Neural CommunicationEndocrine SystemCharacteristics that differ from NeuralBasic PrinciplesPeptide HormonesSteroid HormonesAminesPhysiology 206 1STedition Lecture 29Outline of Last Lecture I. Review for Exam 3Outline of Current Lecture I. Neural CommunicationII. Hormones Current LectureNeural Communication- Instantaneous cut on- Instantaneous cut ofEndocrine System- cell secrete messengers into blood stream- Which then goes throughout the body to target- Doesn’t usually involve cells that are close to eachCharacteristics that differ from Neural- Takes much longer to get to target- When it gets there, it doesn’t get there abruptly- Takes awhile to reach full amplitude- When stop secreting; it lasts in blood stream for awhile- The message is difused- some hormone acts on many diferent cells Hormones- messenger chemicals secreted by endocrine system; which is secreted straight into bloodstream therefore, the Endocrine Glands are also called “ductless glands”- there are instances when the Neural System releases into bloodstream instead of target cells, and they are known as Neuroendocrine and the hormones that release are called Neurohormones.Basic Principles Endocrine Physiology Topics:1.) what controls secretion2.) what efects they have- They are practically important in things that have to be maintained, over long periods of time.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. this is important because in Neural System receptors fatigues or adapts, so they are not good choices for maintaining things Things that are under endocrine control- (total body water; blood/glucose level)- Things that make up endocrine system consists of glands that are not connected or anatomically disconnected, but work as a group because they are held together by circulation. there are hormones that are released, just to control other secretion of other hormones, are called Tropic Hormones Hormones that mainly on things outside endocrine system, called Nontrophic Hormone some endocrine glands, that have more than one cell in them, so they secrete more than one type of hormone. Very common for a hormone to have efect on more than one type of cellHormone Classes:- Determined by Chemical Structure1.) Peptides2.) Steroids3.) Amines Useful grouping because, each class have similarities in how:a.) they are synthesizedb.) what its stored in, if it isc.) how they get secretedd.) how they are transportede.) what it does when it gets therePeptide Hormones- basically small proteins- synthesized for export from cell- synthesis happens on ribosomes, as in active precursors- Get transported through cell in ER- When arrive at Golgi, they get enclosed in membrane, and get stored- When it is stimulated, the packages get released (somewhere between last one and here, get turned into hormones)- All water soluble- they dissolve in plasma with no trouble, and that’s how they travel in blood they do not get into cells because large water soluble- When they get to target cell, there have to be structures on the external surface of the target cells, called receptors, that the hormone can interact with it, and cause cell to do its trick. any cell that doesn’t have receptor, won’t be efected.- If gave a peptide orally, it would be destroyed in stomach, meaning you can’t use them orally, as therapeutic devices.Steroid Hormones- Unlike peptides, they are fat (lipid) fat soluble, meaning they can get into cell; can difuse right across- There is no way for cell to synthesize and store them; so there is not step of storage to wait for stimulus- Instead, when cell gets stimulated then it starts producing steroid, and release them.- When they get to target cell, the membrane doesn’t stop them, so they difuse in , get to nucleus, get to proteins, that bind to steroids to steroid, which get in DNA, which activate genes.- Have specific carrier proteins in plasma, which steroid bind tightly to them, it behaves as if proteins didn’t exist hormones would end up in the walls of gland. (used like taxies)- Remains tied to proteins, until it encounters a place that causes them to release from protein- Because steroid cross membrane easily, and they are not destroyed in stomach, they can be given orally.Amines- Fairly diverse group, so not able to produce a list of properties Characteristics of all Hormones1.) Efective at very low concentrations(10-8 M to 10-12 M)- much more potent, unlike other systems (10-3 to 10-1) Many times more potent- Concentration of hormone in blood stream represents a balance in it bring added of subtracted to blood stream- it almost never means that one is acting more than another one goes up, the other goes up