4. The trachea is a tube that takes air into the bronchi.
5. The bronchi are two branches of the trachea.
6. The lungs are spongy organs made up of small sacs called alveoli.
The diaphragm is the muscle that creates the movements.
When we breathe, the oxygen in the air goes to the
blood through the alveoli, and the carbon dioxide from
the blood is released outside the body.
The excretory system
The excretory system filters waste subtances from the blood.
It removes them from the body through excretion.
The excretory system is made up of :
Urinary system. This is made up of the kidneys and the
The urinary system
1. The kidneys remove waste subtances from the
blood and they make urine.
2. The ureteres take urine from the kidneys to the bladder.
4. The urethra connects the bladder to outside.
The circulatory system
The circulatory system transports nutrients and oxygen to our cells. It is
made up of the heart, blood and blood vessels.
The heart is a muscular organ that pumps blood around the body.
The blood collects oxygen and nutrients and transports them to all the
cells. It also collects waste subtances and takes them to the sweat
glands and the urinary system.
The blood vessels. There are three types:
Arteries, veins and capillaries.
The arteries carry the blood from the heart to the rest of the body.
The veins carry the blood from all over the body back to the heart.
The capillaries are very thin vessels that reach all the cells of the body.
• Blood is a red liquid tissue made up of cells that float in a
liquid called plasma.
• There are three types of blood cells, red blood cells, white
blood cells and platelets.
• Red blood cells carry oxygen.
• White blood cells remove bacteria and viruses from the blood.
• Platelets are small fragments of cells that form blood clots.
The heart uses rhytmic systole and diastole movements to
pump the blood around the body.
1. Blood enters the atria through the veins.
2. Passes to the ventricles.
3. Blood comes out of the ventricles, through the arteries.
4. Travels all over the body.
• Human circulation is closed and double.
• Human is closed. In mamals, the heart septum
separates the two halves of the heart.
• Human circulation is double.The blood follows
• Pulmonary circulation.
• Systemic circulation.