Digestion is the process of breaking food into a usaeable form and making the nutrients available. Digestion takes place in the digestive system. Your digestive system consist of -:
A digestive tract
Organs off the digestive tract
You can see the digestive system in figure 1.1.
Your digestive system consists of -:
Mouth(breaks down food)
Oesophagus(pushes the food down to the stomach)
Stomach(digests the food mechanically and chemically)
Duodenum(carries chemicals important for digestion)
Small intestine(absorbs digested food)
Large intestine(water is absorbed from what is left from the food)
Rubrica: : The Digestive System and the digestive tract
Refers to as a series of chemicals that takes place in cells to release energy.Your respiratory sytem takes in air and extracts oxygen from it.The air follows a path that starts with the trachea, a tube about the diameter as a garden hose, and finishes in microscopic sacs called alveolus. The alveoli within the lungs are closely packed together making the lung like a sponge.The walls of the alveoli are only one cell thick, so are the walls of the capillaries. Gases are exchanged where the surface of the alveoli and surface of the capillaries are in contact.
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The more energy your body consume, the more oxygen and glucose are required.
When you consume more energy than your body requires, the excess nutrients are converted into fats which leads you to become overweighted.
When you consume less energy than your body requires, you start to use muscle tissue, which weakens the muscles of your body,
To get more oxygen into your cells, you have to breathe more quickly or more deeply.
There are three main phases of a heartbeat-:
The two atria contract pushing the blood down into the ventricles.
The ventricles contract, forcing blood out of the heart to the body and lungs.
The two atria relaxes and fills with blood.
Your circulatory system consist of blood, heart and blood vessels. The heart is the engine room, it pumps the blood continuously to keep it moving, the heart is made up of a special untired muscle called cardiac muscle. The blood vessels are three types: arteries, veins and capillaries. Arteries carry blood away from the heart, veins carry blood back to the heart while capillaries allow blood to flow continuously.
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Blood carries oxygen, nutrients and water to the cells and also carries wastes such as carbon dioxide from the cells. Blood also helps maintain your body temperature by spreading the heat around. In blood, there are red blood cells, white blood cells, platelets and plasma.
Red blood cells are made in bone marrow and contain haemoglobin which give cells their red colour when they are carrying oxygen.
White blood cells are part of the immune system that fight disease.
The only liquid organ-BLOOD
Platelets are broken up bits of cells produced in the bone marrow and help blood to clot.
Plasma is a clear yellowish liquid that is only 90% water and it is where red blood cells and white blood cells as well as platelets are suspended.
Blood is the only internal organ that exists as a liquid in shape.