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29 Cards in this Set
- Front
- Back
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How many chambers does the fish heart have?
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4
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Name the chambers of a fish heart
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Sinus venosus
Atrium Ventricle Bulbus arteriosus or conus arteriosus (contains valves) |
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What is the conus/bulbus arteriosus an extension of?
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Conus - ventricle
Bulbus - aorta |
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Why is the dorsal aorta in fish stiff and not elastic?
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If it were elastic blood would flow rapidly through the gills during each heartbeat
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How many chambers do amphibians have in their hearts?
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3
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What are the chambers of the amphibian heart?
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right and left atrium
ventricle |
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What is the spiral valve?
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Found in conus arteriosus, blocks and unblocks entrances to pulmonary artery to lungs and pulmonary artery to skin
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Where does blood coming from the lungs and skin go to?
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Lungs - oxygenated - left atrium
Skin - partially oxygenated - right atrium |
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Describe the amphibian lymphatic system
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Lymph hearts
Beat independently of heart Brings lymph back to heart |
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How many chambers does a reptilian heart have?
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3
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What is the ventricle in reptiles divided into?
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Cavum venosum - right atrium
Cavum arteriosum - left atrium Cavum pulmonale - opens into pulmonary artery |
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How do reptiles cope with oxygen starvation?
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Muscular ridge and AV valve cause blood not to go to lungs but to aortic arches and systemic circulation
e.g. turtle diving, snake eating prey |
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How do reptiles blood shunt?
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Controlled by differences in pressure between pulmonary and systemic circulation
Vasoconstriction in pulmonary circulation means that blood is shunted away from lungs to systemic circulation |
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What are the advantages of shunting?
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Thermoregulation
Breath-holding while diving Stabilise oxygen levels during intermittent breathing |
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How can shunting be a problem during anaesthesia?
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Chronic pneumonia/lung damage may increase lung resistance - shunting of blood away from lungs
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What is the reptilian renal portal system?
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Ensures that when there is reduced blood flow to glomerulus, there is still adequate perfusion to renal tubules
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Which reptile has a 4 chambered heart?
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Crocodile
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What connects the base of the right and left systemic trunks in the crocodile?
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Foramen of Panizza
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What are dog teeth?
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Found in Foramen of Panizza, controlled by adrenaline.
Absence of adrenaline, cog teeth shut, blood diverted away from lungs to systemic circulation |
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Do reptiles have lymph hearts?
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yes
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How many chambers do birds have in their hearts?
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4
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What are 3 differences between the avian and mammalian heart?
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Ascending aorta curves to right
Right AV valve has no chorda tendinae, thick muscular flap of myocardium Left AV valve is tricuspid |
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How do the sizes of bird hearts differ from mammalian hearts?
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Usually bigger with larger cardiac output
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turkeys
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high blood pressure
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How do active birds increase cardiac output?
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Increase heart rate
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How do diving birds adapt?
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Vasoconstriction, bradycardia, drop cardiac output
Blood diverted to brain to prevent hypoxia |
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What do birds and reptiles excrete instead or urea?
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Urates - uric acid
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Where in birds does blood from the pelvic limbs go?
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Rest - through kidneys into caudal vena cava
Stress - adrenaline closes portal valves, blood bypasses kidneys |
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Why are birds quite tolerant to blood loss?
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Vasoconstriction in skeletal muscle - causes
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