BIO202H5 Lecture Notes - Lecture 8: Ecdysone, Prothoracicotropic Hormone, Pineal Gland
Document Summary
Lecture 8: internal balance (1) photoperiod and size (moult) *diagram* Ecdysone + low jh larva straight to adult. If you increase jh, larval stage happens faster decrease, full molt into adult hood, last larval stage to full adult hood. Larval to adult stage triggered by amount of light communicating with brain through pineal gland and more regions called light rain system or connections. Amount of light in a day stimulates activities of different parts of body. Ptth (prothoracic tropic hormone) connected to different pathways of brain hormone in right light period stimulates prothoracic gland to release ecdysone. When ptth secreted but jh low last final adult stage triggered. Bombyxin stimulates release of steroids stimulation of growth allows them to grow to certain size before they molt (if molt before right size it can be dangerous and detrimental) Myosupressin inhibits ecdysone to prolong larval growth (2) photoperiod and migration. Arctic term annually over 80,000 km.
