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BioSciences https://www.youtube.com/watch?v=kkGeOWYOFoA https://vimeo.com/9953368
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BioSciences Copyright Notice Figures and images indicated by KLES are taken from the subject textbook R B Knox, P Y Ladiges, B K Evans and R Saint, Biology, An Australian Focus 4th Ed, McGraw-Hill, 2009, with permission of the publisher. Diagrams and images without that designation are © Geoff Shaw, or are from public domain sources as indicated.
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BioSciences Nerves and Hormonal Regulation Professor Geoff Shaw School of BioSciences g.shaw@unimelb.edu.au Ref: KLES 4 th Ed: Chapter 27, esp pp 637-643, Ch 28, esp pp 661-663 5 th Ed: Chapter 28, esp pp 680-688, Ch 29, 706-709 Resources on LMS
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BioSciences Internal communication Nerves Hormones
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BioSciences Nerves fast point-to-point signalling action potential synapses and neurotransmitters KLES5 fig 29.1a
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BioSciences Nerves and action potentials trans-membrane –ion channels (passive – diffusion) –ion pumps (active) http://ed.ted.com/lessons/how-do-nerves-work
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K+K+ Na + K+K+ K+K+ V V Resting -70 mV (inside vs outside) - + Na / K pump maintains concentration gradient of ions membrane potential Na+ / K+ ion pump voltage gated channels
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K+K+ Na + K+K+ K+K+ V V Depolarised (+ 40 mV) - + V small depolarisation transient opening of voltage dependent Na + channels influx of Na + surge of depolarisation. depolarised ?
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K+K+ Na + K+K+ K+K+ V V Repolarised (- 70 mV) - + V large depolarisation transient opening of voltage dependent K + channels eflux of K + membrane repolarisation K + channel closes voltage gated channels refractory – cannot respond for short period V Na + depolarisation propagates to adjacent Na+ channels
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K+K+ Na + K+K+ K+K+ V V Resting -70 mV - + Voltage gated channels closed Na / K pump restores resting concentration gradient of ions membrane potential restored to normal ready to respond to another signal…
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BioSciences Nerves Model of propagation.
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BioSciences Nerves synapses –junctions neurons muscle neurotransmitter –released when AP reaches synapse –triggers AP in next cell
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BioSciences Hormones and the Endocrine System
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BioSciences
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hormones Chemical messengers released from endocrine glands into blood Receptors on target organs –specific A Receptor hormones
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BioSciences Hormone action KLES5-fig 28.2
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BioSciences Chemical messengers endocrine –circulate in blood to distant target paracrine –released to act on adjacent cells autocrine –action on cell releasing the chemical
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BioSciences Endocrine system http://en.wikipedia.org/wiki/File:Endocrine_central_nervous_en.svg Don’t try to memorise these next few wikipedia figures – the key point is the endocrine system is complex and affects all body systems
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BioSciences http://en.wikipedia.org/wiki/File:Endocrine_Alimentary_system_en.svg
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BioSciences http://en.wikipedia.org/wiki/File:Endocrine_reproductive_system_en.svg
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BioSciences http://en.wikipedia.org/wiki/File:Calcium_regul ation.png http://en.wikipedia.org/wiki/File: Endocrine_caclcium_en.svg
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BioSciences http://en.wikipedia.org/wiki/File:Endocrine_miscelaneous_en.svg
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BioSciences Homeostasis: blood glucose Food glucose+O 2 CO 2 +H 2 O absorption storage transport glucose + glucose +… glycogen glycogen glucose +… release metabolism storage absorption gycogenolysis transport
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BioSciences Homeostasis: blood glucose 4.5 mmol/L eat chocolate rapid absorption glucose metabolised… eat chocolate rapid absorption If no “feedback” regulation…. (…diabetes…) time blood glucose
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BioSciences Insulin and glucagon peptide hormones made by islet cells in pancreas glucose GLYCOGEN Liver cells blood INSULIN GLUCAGON http://en.wikipedia.org/wiki/Islets_ of_Langerhans
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BioSciences Homeostasis: blood glucose 4.5 mmol/L eat chocolate bar With “feedback” regulation…. (normal) time blood glucose high glucose insulin insulin glucose stored in glycogen low glucose glucagon glucagon glucose released from glycogen
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BioSciences Multiple regulatory mechanism… endocrine: –insulin –glucagon –adrenaline –cortisol, … behavioural –hunger eating –satiety fasting –activities burn off sugar lethargy, to conserve sugar etc etc etc…
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Hypothalamus and pituitary sphenoid bone posterior pituitary hypothalamo- pituitary portal vessels anterior pituitary hypothalamus neuro-secretory nerves http://commons.wikimedia.org/wiki/File:Vertebrate-brain-regions.png neurosecretions released in the hypothalamic capillary bed are carried by the portal vessels to the pituitary capillary bed
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BioSciences
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liver Growth Hormone in adults GH hypothalamus pituitary brain + - Somatostatin GHRH fat cells (adipose tissue) IGF1 (Insulin-like Growth Factor 1) - muscle + lots of other tissues GH
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BioSciences Birth, an example of a non-homeostatic processes contractions stretch cervix Pituitary gland uterine contractions oxytocin release neural reflex Ferguson Reflex
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BioSciences What do I expect you to learn from this lecture? internal regulation and coordination via nerves and hormones mechanism of nerve conduction chemical messengers – endocrine, paracrine and autocrine hormone action via specific receptors hypothalamo-pituitary axis examples of endocrine pathways
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BioSciences
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chase up the drugs/hormones/peptides from ACC into sport Among the products offered for sale are CJC-1295, GHRP-6 and Hexarelin - all identified by the ACC and ASADA as being among the principal peptides "misused in both professional sports and the broader population". demonstration nerve – row of students polarised raised arm == voltage etc… add in synaptic comm etc… hormones and blood pressure ACE inhibitors & snake venom… http://www.fasebj.org/content/18/3/421.1.full http://www.sciencedirect.com/science/article/pii/S026240791261 1713http://www.fasebj.org/content/18/3/421.1.full http://www.sciencedirect.com/science/article/pii/S026240791261 1713
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