Page 1 - 2.3-LN

SAI International School
Std -X, Subject- BIOLOGY
Chapter- Control and Coordination
Sub Topic- Hormones in animals, feedback mechanism
Module- 15
Lesson Notes

COORDINATION
• The working together of various organs of the body of an organism in a proper
manner to produce appropriate reaction to a stimulus is called coordination.
• All animals have a nervous system for control and coordination.
• The action of the nervous system is supported by the action of various
hormones to facilitate control and coordination.

TYPES OF GLANDS
▪ Glands are known to secrete hormones and enzymes.
▪ There are two types of glands viz. endocrine and exocrine.
▪ Endocrine glands lack the ducts and hence, release the hormones directly into
the blood. Blood carries the hormones from the site of secretion to the site of
action.
▪ Exocrine glands contain ducts and hence, the site of synthesis of glands is
same as their site of action i.e. the enzymes produced by the exocrine glands
are not dependent on blood to carry them to their respective site of action.
▪ e.g. salivary gland, tear gland, etc.

WHAT ARE HORMONES?
• Hormones are secreted from their source directly into the blood.
• Blood carries the hormone to the target cells which respond to it.