PNB 2264 Lecture Notes - Lecture 18: Adrenal Gland, Pancreatic Islets, Endocrine Gland
17 Dec 2018
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Document Summary
Simple - endocrine gland controls release of its own hormone. Raises plasma ca++ concentration by breaking down bone. Lowers plasma ca++ concentration by building bone. Alpha cells secrete glucagon (raises blood glucose levels) Beta cells secrete insulin (lowers blood glucose levels: glucose enters via a transporter broken down to produce atp, atp accumulation stops k+ entry, voltage gated ca++ channels open, insulin is released. Sympathetic - input to beta cells inhibits insulin release (we don"t want glucose levels to lower during fight or flight response) Parasympathetic - input to beta cells stimulates insulin release (vagus) Hormones may regulate other hormones at multiple levels. Ex) thyroid hormone alone gives a small amount of fatty acid released. Epinephrine alone gives a bigger amount of fatty acid released. Epinephrine and thyroid hormone gives a very large amount of fatty acid release. Permissiveness - hormones may modulate effect of other hormones. Regulating the secretion of other hormones (using releasing and tropic hormones)
