AP Biology Circulatory Systems

AP Biology

Exchange of materials  Animal cells exchange material across their cell membrane  If you are a 1-cell organism that’s easy!  diffusion  If you are many-celled that’s harder

AP Biology Overcoming limitations of diffusion O2O2 CHO aa CH CO 2 NH 3 aa O2O2 CH aa CO 2 NH 3 O2O2 aa CH aa CHO O2O2  Diffusion is not adequate for moving material across more than 1-cell barrier

AP Biology In circulation…  What needs to be transported  nutrients  from digestive system  respiratory gases  O 2 & CO 2 from & to gas exchange systems: lungs, gills  Wastes  from cells  water, salts, nitrogenous wastes (urea)  protective agents  immune defenses  white blood cells & antibodies  blood clotting agents  regulatory molecules  hormones

AP Biology Circulatory systems  All animals have:  fluid = “blood”  tubes = blood vessels  muscular pump = heart openclosed hemolymphblood

AP Biology Open circulatory system  invertebrates  insects, arthropods, mollusks  Blood goes out of vessels

AP Biology Closed circulatory system  invertebrates  earthworms, squid, octopuses  All vertebrates  blood confined to vessels closed system = higher pressures

AP Biology Vertebrate circulatory system  Adaptations in closed system  number of heart chambers differs 4 chamber heart is double pump = separates oxygen-rich & oxygen-poor blood; maintains high pressure What’s the adaptive value of a 4 chamber heart? 234 low pressure to body low O 2 to body high pressure & high O 2 to body and birds

AP Biology Evolution of vertebrate circulatory system fishamphibianreptilesbirds & mammals AA V V VV V AAAA A V 2 chamber3 chamber 4 chamber

AP Biology Evolution of 4-chambered heart convergent evolution Advantages – allows for:  increase body size  protection from predation  bigger body = bigger stomach for herbivores  endothermy  can colonize more habitats  flight  decrease predation & increase prey capture  higher metabolic rate  greater need for energy, fuels, O 2, waste removal  endothermic animals need 10x energy  need to deliver 10x fuel & O 2 to cells

AP Biology Vertebrate cardiovascular system  Chambers  atrium = receive blood  ventricle = pump blood out  Blood vessels  arteries = carry blood away from heart  arterioles  veins = return blood to heart – they have valves  venules  capillaries = thin wall, exchange / diffusion  capillary beds = networks of capillaries

AP Biology Blood vessels arteries arterioles capillaries venules veins artery arteriolesvenules veins

AP Biology Arteries: Built for high pressure pump  Arteries  thicker walls  narrower diameter  elasticity  Largest is the Aorta

AP Biology Veins: Built for low pressure flow  Veins  thinner-walled  wider diameter  blood travels back to heart at low velocity & pressure  blood flows by skeletal muscle contractions squeeze blood through veins  valves  in larger veins one-way valves allow blood to flow only toward heart  Largest vein: Vena Cava Open valve Blood flows toward heart Closed valve

AP Biology valves

AP Biology NR=1&v=O2HEwdnF4o4&featu re=endscreen Valves and muscle pumps

AP Biology Capillaries: Built for exchange  Capillaries  very thin walls  diffusion exchange between blood & cells

AP Biology Controlling blood flow to tissues  controlled by sphincters  Amount of blood depends on need  During exercise – more to legs  During digestion- more to stomach, etc.  capillaries in brain, heart, kidneys & liver usually filled to capacity sphincters opensphincters closed

AP Biology Mammalian heart Coronary arteries to neck & head & arms

AP Biology stroke/animation-how-your- heart-pumps v=Rj_qD0SEGGk Path of blood through the heart

AP Biology Heart beating  K6LkhWs&feature=related K6LkhWs&feature=related

AP Biology AV SL AV Heart valves  4 valves in the heart  flaps of connective tissue  prevent backflow  Atrioventricular (AV) valve  between atrium & ventricle  prevents blood flowing back into atria  “lub”  Semilunar valves  between ventricle & arteries (aorta/pulmonary)  prevent backflow into ventricles “dub” AV valves -Right – tricuspid Left –bicuspid or mitral

AP Biology AV SL AV Lub-dub, lub-dub  Heart sounds  closing of valves  “Lub”  blood against closed AV valves  “Dub”  blood against semilunar valves  Heart murmur  defect in valves causes hissing sound when blood squirts backward through valve

AP Biology Mammalian circulation What do blue vs. red areas represent? pulmonary systemic

AP Biology Pulse  Pulse measures the rate of the heart beat  Average for adults is 70-72X min. but varies with size, exercise, etc.

AP Biology Pacemaker – the S.A. node  Sino-atrial node is the pacemaker – controls the rate of the heart

AP Biology v=IR0nWe47eek Pacemaker

AP Biology Cardiac cycle systolic ________ diastolic pump (peak pressure) _________________ fill (minimum pressure)  contraction phase  systole  ventricles pumps blood out  relaxation phase  diastole  atria refill with blood 110 ____ 70 Average Blood Pressure

AP Biology Measurement of blood pressure  High Blood Pressure (hypertension)  if top number ( systolic pumping) > 150  if bottom number ( diastolic filling) > 90

AP Biology Causes of hypertension  Can be controlled: diet (salt, fat) Habits (smoking) Weight (obesity)  Age, genetics, unknown

AP Biology EKG- measures electrical currents in heart

AP Biology

fibrillation  Irregular contraction of chambers Defibrillator shocks heart Into regular contractions

AP Biology Coronary Arteries  Bring blood (O 2 and glucose) to the heart muscle. (veins bring it back) aorta Left ventricle

AP Biology atherosclerosis Blockage of artery Blockage leads to ANGINA PECTORIS–pain in chest

AP Biology Atherosclerosis  nh7ZesKs nh7ZesKs

AP Biology angioplasty  stents

AP Biology Coronary arteries – heart attack Myocardial infarction -causes damage to heart muscle

AP Biology Coronary artery bypass bypass surgery

AP Biology Bypass

AP Biology Fibrillation  5P8JYg 5P8JYg  pQf_eME pQf_eME

AP Biology Capillaries  H1WxtOw H1WxtOw

AP Biology Lymphatic system  Parallel circulatory system  transports white blood cells  collects interstitial fluid & returns to blood