Respiratory System

Breathing is so vital to life that it happens automatically. Each day, you breathe about 20,000 times, and by the time you're 70 years old, you'll have taken at least 600 million breaths.

All of this breathing couldn't happen without the respiratory system, which includes the nose, throat, voice box, windpipe, and lungs.

Why Do I Yawn?

When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath -a YAWN.

Why Do I Sneeze?

Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze.

What Causes Hiccups?

Hiccups are the sudden movements of the diaphragm. It is involuntary - you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten to fast, or maybe some substance in the blood could even have brought on the hiccups.

Interesting Facts about our Respiration

- We breathe 13 pints of air every minute.

- Each lung contains 300-350 million respiratory units called alveoli, making it a total of 700 million in both lungs.

- More than half a litre of water per day is lost through breathing.

- People under 30 years of age take in double the amount of oxygen in comparison to a 80 year old.

- Yawning brings more oxygen to the lungs.

- The right lung is slightly larger than the left.

- Hairs in your nose help to clean the air we breathe as well as warm it. The highest recorded "sneeze speed" is 99 miles per hour!

- The surface area of the lungs is roughly the same size as a tennis court.

- If placed end to end, capillaries would extend 960 miles.

- We lose half a litre of water every day through breathing.

- A person at rest breathes between 12-15 times a minute.

- The breathing rate is faster in children and women than it is in men.

Circulatory System

With each heartbeat, blood is sent throughout our bodies, carrying oxygen and nutrients to all of our cells. Each day, 2,000 gallons of blood travel many times through about 60,000 miles of blood vessels that branch and cross, linking the cells of our organs and body parts.

From the hard-working heart to our thickest arteries and to capillaries so thin that they can only be seen through a microscope, the heart and circulatory system (also called the cardiovascular system) are our body's lifeline, delivering blood to the body's tissues.

Interesting Circulation Facts:

- The heart muscles will stop working only when we die.

- Every second, 15 million blood cells are destroyed in the human body.

- Platelets, which form a part of the blood cell component, are produced at the rate of 200 billion per day.

- An adult human body contains five to six litres of blood and an infant has about one litre of blood.

- Except the heart and lungs, all the other parts of the body receive their blood supply from the largest artery of the body, the aorta.

- The pulmonary vein is the only vein in the human body that carries oxygenated blood while all the other veins of the body carry deoxygenated blood.

- Human blood is colourless. It is the haemoglobin; a pigment present in the red blood cells that is responsible for the red colour of the blood.

- Heartbeat is nothing but the sound produced by the closure of valves of the heart when the blood is pushed through its chamber.

- A women's heart beat is faster than that of a man's.

- The human heart continues to beat even after it is taken out of the body or cut in to pieces.

- On an average, the human blood circulates through the whole body every 23 seconds.

- On an average, the adult's heart pumps about 4,000 gallons of blood each day.

- The left side of human heart is much thicker and stronger than the right side.

- Human blood is a make up of red blood cells carrying oxygen, white blood cells that fight disease, platelets that help the blood to clot, and a liquid called plasma.

- Every day 440 gallons of blood flow through the kidney.

- Red blood cells last only for about 4 months before they wear out.

- Red blood cells are the only cells in the body that do not have a nucleus.

- There are about 30 - 40 billion white blood cells present in our body to fight against infective and foreign organisms.

- Capillaries are so small that it would take ten of them to equal the thickness of a human hair.

- The human heart beats 30 million times a year.