PHYSCI M140 Lecture Notes - Lecture 3: Posterior Pituitary, Adrenergic Receptor, Pituitary Gland
18 Oct 2016
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Document Summary
Two different types of receptor systems: membrane receptors and intracellular receptors: membrane receptors: target cell. Hormone (hydrophilic) binds to receptor on outside of cell, transmits information to the inside (2nd messengers inside: ca, camp) that affects cell function. Receptor can be bound to channel on membrane changing electrical potential. These effects can be extremely fast: within seconds small change. Ex. under acute/stressful situations, adrenal glands secrete adrenaline (largely made up of epinephrine, a hydrophilic hormone derived from an amino acid (cid:383)1-adrenergic receptor on smooth muscle in blood vessel. Causes rapid increase in ca in the cell, causing smooth muscles to contract blood pressure goes up. When epinephrine binds (cid:384)-adrenergic receptor on heart cell, causes camp and heart rate to go up. Whole response is called (cid:281)flight or fight(cid:282) -happens within seconds of frightful experience. Hormone (lipophilic like steroids) must go inside of cell membrane to bind to receptor. These receptors function by regulating cellular gene expression.
