Endocrinology, lecture introducing hormones, paracrines and neurotransmitters
USD Department of Biology
Endocrine Glands
2nd Messengers
Nuclear Receptors
Genetic Regulation
Hormone Synthesis
Receptor Regulation
Hypothalamo-Hypophysial Communication
Tropic Hormones
Neurohypophysial Nonapeptides
Thyroid Axis
Adrenal Axis
Adrenal Medulla
Osmotic-Pressure Balance
Reproductive Endocrinology
Somatic Axis
Growth Factors
Immune Factors
Ca++, PO4 Homeostasis
Pancreatic Hormones
GI Hormones
Guts 'n Brains
Brain Hormones
Endocrine Evolution
Figures for Endocrionology
text:Vertebrate Endocrinology5th Edition - David O. Norris:
Read pages 1-7; 30-45 for this lecture
acronyms    end
I. Introduction to Endocrine Function 			

	A. Endocrines = Hormones are endogenous chemicals produced by glands 

		1. Secreted into the Bloodstream

			a. no ducts

				i. exocrine glands have ducts to the outer surface

					(1) e.g. surface of the skin, lumen of the intestine,
					    uterine cavity

			b. plasma concentration [hormone] = the amount (often in
			    ng/ml) of hormone in the blood

		2. Exocrines, Paracrines, Autocrines, Neurotransmitters

			a. may be similar or identical to hormones but 
			   are not secreted into the blood

			b. Exocrines secreted outside the body

				i. pheromones, sweat, digestive enzymes

			c. Paracrines are secreted into the extracellular fluid

				i. effect adjacent cells

					(1) prostaglandins (PGs), growth factors (GFs),
					    thromboxanes (TX), leukotrienes, opiate peptides

			d. Autocrines are also secreted into the extracellular fluid

				i. effect the cells that secrete them

				ii. Autocrines usually = Paracrines

			e. Neurotransmitters are paracrines secreted into a specific type
			   of extracellular space = synaptic cleft

				i. DA, NE, Epi, ACh, GABA, Glutamate, histamine, glycine...

				ii. neurons which secrete into the blood stream are neurosecretory neurons

					(1) the secretion is a neurohormone

					(2) the synapse with the bloodstream is a neurohemal organ

			f. Growth Factors

				i. paracrine/autocrines which may mediate hormonal effects

					(1) NGF, EGFs, IGFs, PDGF, ILs

		3. Intracellular Endocrine Mediator = 2nd messenger

			a. stimulate cellular function as a result of hormones 
			   binding to membrane receptors

				i. cAMP, cGMP, Ca++, IP3, Calmodulin, protein kinases,
				    Phosphatidylcholine, polyamines, PGs, oligosaccharides

II. Endocrine Glands