience taste.

The tip or apex of the tongue accounts for the front one-third of the tongue. It is very mobile and rests against the incisor teeth in the mouth. The taste buds for “sweet” are on this part of the tongue.

The back two-thirds of the tongue form its body. The surface is slightly rough. This is this part of the tongue where the tongue tastes salty, bitter and sour flavours.

You can find out much more about the tongue here…

The Tongue by


Human Body : Nose

The function of nose in respiratory system is very important. It is responsible for filtering and inhaling air containing vital oxygen .

The septum divides the nasal cavity to create two equal sized nostrils. The fine hair or cilia in the nose behave like a mechanical filter removing particles from the air we breathe in.

The nose also pre-warms the air we breathe during inhalation to match body’s temperature .

Of course, the nose is also the organ responsible for our sense of smell. The nostrils contain six million cells that are sensitive enough to detect a huge number of different smells. Humans have the ability to detect as many as over one trillion distinct scents.

Learn more about the nose here…

The Nose by


Human Body : Ears

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The major functions of the ear are to help us to maintain the balance and to aid in hearing capabilities.The ear has three main sections:

The outer ear is the pinna, and its function is to gather the sound waves like a funnel and transmit to the middle ear through the ear canal.

The ear drum covers the other end of the canal.

The sound waves that strike the ear drum setup a vibration. This vibration then travels to the three small bones (ossicles) of the middle ear, (the malleus, stapes and incus). The bones of the middle ear move and strike the oval window. The vestibular window separates the middle ear from the inner ear.

The inner ear is also called the cochlea, which is a dual membrane, delicate in structure, with fluid between the membranes and lined with hair cells. The movement of the hair cells that line cochlea, in response to the sound waves, sends electrical impulses to the brain which interprets the sounds we hear.

Find out more about the ear here…

The human ear by

Human Body : Skin -the body’s largest organ

What is Skin? : The Structure of the skin

The skin is the outer covering which protects all the delicate body parts lying underneath it.

It is the largest organ of our body which consists of several tissues including sweat glands and hair follicles.

Our skin not only provides protection to the internal body parts, but also gives us our sense of touch; it is comprised of three main layers.

The outermost layer is called the epidermis  The epidermis acts as a barrier between our internal body parts and the external environment. Therefore, it is this layer of the skin which is responsible for preventing the entry of harmful foreign agents, such as bacteria, inside the body.

Beneath the epidermis is another layer of the skin, known as the dermis which contains hair follicles, sweat glands and sebaceous glands.

The skin’s innermost layer is known as subcutis. This is where fat is deposited to act as an energy store as well as an insulator. You can read more about the skin here…

What is Skin? : The Structure of the skin