01:377:213 Lecture Notes - Lecture 7: Pineal Gland, Thyroid, Adrenal Medulla
13 Mar 2018
School
Department
Course
Professor
Document Summary
Functionally part of the nervous system b: endocrine glands secrete substances directly into extracellular spaces around the gland. Occurs to increase hormones effect: prolonged exposure to high hormone concentration can desensitize target cells to hormonal stimulation, form of downregulation: loss of receptors to prevent target cells from over responding to chronically high hormone levels. Receptors at membrane can be internalized and decrease hormones effects. The main endocrine organs are: pituitary gland, hypothalamus: anatomically part of the brain, secretes hormones and functionally part of endocrine system, thyroid gland, adrenal glands, pineal gland, parathyroid glands, pancreas. Chemicals: hormones regulate the metabolic operations of target cells. Low t4 levels cause sluggishness 15 hour sleeping: whole body metabolism influences synthesis of these thyroid hormones. Feedback system: depressing metabolic rate to some critical value directly stimulates release of tsh, acts of thyroid gland. The secretion increases rate of metabolism: in there is elevation in metabolism, it reduces tsh production and causes metabolism to slow.
