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Animal Circulation and Animal Circulation and Gas ExchangeGas Exchange
Cardiovascular Cardiovascular SystemSystem
• Heart– atria &
ventricles
• Arteries• Arterioles• Capillaries• Venules• Veins
Evolution of the Vertebrate HeartEvolution of the Vertebrate Heart• Two chambers (one atria and one ventricle)
– along with a sinus venosus and a conus venosus)
• Two chambers plus septa– lungfish
Evolution of the Vertebrate HeartEvolution of the Vertebrate Heart• Three chambers (two atria and one ventricle)
– amphibians, reptiles
Evolution of the Vertebrate Evolution of the Vertebrate HeartHeart
• Four chambers (two atria and two ventricles)– Crocodilians,
mammals, birds
Path of Blood Through Path of Blood Through The HeartThe Heart
• Anterior and Posterior Vena Cava
• Right Atria• Atrioventricular (AV)
Valve (tricuspid)• Right Ventricle• Semilunar Valve• Pulmonary Arteries• Lungs
• Pulmonary Veins• Left Atria• Atrioventricular (AV)
Valve (bicuspid)• Left Ventricle• Semilunar Valve• Aorta• Body
Cardiac CycleCardiac Cycle
Diastole Atrial Systole
Ventricularr Systole
Contract Neither
Atria Ventricle
Valves AV open Semilunar closed
AV open Semilunar closed
AV closed Semilunar open
Time 0.4 sec 0.1 sec 0.3 sec
Function Fill Heart Overfill Ventricle
Pump Blood
Cardiac OutputCardiac Output• Volume of blood per minute from the left
ventricle• Depends on two factors
– Heart rate (pulse)– Stroke volume
• Average Human– 75 ml/beat– 70 beats/min– 5.25 L/min (your blood volume)
Control of Heart RhythmControl of Heart Rhythm• Sinoatrial node (pacemaker)• Atrioventricular node
Mammalian Blood CompositionMammalian Blood Composition
• Cellular Elements (45%)– Erythrocytes– Leukocytes– Platelets
• Plasma (55%)– Water– Ions– Plasma Proteins– Nutrients– Wastes– Gases– Hormones
Blood ClottingBlood Clotting
• Injury triggers platelets to area• Changes prothrombin to thrombin which than
converts fibrinogen to fibrin
Blood PressureBlood Pressure
• Systolic Pressure• Diastolic Pressure
Cardiovascular DiseaseCardiovascular Disease
• Hypertension• Heart Attack• Stroke• Atherosclerosis• Arteriosclerosis• LDL’s• HDL’s
Cardiovascular “Surgeries”Cardiovascular “Surgeries”
• Angiogram• Angioplasty• Stents
Cardiovascular “Surgeries”Cardiovascular “Surgeries”
• Bypass Surgery
Cardiovascular DiseaseCardiovascular Disease
Cardiovascular DiseaseCardiovascular Disease
Cardiovascular DiseaseCardiovascular Disease
• Hypertension• Heart Attack• Stroke• Atherosclerosis• Arteriosclerosis• LDL’s• HDL’s
Gas Gas ExchangeExchange
Conditions for Respiratory Conditions for Respiratory SurfacesSurfaces
• Large surface area
• Thin
• Moist
Aquatic vs. TerrestrialAquatic vs. Terrestrial
• Less than 1% oxygen• Oxygen amounts
decrease as the temperature increases
• Aquatic animals use large amounts of energy to obtain oxygen (20%)
• About 21% oxygen• Developed
invaginations to increase surface area and decrease evaporation
• Terrestrial animals may use only 1% - 2% of its energy to obtain oxygen
Respiratory SurfacesRespiratory Surfaces
• Cutaneous Respiration
• Gills
• Tracheal Systems
• Lungs
Cutaneous RespirationCutaneous Respiration
• Direct diffusion of gases between the organism and the environment
• Found in Porifera, Cnidarians, Platyhelminthes, nematodes, and some annelids
• Supplements other organisms
GillsGills
• Found in echino-derms, mollusks, annelids, arthropods, some vertebrates
• Countercurrent Gas Exchange
Countercurrent Gas ExchangeCountercurrent Gas Exchange
• Maintains gradient over the whole length of the capillaries
• Extracts 80% of the oxygen from the water
Tracheal SystemsTracheal Systems• Found in arthropods• Tracheae
– open tubes
• Spiracles– openings
• Tracheoles– contact with cells
• Muscle– increase amount of Carbon
Dioxide removed
Tracheal SystemsTracheal Systems
Diffusion LungsDiffusion Lungs
• Found in invertebrates
• Gas moved primarily by diffusion– may be increased by body movement
• Modifications– snails - cavity with gill modified into lung– scorpions and spiders - invaginations of the
abdomen
Ventilation Ventilation LungsLungs
• Found in amphibians, reptiles, mammals and birds
• Pharynx• Larynx• Trachea• Bronchi• Bronchioles• Alveoli
AlveoliAlveoli
Ventilating The LungsVentilating The Lungs
• Positive Pressure Breathing– pushes air down
trachea– seen in frogs and
other amphibians
• Negative Pressure Breathing– suction created by
diaphragm– seen in mammals
Negative Pressure BreathingNegative Pressure Breathing
Avian RespirationAvian Respiration• Airs sacs allow for one-way ventilation• Parabronchi rather than alveoli
Breathing Breathing ControlControl
• Occurs in Medulla oblongota and Pons
• Monitors Carbon Dioxide (converts to carbonic acid)– lowers pH and
causes increase in depth and rate of breathing
Carbon Dioxide TransportCarbon Dioxide Transport
• Carbon dioxide transported from tissue by erythrocyte– 7% transported as Carbon Dioxide in blood– 23% of Carbon Dioxide and most of the
Hydrogen ions are attached to hemoglobin – 70% transported as Bicarbonate in plasma
Deep-diving MammalsDeep-diving Mammals• Stores large amounts of
oxygen in blood and muscles (twice as much as us)– twice the volume of blood– huge spleen– myoglobin
Deep-diving MammalsDeep-diving Mammals• Conservation techniques
– exhale before diving (prevent bends / pressure)
– decrease heartrate and oxygen consumption
– reduce blood supply to muscles (anaerobic)
SmokingSmoking
• In the United States, an estimated 26.2 million men (23.5 percent) and 20.9 million women (18.1 percent) are smokers. These people are at higher risk of heart attack and stroke.
• Every eight seconds, someone dies from tobacco use.
• Cigarettes cause more than one in five American deaths.