PHYSIO-s10_09 - 2/21/2010 BIOL 260: Human Physiology Human...

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Unformatted text preview: 2/21/2010 BIOL 260: Human Physiology Human Spring 2010 Spring M, Feb. 22, 2010 Feb. www.smccd.edu/accounts/staplesn/biol260 1. Pre-Lab Writeups: Be sure to prepare before each Monday Lab W riteups Be before each Monday or Wednesday labs (for WHOLE week!)!! or Wednesday – (What? Why? How? are we doing in the lab??) 2. THIS Week: Expt. 7, EMG parts 1 & 2!!! • Nerves Report #2 Due THIS week in lab. • Expt. 4 Lab Data is POSTED under “Additional Materials”. Expt. 3. Midterm 1 study guide IS updated Midterm • Review sessions this week in lab ……. Review …… • Review also on WED. morning, 9:30 AM in 16-204 (Micro/Cell Lab). Review WED. • Work-out ALL short essays!! Know your terms!! REVIEW 1. Describe and diagram the process by which neurotransmitters Describe neurotransmitters are released ffrom axon termini and act on a target cell. rom are released act TODAY: Students should be able to…... 1. Ch. 11: Describe several processes controlled by each branch Describe of the efferent division of the peripheral NS. (autonomic & efferent somatic) somatic) 2. Distinguish the origins, anatomy, & preganglionic and Distinguish anatomy preganglionic and postganglionic signaling (neurotransmitters and receptors) of the sympathetic and parasympathetic branches of the sympathetic of autonomic efferent PNS. autonomic 3. Describe several processes in which sympathetic and Describe parasympathetic iinputs from the Autonomic EPNS exert parasympathetic nputs antagonistic control. antagonistic 1 2/21/2010 B. Long-Term Potentiation Term Potentiation • Sustained changes – In synapses • May be key to learning & memory May processing. processing. – Glu (Glutamate) = main excitatory CNS NT – Glutamate receptors: (CNS) • NMDA receptor channel – (= glutamate agonist) 1)Ca++/Na+ entry blocked by gate and Mg++ ion 2)Needs GLU + depol’n to open (AMPA receptor = glu agonist) Needs depol glu ++ ion, and Ca++/Na+ enter 3)Depol’n ejects Mg 4)Paracrine enhance NT release (presynaptic!!) and !!) upregulates GLU Receptors (postsynaptic!)…….. upregulates Strengthens pathway for the long term!! Long-Term Potentiation Term Potentiation Figure 8-32: 32: Long-term Long term potentiation potentiation ~ Positive feedback cycle: • Glu Ca++ paracrine Ca++ ↑Glu…. 2 2/21/2010 8.8) Nervous Tissue 8.8) Development Development • 100 billion neurons find their 100 target target • Growth cones – Follow growth factors, Follow structural proteins (PM, ECM) structural – Neurotrophic factors – sustain new synapse – "Use it or loose it" Figure 8-33 Figure 8-34 Chapter 11 Efferent Division: Autonomic Efferent and Somatic Motor Control and 3 2/21/2010 Ch. 11 Overview: 1. Efferent peripheral nervous division, and Efferent what it controls what 2. Pathways, receptors, and neurotransmitters 3. Antagonistic controls: sympathetic and Antagonistic parasympathetic (AUTONOMIC EPNS) parasympathetic 4. Control of cardiac, smooth muscle and Control glands in homeostasis glands 5. CNS control of skeletal muscles through CNS neuromuscular junctions (SOMATIC EPNS) neuromuscular 11.1) Autonomic Division: 11.1) Homeostatic balancing Homeostatic • Controls: Visceral Organs…. Controls: Visceral – Smooth & cardiac muscle Smooth – Glands & adipose • Antagonistic branches: – Parasympathetic • "Rest & digest" – Restore body – Sympathetic • "Fight or flight" – Energetic action 4 2/21/2010 Autonomic Division: Autonomic Homeostatic balancing Homeostatic Figure 11-1: Homeostasis and the autonomic division A. Autonomic Control Centers 1. Hypothalamus – Water balance – Temperature – Hunger 2. Pons – Respiration – Cardiac – Vasoconstriction 3. Medulla – Respiration Figure 11-3: Autonomic control centers in the brain 5 2/21/2010 B. Autonomic Pathways: B. Communicate to Body (“visceral”) 1. Coordinates homeostatic responses a) Autonomic Autonomic b) Endocrine b) Endocrine c) Behavioral c) Behavioral 2. Blood pressure 2. 3. 4. 5. 6. Osmolarity Tonic regulation Antagonistic control Receptor-directed response Autonomic Pathways: Autonomic Communicate to Body Communicate Figure 11-2: The hypothalamus and brain stem (pons, medulla) 2: hypothalamus and brain initiate autonomic, endocrine, and behavioral responses 6 2/21/2010 C. Autonomic Pathways: C. Two Efferent Neurons Two 1. CNS 2. Preganglionic neuron 3. Ganglion 4. Postganglionic Postganglionic neuron neuron 5. Target tissue Figure 11-4: Autonomic pathways D. Comparison of sympathetic D. & Parasympathetic Pathways Parasympathetic DIFFER BY: DIFFER • Neurotransmitters • Receptors short (near (near CNS) CNS) long (near (near target) target) long short Figure 11-7: Sympathetic and parasympathetic pathways 7 2/21/2010 11.2) Parasympathetic 11.2) Parasympathetic Branch: “Rest and Digest” Branch: 1. Preganglionic neurons (longer) a) Originate in 1) Brain stem – cranial nerves, Vagus Nerve Brain cranial Vagus 2) Lower spinal cord (sacral) b) NT released: Acetylcholine (ACh) 2. Ganglion (close to target) a) Near target b) Nicotinic cholinergic (nACh Receptors) on PSM – ICR (Na+, K+): net Na+ entry depolarization ICR – Upregulated by overexposure to Nicotine!!! 