Hormones

Hormones are very important biochemicals produced in the body by specialized group of cells called glands. Chemically hormones are composed of proteins. These regulate the various metabolic reactions in the body. These are required only in small amount. Their low or...

Endocrine System

Endocrine system is a group of glands that work together to control and coordinate the activities of animals. Glands are groups of cells which produce specific chemicals called hormones. The first hormone was discovered by English scientists William Bayliss and Ernest...

Electroencephalogram

Electroencephalogram is a record of electrical activities of brain which is used by doctors to diagnose brain ailments.The EEG of a patient is done by doctors by using an instrument called electroencephalograph. Electroencephalograph consists of two electrodes which...

Reflex Action

Reflex action is a sudden and involuntary response of effectors (muscles and organs) to a stimulus. Withdrawl of hands when touched by hot things, watering of mouth on seeing favourite food, coughing, sneezing and blinking of eyes are examples of reflex actions. The...

Main Division of Nervous System

The nervous system can be divided into three main divisions: The central nervous system (CNS) The peripheral nervous system (PNS) The autonomic nervous system (ANS) Central Nervous System The central nervous system consists of brain and spinal cord. Peripheral Nervous...

Nervous System of Insect

In an insect, a long nerve cord is present which runs along the whole body. Like hydra, insects also do not have a brain. Instead of brain, many ganglia are present at intervals on the nerve cords. A ganglia is a mass of nerve cells. The largest ganglion is present in...