general science

Longest bone in human body
Femur (thigh bone)

Hardest material in the human body 
Tooth enamel

Smallest bone
STAPLES the middle ear

Strongest muscle
Jaw muscle

Largest external organ
Skin

Largest internal organ
Liver

Smallest gland
Pituitary

Largest artery
Aorta

Smallest blood vessel
Capillary

Element most common in human body
Oxygen (65%)

Mineral most common in human body
Calcium

Compound most common in human body
Water

Pigment which gives a dark colour to the skin
Melanin

Nails are modification of
EPIDERMIS (external layer of skin)

Sebaceous glands in human body secrete
Sebum or oil

Muscles are attached to bones by connective tissues called
Tendons

Bones are attached to bones by
Ligaments

Lachrymal glands in human body secrete
Tears

The volume of blood in an adult is
4.7 to 5 litres

The total number of bones in human body is
206

The most common type of blood group is
Type O