BIOL 252 1st Edition Lecture 21 Outline of Last Lecture I Capillary Exchange II Respiratory System III Ventilation IV Expiration is easy Outline of Current Lecture I How significant is pulmonary elasticity II Ventilation III Resistance to Airflow IV Respiratory Volumes V Restrictive Pulmonary Disorders VI Obstructive Pulmonary Disorders VII Gas exchange VIII Gas transport IX Urinary System X Kidney Function XI Nitrogenous Wastes XII Nephron Current Lecture I II III How significant is pulmonary elasticity a Pneumothorax or hemothorax is compromise of pleural membranes b Unopposed pulmonary elasticity shrinks lungs and expands pleural cavity c Two major forces elastic tissues surrounding alveoli surface tension Ventilation a When you expand your thorax expand your lungs b Go from neutral to decrease in pressure 3 mmHg Boyle s Law i Inspiration lower intrapulmonary pressure c When expire decrease volume increase pressure 3 mmHg i Higher intrapulmonary pressure 762 mmHg compared to atmospheric pressure of 760 mmHg Resistance to Airflow a Factors i Diameter of bronchi bronchioles 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 IV V VI 1 Bronchoconstriction ACh cold air irritants histamine resting position a Why keep narrow under resting conditions b Smaller cross sectional diameter smaller volume i Anatomical dead space all of the air not involved in gas exchange if must move larger volume of air more work smaller volume more proportionally gets to alveoli 2 Bronchodilation catecholamines E NE sympathetic nervous system a Increase diameter decreases resistance increases flow b Advantage to getting air in more quickly exchange of gases quicker ii Pulmonary compliance 1 Compliant lungs expand easily with expansion of thorax 2 With aging fibrosis more rigid lungs not as compliant a To pull in same volume must work harder for each breath iii Surface tension w in alveoli 1 Each alveolus has tendency to collapse inward a To reduce this effect surfactant breaks reduces surface tension produced by greater alveolar cells type II b If premature baby cannot overcome collective inward force because not making enough surfactant Respiratory Volumes a Tidal Volume 0 5 L b Inspiratory reserve volume at top of tidal volume if you inhale to capacity how much more you can inspire c Expiratory reserve volume how much more can we exhale d Vital capacity inspiratory reserve volume expiratory reserve volume tidal volume e Residual volume amount of air that does not leave lungs after max exhalation 1 5 L i Keeps alveoli from collapsing ii Why can t we get rid of this air Because we have a ribcage this air is not usable Restrictive Pulmonary Disorders a Restrictive disorders reduce pulmonary compliance resulting from fibrosis b Fibrosis resulting from Tuberculosis infection c Result low compliance Obstructive Pulmonary Disorders a Reduces flow obstructs flow b Ex asthma inflammation of airways VII VIII IX c Blue curve normal red curve obstructive disorder takes longer to push air out d FEV forced expiratory volume usually at 1 sec i Inhalation then blow out as hard as you can 90 of vital capacity comes out after 1 sec ii With obstructive disorder flow reduced cannot get out as quickly 1 Affects diameter e Which would result in condition resembling obstructive pulmonary disorder i Pulmonary fibrosis ii Insufficient numbers of great alveolar cells iii Bronchitis decreases diameter increases resistance decreases flow iv Broken ribs Gas exchange a Happens in alveoli b Through diffusion partial pressures i Force exerted on walls of container ii Dalton s law each gas behaves the same way 1 Ex Oxygen is 20 9 of 760 mm Hg 159 mm Hg which is partial pressure c Alveolar air what s in your lungs i Less N2 less O2 more H20 and more CO2 ii Know O2 is roughly 20 in air and 14 in alveolar air 104 mmHg d Henry s Law i Amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in the air ii Partial pressure 1 As increase O2 increase amount of O2 pushed into blood iii Solubility 1 20 O2 vs 20 CO2 more CO2 goes into blood because it is more soluble e External Respiration i We inspire air P O2 104 mmHg in alveolus ii Blood coming into lungs deoxygenated has partial pressure of 40 mmHg iii Less oxygen in blood coming into lungs iv Move O2 from air into blood v P O2 goes from 40 mmHg to 104 mmHg it equilibrates 1 Why not meet in the middle Gas transport a Oxygen i Oxygen carried as oxyhemoglobin and dissolved in blood plasma ii Hb O2 HbO2 Urinary System a Excretion secretion of wastes eliminating something from the body X XI XII i Can defecate marble but do not excrete it b Respiratory excretes CO2 small amounts of other gases and H2O c Integumentary water inorganic salts lactic acid urea in sweat d Digestive system water salts CO2 bile pigments cholesterol metabolic wastes e Urinary many metabolic wastes toxin drugs hormones salts H and water Kidney Function a Filter blood removes waste b Regulate blood volume c Regulate BP d Regulate osmolarity of fluids e Stimulate RBC production f Regulate acid base balance Nitrogenous Wastes a Ammonia is formed from protein catabolism and is toxic b Urea is formed from ammonia in the liver less toxic than ammonia c Uric acid is formed from nucleic acid metabolism d Creatine is formed from breakdown of creatine phosphate Nephron a Tubule and its associated vasculature b The vessels i Glomerulus know of capillaries ii Afferent arteriole going in and efferent arteriole coming out iii Peritubular capillaries vasa recta iv Portal system two capillary beds 1 Afferent glomerulus efferent peritubular capillary c The tubules i Glomerular Bowman s capsule proximal convoluted loop of Henle distal convoluted collecting duct