BioSciences

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.

BioSciences Nerves and Hormonal Regulation Professor Geoff Shaw School of BioSciences Ref: KLES 4 th Ed: Chapter 27, esp pp , Ch 28, esp pp th Ed: Chapter 28, esp pp , Ch 29, Resources on LMS

BioSciences Internal communication Nerves Hormones

BioSciences Nerves fast point-to-point signalling action potential synapses and neurotransmitters KLES5 fig 29.1a

BioSciences Nerves and action potentials trans-membrane –ion channels (passive – diffusion) –ion pumps (active)

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

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 ?

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

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…

BioSciences Nerves Model of propagation.

BioSciences Nerves synapses –junctions  neurons  muscle neurotransmitter –released when AP reaches synapse –triggers AP in next cell

BioSciences Hormones and the Endocrine System

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hormones Chemical messengers released from endocrine glands into blood Receptors on target organs –specific A Receptor hormones

BioSciences Hormone action KLES5-fig 28.2

BioSciences Chemical messengers endocrine –circulate in blood to distant target paracrine –released to act on adjacent cells autocrine –action on cell releasing the chemical

BioSciences Endocrine system 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 ation.png Endocrine_caclcium_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

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

BioSciences Insulin and glucagon peptide hormones made by islet cells in pancreas glucose GLYCOGEN Liver cells blood INSULIN GLUCAGON of_Langerhans

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

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…

Hypothalamus and pituitary sphenoid bone posterior pituitary hypothalamo- pituitary portal vessels anterior pituitary hypothalamus neuro-secretory nerves neurosecretions released in the hypothalamic capillary bed are carried by the portal vessels to the pituitary capillary bed

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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

BioSciences Birth, an example of a non-homeostatic processes contractions stretch cervix Pituitary gland uterine contractions oxytocin release neural reflex Ferguson Reflex

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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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://