CSB336 – Lecture Week 3 PDF

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Complete lecture notes including notes provided plus additional notes taken during attendance at lecture.
Course co-ordinator Stephen Bartlett...

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CSB336&–&Lecture&Week&3& & Endocrine)System) ) Glands) & Exocrine)glands) Endocrine)glands) Ducts& Ductless& Numerous& Produce&hormones& Mucous,&sweat,&Oil,&saliva& Secreted&directly&into&extracellular&space& Bile&duct&in&the&liver& Transported&by&blood&or&lymphatic&fluid& Pancreas& Pituitary/thymus& & Thyroid/parathyroid& & Adrenal/pineal& & • Some&organs&can&be&both&–&produce&hormones&as&well&as&exocrine&products& o Pancreas& o Testes& o Hypothalamus& & & & & & & & & & & & & & & & & & & & & & & & & & & & &

& Hormones) • Chemical&messengers&released&to&the&blood&to&be&transported&throughout&the&body& à&influence&metabolic&activities&of&the&cells.& o =to&excite& • Types&of&hormones& o Steroids& § Corticosteroids& § Sex&hormones&–&androgen&&&oestrogen& o Amino&acid&based&/&proteins& § Form&structural&material&and®ulators&of&function.& • Hormone&release& 1. Humeral& 2. Neural& 3. Hormonal& • Hormones& o A&hormonal&stimulus&typically&produces&one&or&more&of&the&following&changes& 1. Changes&in&plasma&membrane&permeability&&/or&electrical&state.& (opening&and&closing&ion&channels)& 2. Synthesis&of&proteins&or&certain®ulatory&molecules&such&as& enzymes&within&the&cell& 3. Enzyme&activation&or&deactivation& 4. Induction&of&secretory&activity& 5. Stimulation&of&mitosis& o Travel&everywhere&within&the&body&but&only&affect&specific&tissue&cells& § target&cellsà& • require&receptor&cells&–&on&plasma&memebrane&or&within&the& cell&so&that&the&hormone&can&bind& ) Homeostasis)and)the)Endocrine)System) • Requires&3&components& 1. Receptor& o Monitors&(eg&temp,&BGL)& o Responds&to&stimuli& o Input&–&sends&info& o Afferent&pathway& 2. Control¢re& o Interprets&info&sent&by&receptor& o Provides&info&re&desired&levels&–&hypothalamus&–&thermostat& o Relays&the&info&to&à& 3. Effector& o The&means&for&the&control¢res&response&to&the&variable& o Output& o Efferent&pathway& & à&feedback&mechanisms& &

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Feedback&mechanisms& & o Negative& § Shuts&off&or&reduces&the&intensity&of&the&original&change& o Positive& § less&common&and&harder&for&body&to&control& § Eg&childbirth&–&contractions&trigger&oxytocin&release&à&increase&force& of&contractions& § Clotting&cascade&à&platelets&attract&more&platelets&à&clot& § Increase&BGL&stimulates&& • Release&of&insulinà&uptake&of&blood&glucose&by&the&cells&à& facilitates&glycogenesis&(glucose&à&glycogen)& • Once&BGL&normal,&insulin&no&longer&required&à&stimulus& diminishes& § Decrease&in&BGL&stimulates& • Release&of&glucagon&by&pancreas&into&blood&à&causes&liver&to& release&its&storage&of&glycogen&as&glucose&(glycogenolysis)& &

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& & & & Glands&–&important&ones&for¶medics& & • Hypothalamus& • Pituitary& • Thyroid& • Adrenal& • Pancreas& &

Hypothalamus&and&Pituitary&gland.& • Antidiuretic&hormone&(ADH)& o Avoids&dehydration&or&water&overload&by&targeting&kidney&tubules& § Made&by&hypothalamic&neurons&and&stored&in&posterior&pituitary&gland& o Stimulated&by& § ⇑&osmolarity&of&blood& § ⇓&blood&volume& § pain& § nicotine/morphine/barbiturates& o inhibited&by& § adequate&hydration&of&the&body& § ETOH& & Thyroid&Gland&–&sits&under&cricoid,&top&of&trachea& • Affects&basal&metabolic&rate& • Affects&oxygen&consumption& • Enhances&effects&of&SNS& • Promotes&breakdown&of&glucose&to&be&stored&as&glycogen&in&the&liver& • Promotes&normal&functioning&of&the&heart& • Promotes&normal&growth&and&maturation&of&skeleton& • Encourages&gastric&motility&and&tone,&⇑&secretion&of&digestive&juices& • Promotes&aspects&of&the&reproductive&and&integumentary&system& & Adrenal&/&suprarenal& • Kidneys&& o Stimulated&by&RAAS&à&⇓&blood&volume&or&BP& o Water&reabsorption&accompanies&Na+&à&⇑&BP& • Body&Cells& o Promotes&gluconeogenesis& o Energy&metabolism& o Protein&catabolism& • Sympathetic&Nervous&System&(SNS)& o ⇑&HR& o ⇑&Metabolic&rate& o causes&vasoconstriction&à&⇑&BP.& & Suprarenal&Glands& • Exocrine&glands&that&sit&on&top&of&each&kidney& • Each&has&a&medulla&and&surrounded&by&a&cortex& • Medulla&à&noradrenaline&&&adrenaline& • Cortex&à&other&hormones&necessary&for&fluid&and&electrolyte&balance&–&cortisol&&& aldosterone& • Cortex&à&sex&hormones& & & &

Pancreas& • Mixture&of&endocrine&and&exocrine&gland&cells& o Islets&of&Langerhans& § Alpha&cells&secrete&glucagon& • Glycogenolysis& • Gluconeogenesis& § Beta&cells&secrete&insulin& • ⇑&glucose&transport&into&the&cells& • ⇑&liver&glycogen&levels& • ⇓&blood&glucose&concentration&toward&normal& & & Disorders)of)the)endocrine)system) & WATCH)2x)VIDEOS)ON)LECTURE)SLIDES) & Type&2&Diabetes&=&non&insulin&dependent&diabetes&mellitus&(NIDDM)& • gestational& • insulin&resistance& • abnormal&insulin&secretions& • overproduction&of&glucose& • 80-90%&of&diabetics& • often&obese& • strong&genetic&composition& & & & & & & & & & & & & & & & & & & & & & &

Management& o Type&1& § Insulin&injections& § Exercise& § Diet®ulation& o Type&2& § Insulin&injections& § Hypoglycaemic&medications& § Exercise& § Diet®ulation& & Diabetic)emergencies) ) 1. Hypoglycaemia& o Causes& § Type&1&diabetic& § Overdose&of&insulin& § Insulin&admin¬&followed&by&a&meal& § Recent&change&in&diabetic&meds& § Overexertion& § Alcoholism& § Liver&disease& § Cancer& § Sepsis& § Hypothermia& § Adrenal&gland&dysfunction& o Common&presentation& § Tachycardic&with&bounding&pulse& § Irritability&/combative& § Pale&cold&clammy& § BGL&...