Regents Biology Circulatory System Blood

Regents Biology Blood & blood cells  Blood is a tissue of fluid & cells  plasma (55% of volume)  fluid  dissolved salts, sugars, proteins, and more  cells (45% of volume)  red blood cells (RBC)  transport O 2 in hemoglobin  white blood cells (WBC)  defense & immunity  platelets  blood clotting

Regents Biology Blood Cell production ribs, vertebrae, breastbone & pelvis  Stem cells  “parent” cells in bone marrow  differentiate into many different types of cells white blood cells red blood cells white blood cells

Regents Biology Red blood cells  Small round cells  produced in bone marrow  lose nuclei & mitochondria  more space for hemoglobin  iron-containing protein that transports O 2  last 3-4 months (120 days)  filtered out by liver  ~3 million RBC destroyed each second

Regents Biology Hemoglobin  Protein which carries O 2 O2O2 O2O2 O2O2

Regents Biology Red blood cell production  5-6 million RBC in tiny drop of human blood  5 liters of blood in body = 25 trillion RBC  produce ~3 million RBC every second in bone marrow to replace cells lost  each RBC 250,000 molecules hemoglobin  each Hb molecule carries 4 O 2  each RBC carries 1 million O 2

Regents Biology Blood clotting fibrin protein fibers build clot emergency repair of circulatory system platelets seal the hole chemical emergency signals

Regents Biology Circulatory System in Animals

Regents Biology  Supplies in  fuel (sugars)  digestive system  oxygen  respiratory system  Waste out  CO 2  respiratory system  Need to pick up & deliver the supplies & wastes around the body  circulatory system Feeding the Need for Energy

Regents Biology Circulatory system  Made up of 3 parts  organ  heart  tissues & cells  blood  red blood cells  blood vessels (vascular system)  arteries  veins  capillaries

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

Regents Biology Vertebrate Heart  4-Chambered heart  atria (atrium)  thin wall  collection chamber  receive blood  ventricles  thick wall pump  pump blood out right atrium left atrium right ventricle left ventricle

Regents Biology Evolution of circulatory system fishamphibianreptilesbirds & mammals AA V V VV V AAAA A V 2 chamber3 chamber 4 chamber Birds AND mammals! Wassssup?! Not everyone has a 4-chambered heart

Regents Biology Evolution of circulatory systems convergent evolution  What advantage was a 4-chambered heart  increase body size  fuel warm-blooded  enable flight  Higher energy needs  greater need for energy, fuel, O 2, waste removal  warm-blooded animals & flying need 10x energy  need to deliver 10x fuel & O 2

Regents Biology AV SL AV Heart valves  4 valves in the heart  flaps of connective tissue  prevent backflow  Atrioventricular (AV) valve  between atrium & ventricle  keeps blood from flowing back into atria when ventricles pump  “lub”  Semilunar valves  between ventricle & arteries  prevent backflow from arteries into ventricles  “dub”

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

Regents Biology Cardiac cycle  1 complete sequence of pumping  heart contracts & pumps  heart relaxes & chambers fill  contraction phase  systole  ventricles pumps blood out  relaxation phase  diastole  atria refill with blood

Regents Biology Electrical signals allows atria to empty completely before ventricles contract stimulates ventricles to contract from bottom to top, driving blood into arteries  heart pumping controlled by electrical impulses  signal also transmitted to skin = EKG

Regents Biology pump (peak pressure) _________________ fill (minimum pressure) Cardiac Cycle How is this reflected in blood pressure measurements? chambers fill ventricles fill ventricles pump systolic ________ diastolic 110 ________ 80

Regents Biology Measurement of blood pressure hypertension = (high blood pressure) if systolic > 150 or if diastolic > 90

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Regents Biology Circulatory System Blood Vessels

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

Regents Biology Arteries: Built for their job  Arteries  blood flows away from heart  thicker walls  provide strength for high pressure pumping of blood  elastic & stretchable  maintains blood pressure even when heart relaxes

Regents Biology Major arteries pulmonary artery pulmonary artery = to lungs aorta carotid = to head to brain & left arm to right arm coronary arteries to body

