PSYC1011 Lecture Notes - Lecture 7: Negative Feedback, Sympathetic Nervous System, Adrenocorticotropic Hormone

• School: UNSW, UNSW Sydney
• Department: Psychology
• Course: PSYC1011
• Professor: All

Document Summary

Hormones: chemical messengers generally synthesised by specialised glands carried by the circulation to target tissues and organs. Hypothalamic pituitary adrenal axis thyroid axis: adrenal axis, gonadal axis. Differences between neural and endocrine signalling: neural communication. Info passed from one cell to the next: works like a telephone system, rapid - millisecs, endocrine/hormonal communication, works like radio or tv broadcasting, slower - measured in minutes and seconds, analogue messages - graded strength. I. e phenylalanine: tyrosine, tryptophan, by decarboxylase enzymes, release similar to peptide hormones, packaged into secretory vesicles, released by exocytosis from cell membrane. Mechanisms of hormone signalling: endocrine or neuroendocrine cells release hormones into the bloodstream, paracrine hormones act locally on nearby cells, autocrine signals provide feedback to the cell from which they were released. Hormones alter cellular function: by promoting the proliferation, growth and differentiation of cells, modifying activity of the cell, altering what a cell is producing, affecting the firing of a cell.