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Biology: Endocrine System (NOTES) by Srikrshna P | Helpline for ICSE Students (Class 10) The Endocrine System Glands are modified epithelium which produces certain secretions. TYPES OF GLANDS: Exocrine Gland/Duct Gland Secretions of these Glands are carried to the site of action through fine ducts. E.g.: Salivary Gland Endocrine Gland/Ductless Gland Secretions of these Glands are carried to the site of action through blood. E.g.: Thyroid Gland Heterocrine Gland/Dual Gland These Glands are both Exocrine and Endocrine in function E.g.: Pancreas [Insulin-ENDO ; Pancreatic juice-EXO] Secretions of Endocrine Glands-HORMONES HORMONES: Special chemicals secreted by Endocrine Glands, which are directly poured into the BLOOD and are carried to the site of action, called Target Organ. CHARECTERISTICS OF HORMONES: o o o o o o They are Proteins, specific in function and specific in target Secreted in LOW concentration, if in excess it is excreted through urine Hypo or Hyper secretion causes diseases Hormones act as chemical messengers. They are secreted by living cells/tissues or organs called glands. They are secreted in very small quantities by glands. They act upon specific cells, tissues, or organs called the target sites. They are generally slow in action, but have long lasting effects. They either accelerate or inhibit a reaction. PITUITARY GLAND (A.K.A MASTER GLAND) Location: Below Hypothalamus in the Forebrain. Pituitary Gland id divided into 3 lobes: o Anterior Lobe o Inter-mediate Lobe o Posterior Lobe ANTERIOR PITUITARY LOBE: o Some of the Hormones of Anterior Pituitary Lobe are called Tropic Hormones o Tropic Hormones: Hormones which stimulates other Endocrine Glands to produce their secretions. 1 Visit us @ http://icsehelpline101.wordpress.com | Connect @icsehelpline101
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