Regents Biology Veins: Built for their job  Veins  blood returns back to heart  thinner-walled  blood travels back to heart at low speed & pressure  why low pressure?  far from heart  blood flows because muscles contract when we move  squeeze blood through veins  valves in large veins  in larger veins one-way valves allow blood to flow only toward heart Open valve Blood flows toward heart Closed valve

Regents Biology Major Veins pulmonary vein = from lung superior vena cava = from upper body pulmonary vein = from lung inferior vena cava = from lower body

Regents Biology Structure-function relationship  Capillaries  very thin walls  allows exchange of materials across capillary

Regents Biology Controlling blood flow to tissues  Capillary function  exchange between blood & tissues  O 2, CO 2, H 2 O, food, waste  blood flow in capillaries controlled by pre-capillary sphincter valves pre-capillary sphincters openpre-capillary sphincters closed

Regents Biology Capillary Beds  Blood flow  at any given time, only 5-10% of body’s capillaries have blood flowing through them  supply varies as blood is needed  after a meal, blood supply to digestive tract increases  during strenuous exercise, blood is diverted from digestive tract to skeletal muscles  capillaries in brain, heart, kidneys & liver usually filled to capacity Why?

Regents Biology Circulation of Blood  2 part system  Circulation to lungs  blood gets O 2 from lungs  brings O 2 -rich blood back to heart  Circulation to body  pumps O 2 -rich blood to body  picks up nutrients from digestive system  brings CO 2 & cell wastes from body to heart heart lungs body Circulation to lungs Circulation to body

Regents Biology Vertebrate circulatory system heart lungs body  2 part system artery to body artery to lungs vein from lungs to heart vein from body to heart

Regents Biology Stops along the way…  Lungs  pick up O 2 / clean out CO 2  Small Intestines  pick up nutrients from digested food  Large Intestines  pick up water from digested food  Liver  clean out worn out blood cells

Regents Biology More stops along the way…  Kidneys  filters out wastes (urea)  excess salts, sugars & water  Bone  picks up new red blood cells  Spleen  picks up new white blood cells

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Regents Biology Cardiovascular disease  Atherosclerosis & Arteriosclerosis  deposits inside arteries (plaques)  develop in inner wall of the arteries, narrowing their channel  increase blood pressure  increase risk of heart attack, stroke, kidney damage normal arteryhardening of arteries

Regents Biology Cardiovascular health  Genetic effects  Diet  diet rich in animal fat increases risk of CV disease  Exercise & lifestyle  smoking & lack of exercise increases risk of CV disease bypass surgery

Regents Biology Cardiovascular health (U.S. 2001) Heart Disease 696,947 Cancer 557,271 Stroke 162,672 Chronic lower respiratory diseases 124,816 Accidents (unintentional injuries) 106,742 Diabetes 73,249 Influenza/Pneumonia 65,681 Alzheimer's disease 58,866 Nephritis, nephrotic syndrome & nephrosis 40,974 Septicemia 33,865

Regents Biology Heart Disease Heart disease death rates Adults ages 35 and older

Regents Biology Women & Heart Disease  Heart disease is 3rd leading cause of death among women aged 25–44 years & 2nd leading cause of death among women aged 45–64 years. Risk factors  Smoking  Lack of exercise  High fat diet  Overweight Death rates for heart disease per 100,000 women, 2002

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Regents Biology Lymphatic system  Parallel circulatory system  transports WBC  defending against infection  collects interstitial fluid & returns to blood  maintains volume & protein concentration of blood  drains into circulatory system near junction of vena cava & right atrium  transports fats from digestive system to circulatory system

Regents Biology Lymph System

Regents Biology Thermoregulation Vasoconstriction Vasodilation  Vasodilation & vasoconstriction  adjusts blood flow  evaporative cooling

Regents Biology Counter Current Exchange Cold blood Warm blood Capillary bed Veins 5˚C temperature of environment 36˚C core body temperature Artery blood from arteries warms blood in veins

Regents Biology Coronary arteries bypass surgery

Regents Biology Simpler organisms When your body is only 2-cell layers thick, you can get supplies in and waste out just through diffusion  all cells within easy reach of fluid Hydra Jellyfish