Total teeth = 32, eight flat incisors at the front, fount pointedcanine and 20 flat-topped pre-molars and molars at the back of the mouth.
Tooth is covered by tough white enamel.
Enamel is the hardest substance in the body and resists almost everything except the acid produced by certain bacteria
Liver is the body’s chemical factory.
Liver is the largest organ in the body.
Liver carries out more than 500 different tasks.
Liver recycles old red blood cells.
Liver takes up and stores glucose from blood.
Liver also absorbs and stores fat and some vitamins.
Liver uses vitamin B12 for making new red blood cells.
Nearly two third of our body is water.
We loose about a liter and a half of water each day in sweating, breathing and urination.
Each kidney is made up of millions of tiny filtering units called Nephrons.
The nephrons can filter about 4 liters of blood every 5 minutes.
Each day about 200 liters of water leaves the blood and passes into the filters most of it is then reclaimed and return to the blood.
Only about a liter of water per day stays in the nephrons to leave the kidney and flow into the bladder as urine.
Urea is poisonous so the kidneys remove all of it from the blood.
The liquid, which leaves the kidney, as urine is about 96% water and just 4% salts and urea.
The urinary bladder can hold about half a liter of urine before we must empty it.
Amniotic sac is a protective bag of fluid in which the baby floats.
A baby is attached to the side of the womb by placenta.
Homo erectus means upright man
Homo sapiens mean wise man
Cells in intestine are easily worn away and live for only a few days.
Bone cells can last for 30 years.
The left ventricle pumps blood all round the body.
Capillaries are so small that they can fit between cells.
A living bone has layers of hard calcium phosphate on the outside and a heycomb of hard bone of living cells inside
Bone marrow supply blood cells over 2 millin every second
In the inner chamber of ear called cochlea, the vibrations send waves of movement through a fluid.
The cochlea is liked with thousands of sensitive hairs.
Thumping of heart or break out of sweat are caused by adrenaline.
From the age of about 5 years a child’s body grows steadily
Protein is a natural polymer
Muscles along the digestive system contract in a sequence called peristalsis to squeeze food along Nutrients of food are absorbed in blood in a long section of intestine called ileum. If uncoiled, ileum is 5-6 meters long
Eye contains only three types of color-sensitive cells. These cells (called cones) are on retina. The cones respond to red, green and blue light. Brain makes out other colors by combining the signals from these cells.
