HNF 462 1st Edition Lecture 19Outline of Last LectureI. Second MessengersII. Calcium as a Second MessengerIII. Muscle ContractionIV. Other Functions of CalciumV. Muscle RelaxationVI. Effects of Physical Activity and Weight Loss on Diabetic PatientsVII. MyoglobinVIII. Function of MyoglobinOutline of Current LectureI. Electrolyte ImbalanceII. Neurotransmitter SynthesisIII. Serotonin and Melatonina. Functionsb. SynthesisIV. Catecholaminesa. Functionsb. SynthesisV. Histamine SynthesisVI. Neurotransmitter Synthesis- Vitamin Dependence SummaryVII. Acetylcholine (ACh)a. Functionb. SynthesisVIII. Myelina. Formationb. SynthesisThese 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.IX. Blood Brain Barrier (BBB)Current Lecture: Nutrition and Neurotransmitters1. Electrolyte Imbalancea. Can cause involuntary muscle spasms/crampsb. Crampers tend to have high sodium concentration in sweat and high sweat ratec. Athletes drink sports drinks with electrolytes to try to maintain electrolyte balance2. Neurotransmitter Synthesisa. Neurotransmitter: chemical that allows signal transmission from neuron to neuroni. Function in similar manner to hormones in that they both bind to receptors, but neurotransmitters function over short distancesb. General Mechanisms: hydroxylation and decarboxylation reactions3. Serotonin and Melatonina. Functionsi. Serotonin: influences mood, vasoconstrictor, platelet function, and controls movement throughout the GI tractii. Melatonin: controls sleep and wake cyclesb. Synthesisi. Starting Point: Tryptophanii. First Reaction: hydroxylation (Vitamin C dep); tryptophan 5-hydroxytryptophaniii. 2nd Reaction: decarboxylation (vitamin B6 dep): 5-hydroxytryptophan 5-hydroxytryptamine (aka serotonin)iv. Serotonin melatonin: requires addition of methyl group1. Methyl Donor is SAM4. Catecholaminesa. Functionsi. Production by adrenal glands and neurons increases in response to stress; prepares the body for fight or flight responseii. Dopamine, Norepinephrine, and epinephrineb. Synthesisi. Starting Point: Tyrosine or Phenylalanine1. If starting with phenylalanine, then phenylalanine is converted to tyrosine by a hydroxylation reactionii. Tyrosine DOPA by hydroxylation reaction iii. DOPA dopamine by decarboxylation reaction (Vitamin B6 dep)iv. Dopamine norepinephrine by hydroxylation (vitamin C dep)v. Norepinephrine epinephrine by addition of methyl group (folate and B12 dependnent)5. Histamine Synthesisa. One step of decarboxylation from histidine histamine6. Neurotransmitter Synthesis- Vitamin Dependence Summarya. Neurotransmitters are synthesized in the neuronb. Serotonin: Vitamins B6 and Cc. Melatonin: Vitamins B6, C, and folate/B12 (indirectly)d. Dopamine: Vitamin B6e. Norepinephrine: Vitamins B6 and Cf. Epinephrine: Vitamins B6, C, and folate/B12 (indirectly)g. Histamine: Vitamin B67. Acetylcholine (ACh)a. Function: carries nerve impulse between synapses; responsible for muscle movement and important in memoryb. Synthesisi. Cholline acetyltransferase produces ACh from acetyl CoA and cholineii. Synthesis affected by choline and acetyl CoA deficiencies8. Myelina. Functions: Protection, insulation, nourishes neurons, and makes depolarization spread farther/quicker down neuronb. Synthesisi. Requires addition of one-carbon unit by donation from SAMii. Deficiency of B12, folate, or B6 will reduce SAM levelsiii. B12 deficiency myelin breakdowniv. Maternal B12 deficiency demyelination in child psychomotor retardation9. Blood Brain Barrier (BBB)a. Special transporters for essential nutrients are needed in order to transport them into the brain tissue because of the presence of the BBBb. Availability to brain is slower than for the peripheral
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