3. Postganglionic neuron (shorter) • NT: ACh onto mACh Receptors (muscarinic) Figure 11-5: Autonomic sympathetic and parasympathetic pathways 8 2/21/2010 Actions of Parasymp. Branch Actions Parasymp 1. Constricts Constricts a) Pupil a) b) Bronchioles 2. Slows heart 3. Stimulates a) Digestion b) Insulin release c) Urination d) Erections 11.3) Sympathetic Branch: 11.3) Sympathetic Branch: “Fight or Flight” 1. Preganglionic neuron (shorter) a) b) c) Short Origin: spinal cord (aorta; thoracic & lumbar) NT: cholinergic (nACh-R) for ACh R) ACh 2. Ganglia (close to CNS) a) Sympathetic chain b) Near spinal cord/CNS 3. Postganglionic neuron (noradrenergic; AdrR) AdrR a) Long b) NT: adrenergic receptors (norepinephrine) – GPCR NT: 1) Alpha (smooth muscle contraction, stim. secretion) – common, NOR>EPI. (smooth stim common, NOR>EPI. 2) Beta 1 (heart stim.; Beta Blockers HR BP) – NOR=EPI. (heart stim.; HR BP) 3) Beta 2 (not innerv’d! smooth muscle relax, Blood vessels) - EPI>NOR. not innerv 9 2/21/2010 Actions of Sympathetic Branch: Actions Stimulatory & Inhibitory Stimulatory Inhibitory 1. 2. 3. 4. Pupil dilation Salivary proteins/mucus Heart beat & volume Dilation a) Blood vessels b) Bronchioles 5. Catecholamine release (TYR) release a) Norepinephrine (NT), Norepinephrine b) Epinephrine (hormone), b) Epinephrine – [Dopamine (inh. NT) – CNS] NT) 1. Digestion 2. Salivation Salivation - watery 3. Pancreas Pancreas secretion secretion 4. Urination 6. Fat breakdown 7. Ejaculation A. Adrenal Medulla: A Modified A. Adrenal Modified Sympathetic Ganglion Sympathetic • Sympathetic stimulation of Adr. Med.: Sympathetic Adr 1. Catecholamine release into blood a) b) Epinephrine Norepinephrine 2. Travel to: a) Multiple targets b) Distant targets (neuroHORMONES!!) 10 2/21/2010 A Modified Sympathetic Ganglion AdrenAl MedullA: Figure 11-10: The adrenal medulla • Varicosities B. Synapses in Autonomic B. Nerves Nerves – swellings at swellings neuroeffector jxns. neuroeffector • NT released to ECF – Dilute, slow – may not reach may target target • No cleft • Impact: – Large area – Slow acting – Long duration Figure 11-8: Varicosities of autonomic neurons 11 2/21/2010 C. Mechanism: Norepinephrine C. Release and Recycling Release Figure 11-9: Norepinephrine release at a varicosity of a sympathetic neuron 9: varicosity MAO inhibitors = treat MAO depression, Parkinson’s depression, Review of Efferent Pathways: Review Motor & Autonomic Motor Figure 11-11: Summary of efferent pathways 12 2/21/2010 11.4) Somatic Motor Division: 11.4) Somatic Controls Skeletal Muscles 1. 2. 3. 4. Body movement Appendages Locomotion Single neuron Single a) CNS origin a) b) Myelinated Figure 11-11: 11: Summary of efferent pathways 5. Terminus Terminus a) Branches a) b) Neuromuscular junction A. Neuromuscular Junction: A. Overview Overview 1. Terminal boutons 1. Terminal boutons 2. Synaptic cleft a) Matrix b) AChE c) Hold together 3. Motor End Plate a) b) – On muscle High [nACh-R]’s Always excitatory!! http://www.blackwellpublishing.com/matthews/nmj.html 13 2/21/2010 Neuromuscular Junction (NMJ) Somatic motor neuron The neuromuscular junction Schwann cell sheath Axon terminal Mitochondria Muscle fiber Terminal bouton Motor end plate Synaptic v esicle ( ACh) Presynaptic membrane Synaptic cleft Figure 11-12: Anatomy of 12: the neuromuscular junction the Nicotinic ACh Receptors Postsynaptic Membrane = modified into MEP!! • NMJ = axon terminals, motor end plates on the muscle membrane, and Schwann cell sheaths. membrane, • The MOTOR END PLATE iis a region of muscle membrane s The MOTOR that contains high concentrations of ACh Receptors. that B. NMJ: Mechanism of Signal B. Conduction Conduction 1. Axon terminal a) AP signals b) ACh release 2. Motor end plate a) b) c) d) 2 ACh bind ACh opens cation channel opens cation Na+ influx Membrane Membrane depolarized depolarized http://bcs.whfreeman.com/thelifewire/ content/chp44/4403s.swf 3. Stimulates fiber Stimulates contraction contraction 14 ...
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This document was uploaded on 03/18/2010.

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