PHIS 206 1st Edition Lecture 15 Outline of Last Lecture I Autoregulation of blood flow II Valves III Hypertension IV Pulmonary circulation V Heart failure VI Circulatory shock Outline of Current Lecture I Collateral vessels II Shock III Heart attack IV Infarction V Brain circulation VI Respiration Current Lecture Cardiac circulation Collateral vessels some small blocks in heart will not have a great effect because there are multiple routes for blood o Blood can still reach capillaries o Increasing aerobic exercise induces formation of more collateral vessels Prevention of heart attack by exercise 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 o o o Shock o o o Ventricle wall is thicker at the bottom than top More blood profusion on inner side of wall Built in mechanism to allow for oxygenation of inner side of wall Hypovolemic Can happen because of hemorrhaging Also from massive tissue bruising Blood flows into intestinal space instead Blood flow outside instead o 10 compensated o 40 progressive When shock can no longer be compensated When more than 40 of plasma volume is lost Can t maintain pressure to profuse tissues heart o Cardiogenic shock Shock results from something happening in heart o Neurogenic shock Shock that results from parasympathetic output Example extreme pain or anxiety o Anesthesia can cause this o Pain can activate Heart attack o When blood supply to part of heart is reduced or damaged o Usually result of a clot in muscle or vessel Infarction o Event that damages heart o Part of heart that is damaged is infarcted o Outcome Cardiac Tamponnade buffer Every time blood gets pushed up small amount escapes into pericardial sac Amount slowly builds up End diastolic pressure gets smaller then stroke volume gets smaller Systolic stretch When scar becomes big enough it grains elastic properties Stretch in the wall of the ventricle Increasing end systolic volume Fibrillation When heart is damaged it becomes hyper excitable o Fires more action potentials at random rapid intervals o Heart never fully relaxed or contracted o Cause heart volume to decrease close to zero o Danger after the first few hours of infarction Handled with defibriliator o Shocks sent out at 60 cycles per second o Simultaneously depolarized every cell in heart o Makes every cell simultaneously refractory Brain circulation o Receives about 15 of cardiac output o Autoregulation in arterioles of brain nothing else to modify it o Profusion can t be maintained if pressure not adequate o Splanchnic circulation Circulation that involves intestines stomcach pancreas liver All venous draining goes straight to liver Stomach secretes acid neutralized by the secretion of pancreas alkaline They mix in the liver Respiration o Primary function oxygen into the body carbon dioxide out of the body o Lungs exchange oxygen and carbon dioxide o Secondary function Cleans air Humidifies air otherwise dry out mucus in lungs and cause infections Needed for speech Regulate body temperature in animals Humans sweat Animals pant o Ventilation Breathing Movement of air between lungs and the outside Pathway Trachea Branch into 2 bronchi Multiple bronchioles Terminal respiratory bronchioles Alveoli Alveoli Little spheres at the end of terminal bronchioles Conducting zone Volume is about 150mL Conducts air between outside world and respiratory zone Air is at 100 relative humidity Respiratory zone Alveoli an terminal bronchioles Volume about 4500mL Air is now at body temperature Air is now 100 humidified o If air was brought in cold it would dry out the membranes of epithelial cells Causes cracks and infections Mucocilliary system Cleans air Traps dirt particles Pushes then to the back of the throat then swallowed