Control and coordination · नियंत्रण एवं समन्वय
A free Biology lesson for Class 10 children.
The nervous system is made of nerve cells called neurons.
A neuron receives signals at its dendrites and passes them along its axon to the nerve endings.
A reflex action is a quick, automatic response, such as pulling your hand away from a hot pan. The spinal cord controls it.
The cerebrum of the brain does thinking, the cerebellum keeps balance, and the medulla controls breathing and heartbeat.
Hormones are chemical messengers made by glands and carried by the blood.
Insulin from the pancreas controls blood sugar. Adrenaline prepares the body for danger. Thyroxine needs iodine.
Shoots grow towards light, which is phototropism, and roots grow towards gravity, which is geotropism.
Auxin is the plant hormone that makes shoots bend towards light.