BIOL 111 Lecture Notes - Lecture 17: Pedicellaria, Symmetry In Biology, Asexual Reproduction

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Biol 111 lecture 17 hormones/arthropoda/deuterostomes: chemical messengers, secreted by endocrine cells, hormones are distributed by blood, bind to target cell receptors (target specificity depends on receptor equipment of cells) How do hormones work: hormones act by, affecting the expression of a gene, altering the activity of an existing enzyme, changing permeability of a cell membrane. Relating to arthropods: ptth (brain hormone (prothoracicotropic hormone); peptide) stored and produced by the brain (neurohormone, production influenced by environmental cues controls activity of prothoracic gland. Ecdysone (steroid) produced by prothoracic gland secreted into hemolymph target cells = epidermis response = ecdysis brain responds by shutting off ptth hormone (negative feedback) Endocrine: hormones, diffuse via blood, slower, long term. Nervous system: action potentials, electrical signals along neurons, quicker, short term. Both systems work together neurons trigger hormone release e. g. , neurons in hypothalamus make hormones the posterior pituitary gland hormones feed back onto nervous system. Hypothalamus/posterior pituitary gland: neurohormones of ppg, adh (anti-diuretic hormone) released by.