PHIS 206 1st Edition Lecture 15 Outline of Last Lecture I. Autoregulation of blood flowII. ValvesIII. HypertensionIV. Pulmonary circulationV. Heart failureVI. Circulatory shockOutline of Current Lecture I. Collateral vesselsII. ShockIII. Heart attackIV. InfarctionV. Brain circulationVI. Respiration Current Lecture- Cardiac circulation- Collateral vessels-some small blocks in heart will not have a great effect because there are multiple routes for bloodo Blood can still reach capillarieso Increasing aerobic exercise induces formation of more collateral vessels Prevention of heart attack by exerciseThese 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 Ventricle wall is thicker at the bottom than topo More blood profusion on inner side of wallo Built in mechanism to allow for oxygenation of inner side of wall- Shocko Hypovolemico Can happen because of hemorrhagingo Also from massive tissue bruising Blood flows into intestinal space instead Blood flow outside insteado 10% compensatedo 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 hearto Neurogenic shock Shock that results from parasympathetic output- Example: extreme pain or anxietyo Anesthesia can cause thiso Pain can activate- Heart attacko When blood supply to part of heart is reduced or damaged o Usually result of a clot in muscle or vessel- Infarctiono Event that damages hearto 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-excitableo Fires more action potentials at random, rapid intervalso Heart never fully relaxed or contractedo Cause heart volume to decrease, close to zeroo Danger-after the first few hours of infarction- Handled with defibriliatoro Shocks sent out at 60 cycles per secondo Simultaneously depolarized every cell in hearto Makes every cell simultaneously refractory- Brain circulationo Receives about 15% of cardiac outputo Autoregulation in arterioles of brain, nothing else to modify ito Profusion can’t be maintained if pressure not adequateo 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- Respirationo Primary function: oxygen into the body, carbon dioxide out of the bodyo Lungs-exchange oxygen and carbon dioxideo 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 panto 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% humidifiedo 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
View Full Document