Circulation is the movement of blood through the circulatory system. Circulation carries nutrients and oxygen to all parts of the body, and collects waste substances, which can be dangerous.
Our heart works like a pump, and moves blood through the body.It never stops beating.
Blood vessels are tubes which transport blood through the circulatory system. There are three kinds: arteries, veins and capillaries.
- Arteries are the blood vessels which carry blood away from the heart.
-Veins are the blood vessels which carry blood into the heart.
-Capillaries are tiny blood vessels which connect arteries to veins. They reach every part of our body.
martes, 26 de octubre de 2010
BLOOD CIRCULATION
There are two circulatory systems:
-Pulmonary circulation is the movement of blood between the heart and the lungs. Blood leaves the heart through the pulmonary arteries and goes to the lungs. In the lungs, the blood absorbs oxygen and releases carbon dioxide. The blood then returns to the heart through the pulmonary veins.
-Systemic circulation is the movement of blood to the rest of the body. Blood with oxygen from the lungs leaves the heart through the aorta. It distributes nutritive substances and oxygen throughout the body. Finally, it returns to the heart through the vena cava.
-Pulmonary circulation is the movement of blood between the heart and the lungs. Blood leaves the heart through the pulmonary arteries and goes to the lungs. In the lungs, the blood absorbs oxygen and releases carbon dioxide. The blood then returns to the heart through the pulmonary veins.
-Systemic circulation is the movement of blood to the rest of the body. Blood with oxygen from the lungs leaves the heart through the aorta. It distributes nutritive substances and oxygen throughout the body. Finally, it returns to the heart through the vena cava.
The respiratory system
In addition to nutrients, we need oxygen to live. We breathe to obtain oxygen from the air.
This function is carried out by the respiratory system.It is made up of the nose, air passageways ( the tubes which carry air in and out of the body), and the lungs.
- First, the air enters through the nose. Then it passes through the pharynx, the larynx, and the trachea. Next, it goes through the two main bronchi and into each lung. In the lungs, the bronchi divide into smaller bronchioles. There are tiny sacs of air at the end of the bronchioles called alveoli.
-In the alveoli, oxygen from the air passes into the blood. The blood releases carbon dioxide which passes into the alveoli. It is toxic, and the body expels it.
Two movements, inhalation and exhalation, cause the air to circulate:
When we inhale, our lungs fill with air.
When we exhale, air leaves the lungs.
This function is carried out by the respiratory system.It is made up of the nose, air passageways ( the tubes which carry air in and out of the body), and the lungs.
- First, the air enters through the nose. Then it passes through the pharynx, the larynx, and the trachea. Next, it goes through the two main bronchi and into each lung. In the lungs, the bronchi divide into smaller bronchioles. There are tiny sacs of air at the end of the bronchioles called alveoli.
-In the alveoli, oxygen from the air passes into the blood. The blood releases carbon dioxide which passes into the alveoli. It is toxic, and the body expels it.
Two movements, inhalation and exhalation, cause the air to circulate:
When we inhale, our lungs fill with air.
When we exhale, air leaves the lungs.
The excretory system
Our body produces waste substances which go into the blood, and can be dangerous.
Excretion is the elimination of these waste substances.
-The kidneys are the organs of the excretory system. These two organs filter the blood and produce urine. This is made up of water (95%) and waste substances (5%). The urine leaves the kidneys and passes through the ureters, two tubes which go to the bladder. The urine accumulates there until it is expelled through the urethra.
-The sweat glands in the skin also help in excretion. They make sweat.
Excretion is the elimination of these waste substances.
-The kidneys are the organs of the excretory system. These two organs filter the blood and produce urine. This is made up of water (95%) and waste substances (5%). The urine leaves the kidneys and passes through the ureters, two tubes which go to the bladder. The urine accumulates there until it is expelled through the urethra.
-The sweat glands in the skin also help in excretion. They make sweat.
miércoles, 13 de octubre de 2010
activity
small intestine anus pharynx mouth oesophagus stomach large intestine
Follow the path that food takes.Put the organs of the digestive system in order: mouth...
Follow the path that food takes.Put the organs of the digestive system in order: mouth...
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