BIOL 460 1st Edition Lecture 24 Outline of Last Lecture I Dissolution of Clots II Anticoagulants III Cardiac Output IV Effects of Stroke Volume a End diastolic volume b Total peripheral resistance c Contractility of Myocardium d Frank Starling Law V Venous Return Outline of Current Lecture I Exchange of Fluid between Capillaries and Tissue a Starling Forces b Edema II Regulation of Blood by Kidneys a ADH b Aldosterone c Renin secretion Current Lecture 1 What affects venous return a Change in pressure in veins i Venules 10mmHg ii Superior and inferior vena cavae 0mmHg iii P 10mmHg b Skeletal muscle pump pushes blood toward heart c Pressure difference between thoracic cavity and abdominal cavity i Exhale decreases thoracic pressure pulling blood to heart ii Doesn t work the other way during inhale because valves prevent backflow Exchange of Fluid between Capillaries and Tissue 1 Fluid movement across walls of systemic capillaries filtration 2 Result of beating heart and pressure These 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 3 Fluid pushed into surrounding tissues 4 Cells and proteins cant filter everything else can 5 Starlings forces forces that cause filtration a Fluid out fluid in filtration b Pc i Pi p filtration i c capillaries ii osmotic pressure iii i interstitial fluid iv p plasma v P pressure c Plasma has a lot of solutes plasma proteins d 37mmHg 0 1mmHg 25mmHg 11 mmHg filtration arteriole e 17mmHg 0 1mmHg 25mmHg 9 mmHg filtration venue f 85 of fluid moves into interstitial fluid the moves back into blood g 2L day 15 stays in interstitial fluid returned to blood via lymphatic system h Edema excess accumulation of tissue fluid 5 causes i Hypertension raises Pc raises value of fluid out component ii Venous obstruction increases upstream pressure to increase Pc upstream iii Leakage of plasma proteins into tissues raises i causing outward component of Starling s forces inflammation and allergies have a similar effect iv Decreased plasma proteins drops p inward component drops can decrease by having protein deficient diet liver manufactures plasma proteins v Obstruction of lymphatic drainage elephantiasis parasitic nematode Regulation of Blood by Kidneys 1 ADH antidiuretic hormone a Diuretic anything that promotes urine formation b Produced by the centers of hypothalamus supraoptic and paraventricular centers c Passed to neurohypohphysis via hypothalamic neurohypophyseal tract d Enters bloodstream e Target is kidney i 180L filtrate day ii 85 reabsorbed automatically iii 15 under hormonal control 27L iv ADH aids in reabsorbing 15 f Osmoreceptors in hypothalamus which detect changes in osmolality of plasma i Will go up for two reasons 1 Dehydration 2 Excessive salt intake ii Increase in osmolality triggers neuroendocrine reflex leas to exocytosis of ADH causing kidneys to reabsorb more water from filtrate iii Also acts on thirst sensors feel sensation of thirst g Absence of ADH large amounts of dilute urine 2 Aldosterone a Low salt low blood volume condition b Promotes retention of salt when salt intake is low c Causes water excretion leads to low blood volume d Retnetio of salt leads to indirect retention of water osmolality up ADH up water up e Increases blood volume without diluting blood 3 Kidneys contain juxtaglomerular apparatus secretes Renin a Low blood volume kidneys not getting enough blood at a high enough pressure to produce filtrate properly b Granular cells of JGA secrete renin into blood c Renin converts angiotensinogen angiotensin I plasma protein produced by liver d Angiotensin ACE Angiotensin II e ACE angiotensin converting enzyme f AII raises blood pressure and blood volume negative feedback for renin g Function of Angiotensin II i Powerful vasoconstrictor raising BP ii Causes adrenal cortex to secrete aldosterone mineralocorticoid iii Stimulates thirst centers
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