BIOL 460L 1st Edition Lecture 26 Outline of Last Lecture I Blood Flow II Regulation of Blood Flow in ANS III Paracrine Regulation of Blood Flow IV Autoregulation Outline of Current Lecture I Blood Pressure a Hypertension II Respiratory System a Respiration b Lung c Diaphragm d Boyle s Law Current Lecture Blood Pressure 1 Squeeze a Upstream pressure increases b Downstream pressure decreases 2 Squeeze caused by resistance vessels arterioles 3 Arterial BP Cardiac Output PR 4 Long term BP regulated by kidneys regulate blood volume and sympathoadrenal system 5 Short term BP regulated by baroreceptor reflex a Orthostatic hypotension b Stand quickly and get dizzy c Slow baroreceptor reflex makes it worse d Baroreceptors aortic arch carotid sinus where carotid branches e Baroreceptors are constantly generating APs f Higher pressure more APs g Send sensory information to medulla vasomotor center vasoconstriction dilation and cardiac center heart rate contractility h Beta blockers prevent this reflex syncope pass out 6 Sphygmomanometer blood pressure cuf a Measured in mmHg b Listening for Sounds of Kortkof 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 c d e f Listen at Brachial Artery Increase in pressure above systolic pressure about 140mmHg Squeeze brachial artery shut no sound Pressure decreases until it s just below systolic pressure every systole produces a surge of blood first sound of kortkof g Sound disappears diastolic pressure 7 Hypertension a High blood pressure b 1 5 of Americans c Secondary high BP as a result of a known cause ex atherosclerosis of renal artery d Primary essential Idiopathic poorly understood cause e 120 80 or less no hypertension f Treating hypertension i Reduce stroke volume thiazide diuretic ii Beta 1 blocker slows heart rate and contractility decreases iii Lose weight which drops blood vessel length iv Vasodilators block alpha 1 receptors ACE inhibitor no angiotensin II less aldosterol Respiratory System 1 Respiration a External exchange of respiratory gases between air and blood breathing movements exchanged via simple difusion b Internal exchange between blood and tissues c Cellular metabolic pathways that use oxygen and release CO2 2 Lung a Alveoli 0 25 0 5mm b Type 1 alveolar cells more common i Simple squamous very thin ii Air blood barrier respiratory membrane iii Gases must cross barrier for exchange iv Endothelium of capillary basement membrane of capillary basement membrane of alveolus and type 1 alveolar cells v 2 microns in thickness c Type 2 alveolar cells less common i Secrete surfactant surface acting agent ii Surfactant composed of phospholipids and hydrophobic proteins iii Must have thin film of water on inner surface of alveolus O2 must dissolve before difusing across air blood barrier iv Surfactant prevents sides of alveolus from sticking because of water v Respiratory distress syndrome 1 Hyliane membrane disease 2 Type 2 alveolar cells not secreting surfactin 3 Great risk in immature infants d Respiratory Zone i Region of lung where exchange occurs ii Alveoli plus respiratory bronchioles smallest e Conducting zone i Nasal cavity and mouth ii Pharynx iii Larynx opening called glottis iv Trachea v R and L primary bronchi vi Secondary and third bronchi vii Bronchioles form bronchiole tree viii Terminal bronchioles lead to respiratory bronchioles ix Warm moisten and filter are going into lungs 3 Diaphragm a Divides coelom into thoracic and abdominopelvic cavities b Layer of muscle c Media stinum heart thymus etc separates thoracic cavity into R and L pleural cavities d Airspace in lungs intrapulmononic space e Surface of lungs serous membrane secretes serous fluid to reduce friction f Serous membrane in lungs visceral pleura g Serious membrane in walls of pleural cavities parietal pleura h Intrapleural space potential space because visceral and parietal pleura always in contact and connected via hydrogen bonds 4 Boyles Law a P 1 V b Average atmospheric pressure 760 mmHg c Inhalation i Contract inspiratory muscles diaphragm ii Increases volume iii Decreases pressure 757 mmHg iv Air moves from high to low pressure d Exhalation i Expiratory muscles rather unimportant in normal breathing ii Mostly elastic recoil iii Volume down pressure increases to 763 mmHg iv Table 16 1 intrapleural pressure always lower than intrapulmonic pressure meaning lungs can never completely collapse v Collapse 1 Only in pneumothorax 2 Air in intrapleural space 3 Gunshot wound stab wound scuba