BIOL 460 1st Edition Lecture 25 Outline of Last 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 Outline of Current Lecture I Regulation of Blood by Kidneys a ANP II Blood Flow III Regulation of Blood Flow in ANS IV Paracrine Regulation of Blood Flow V Autoregulation Current Lecture Regulation of Blood by Kidneys 1 Atrialnatriuretic Peptide ANP a Natri salt uresis urine production b Aldosterone antagonist c Excretion of salt and water in equivalent amounts d Secreted by L atrium some right as a result of increase dblood volume e Strectch receptors in atria aorta and carotid artery f Causes secretion of ANP g Stretch receptors also cause lower ADH secretion h Antagonizes Angiotensin II Blood Flow 1 Dependent on P pressure change a Mean arterial pressure MAP 100mmHg 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 b Blood pressure in right atrium 0mmHg c P 100mmHg drives blood through blood vessels 2 Blood flow proportional to P 3 BF P PR 4 PR peripheral resistance a Resistance to blood flow b Caused by i Length of blood vessels ii Viscosity of blood iii Diameter of blood vessels r radius c PR LV r4 5 Pouiselle s Law 4 a BF Pr 8 LV 6 P mean arterial pressure a 120 80 in normal healthy adult b Systole diastole pulse pressure 40 c MAP diastolic pressure pulsepressure Organ systems are in parallel not in series 1 Not usually one after the next 2 If that was the case vasoconstriction and dilation would have a huge effect downstream 3 Two series a Kidneys hepatic portal b Liver cleans blood Regulation of blood flow by ANS 1 Alpha 1 andrenergic receptors in sympathetic ANS cause vasoconstriction of vessels in skin and viscera 2 Beta 1 receptors speed up heart rate and contractility affecting P 3 Muscarinic cholinergic receptors innervated to vasodilate blood vessels of skeletal muscle IPSP 4 Muscarinic cholinergic receptors slow HR in parasympathetic division of ANS no effect on contractility 5 Parasympathetic innervation to blood vessels of viscera not a huge effect Paracrine Regulation of Blood Flow 1 NO 2 Prostacyclin 3 Causes vasodilation Autoregulation 1 Myogenic control mechanisms a Walls of small arterioles contain stretch recedptors b Receptors are mechanically gated ion channels c Ex vessel supplying kidney and brain i Need relatively constant BP ii Stretch opens ion channel epsp vasoconstriction iii Pressure decreases vessel vasodilates iv Smooth flow of blood to kidneys and brain 2 Metabolic Control Mechanisms a Increase in CO2 b Decrease in O2 c Decrease in pH d Tissue needs adequate blood supply to prevent CO2 buildup e CO2 H2O H2CO3 H and HCO3 f Decrease in pH causes vasodilation to increase blood flow to an organ 3 Reactive Hyperemia a Excess of blood in a body part b Blood pressure cuff example 4 Active hyperemia a CO2 generated very quickly at start of intense exercise b Heart and vessels haven t caught up yet c Causes vasodilation
View Full Document
Unlocking...