The human body By Ela Cari Morris Please click on title to enter.

Click on any of the topics to read the information. Main Menu Click on any of the topics to read the information. BRAIN MUSCLES VEINS BLOOD SKIN HEART BONES BREATHING

Please press Hide Answer before going back to main menu VEINS Show answer Hide answer Why do veins look blue if blood is red? Blood is ALWAYS red. Oxygen-rich blood is bright red as it leaves the heart. When it returns in veins without much oxygen, it’s still red, but it’s a deeper, darker red. But our veins look blue because blue light is reflected back to our eyes even though veins contain deep, dark red blood. Blue light does not penetrate human tissue as deeply as red light does. As a result, veins that are close to the surface of the skin will be more likely to reflect blue light back to the eye. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu BREATHING Please press Hide Answer before going back to main menu Facts Questions Show answer Why do we breathe? Hide answer The fresh air in the countryside contains more oxygen than stale city air. This is because plants and trees of the forest take in carbon dioxide and give out oxygen all day long. You breathe because you need oxygen to stay alive. Show answer Why do we need oxygen? Hide answer Your body needs oxygen to stay alive. When you breathe in, oxygen enters your lungs. They are designed to absorb as much oxygen as possible. The oxygen is absorbed into your bloodstream through your lungs and carried to every part of your body that needs it. Your cells need energy to live and work. When oxygen enters the cells the energy is released and the cells can function. When you eat food, the energy is stored in the cells. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu SKIN Please press Hide Answer before going back to main menu Facts Questions Show answer What is your skin? Hide answer The palms of your hands, your fingers and the soles of your feet are covered in minute ridges and grooves which make patterns. The pattern on your fingertips are unique to you – no-one else has the same pattern, (unless you’re twins!) Your skin is the largest of the body’s organ. On average, an adult has about 2sq.m of skin. Show answer What does your skin do? Hide answer Your skin keeps your whole body together and does many other jobs as well; It controls your body temperature It is waterproof It protects you from poisons, diseases and the sun’s ultra-violet rays It feels heat and pain It builds up Vitamin D to help you grow strong bones It stores fat It absorbs oxygen and releases carbon dioxide. Within one square metre of your skin you have 4 metres of nervous, which take messages to the brain. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu BLOOD Facts Please press Hide Answer before going back to main menu Questions White blood cells are an important part of the body’s immune system. They defend against certain bacteria, viruses, cancer cells, infectious diseases and other unwanted materials. Show answer How much blood do you have in your body? Hide answer Blood makes up around 7% of the weight of a human body. Show answer What is blood donation? Hide answer Blood contains red blood cells, white blood cells and platelets. Many generous humans around the world give blood donations every year. This blood is used in important blood transfusions or made into medication. There are strict rules that limit the number of people who can volunteer blood donations. These include checking for diseases that could be transmitted as well as ensuring recovery time for the donor’s body to replace its own blood. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu BONES Please press Hide Answer before going back to main menu How many bones do you have? How can we protect Our bones? Show answer Show answer Hide answer Hide answer An average person has 206 bones. Protect your skull by wearing a helmet for bike riding and other sports. If you play sports like football or rugby, always wear all the right equipment. Strengthen your skeleton by drinking milk and eating other dairy products. They all contain calcium, which helps bones harden and become strong. Be active! Another way to strengthen your bones is through exercise like running, jumping, dancing, and playing sports. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu BRAIN Please press Hide Answer before going back to main menu The human brain is like a powerful computer. It stores our memory and controls how we as humans think and react. It has evolved over time and features some incredibly intricate parts that scientists still struggle to understand. How heavy is our brain? How big is our brain? Show answer Hide answer Show answer The human brain is over three times as big as the brain of other mammals that are of similar body size. Hide answer The brain of an adult human weighs around 3 pounds (1.5 kg). Although it makes up just 2% of the body's weight, it uses around 20% of its energy. CLICK TO GO TO MAIN MENU

Please press Hide Answer before going back to main menu MUSCLES Please press Hide Answer before going back to main menu How many muscles do you have? Are there different types of muscles? Show answer Hide answer Show answer Hide answer You have three different types of muscles in your body: smooth muscle, cardiac muscle, and skeletal muscle. Muscles are all made of the same material, a type of elastic tissue (sort of like the material in a rubber band). Thousands, or even tens of thousands, of small fibres make up each muscle. Did you know you have more than 600 muscles in your body? They do everything from pumping blood throughout your body to helping you lift your heavy backpack. You control some of your muscles, while others — like your heart — do their jobs without you thinking about them at all. CLICK TO GO TO MAIN MENU

HEART What makes your heart happy? What is your heart made of? Healthy food Exercise Not smoking Keeping calm and relaxed What is your heart made of? Your heart is made of Arteries, Veins and Muscle. Where does the heart live? The heart lives on the left side of the chest, under the breast bone. How big is your HEART? Your fist is the same size as your heart. CLICK TO GO TO MAIN MENU

Electricity going through your heart makes the muscle cells contract. Blood that leaves the heart is carried through arteries. The main artery leaving the left ventricle is the aorta while the main artery leaving the right ventricle is the pulmonary artery. The study of the human heart and its various disorders is known as cardiology. Electricity going through your heart makes the muscle cells contract. The heart is made up of four chambers, the left atrium, right atrium, left ventricle and right ventricle. The heart is one of the most important organs in the human body, continuously pumping blood around our body through blood vessels. You might have felt your own heart beating, this is known as the cardiac cycle. When your heart contracts it makes the chambers smaller and when your heart relaxes again the chambers get bigger and are filled with blood coming back into the heart CLICK TO GO TO MAIN MENU