unit 9 Flashcards
function of circulatory system
rapidly transport substances throughout the body
arteries vs veins
arteries carry blood away from the heart. veins carry blood towards the heart.
artieries branch into network of arterioles and then to capillaries where exchange takes place
vasoconstriction
contraction of smooth muscle in the walls of blood vessel. decreased the blood flow through vessels
vasodilation
relaxation of smooth muscle which increases blood flow through the vessels
how is blood distribution regulated in the body
vasoconstriction and vasodilation
what controls blood flow into into capillary beds
precapillary sphincters
fish main gas exchange
gills
single circulation
common in fish.
blood passes only once through the heart in a circuit.
all blood leaving the heart is pumped to the gills. blood is oxygenated in the capillaries of secondary lamellae, this is branchial circulation.
after leaving gills oxygenated blood flows to other tissues of the body. blood through through all of body but gas exchange surfaces is systemic circulation.
tetrapod blood circuit
double circulation. blood leaves right side of the heart and is pumped to the lungs. blood is oxygenated from capillaries (pulmonary circulation). from left side blood is pumped to all other parts of body.
portal systems
cases where deoxygenated blood leaces a capillary bed and passes through a second capillary bed before returning to the heart
hepatic portal system
blood is delivered directly from the lining of the digestive system to the liver
branchial circulation
supplies the gills with blood.
blood is pumped from the heart into the ventral aorta, then into the aortic arches. in each aortic arch the afferent branchial artery delivers blood to the capillaries of the gills while the efferent branchial artery carries blood awat from the gills to the dorsal aorta
in myxinoidea and petromyzontida what supplies the gills with blood
all of the aortic arches
in chondrichthyes what supplies the gills with blood
aortic arches 2-7. oxygenated blood is supplied to the spiracle by a branch of the efferent portion of the aortic arch 2
in actinopterygii what supplies the gills with blood
aortic arches 3,4,5,6
anurans aortic arches 3,4,6
3 forms the carotid artery (supplies blood to head)
4 becomes the aortic arch
6 forms the pulmocutaneous arch which supplies blood to the lungs and skin
sauropsid and mammal aortic arch 3,4,6
3 forms teh carotid artery which supplies blood to head
4 becomes the aortic arch
6 forms the pumocutaneous arhc which supplies blood to lungs and skin
lepidosauria, testudinata, crocdillia aortic arch 4
forms both a right and left aorta.
what separates chambers of the heart
one way valves
myogenic heart
cardiac muscle cells can stimulate themselves to contract
sinus venosus is the fastest so it sets the rhythm
chondrichthyes, sarcopterygii, amphibians chamber after ventricle
conus arteriosus.
contractile heart chamber composed of cardiac muscle
once the ventricle has contracted adn begins to relax then the conus arteriosus contracts which prolongs the period of blood flow
petromyzontida and actinopterygii chamber after ventricle
bulbus ateriosus.
heart chamber composed of smooth muscle as well as collage and elastic fibres.
when the ventricle contracts the bulbus arteriosus stretches then slowly recoils gently squeezing blood into the ventral aorta.
this prolongs the period of blood flow and minimizes the pressure generated by the ventricle
how many hearts does myxinoidea have
main one is branchial which consists of sinus venosus, atrium, and ventricle. pumps blood through the ventral aorta to the gills.
portal heart has one chamber. pumps blood through the hepatic portal vein into the liver.
petromyzontida heart parts
sinus venosus, atrium, ventricle, bulbus arteriosus
chondrichthyes heart parts
sinus venosus, atrium, ventricle, conus arteriosus
actinopterygii heart parts
sinus venosus, atrium, ventricle, and bulbus arteriosus
adult amphibians atrium
completely divided into right atrium and left atrium. deoxygenated blood returning from the systemic circulation enters the sinus venosus then the right atrium. oxygenated blood returning from the lungs enters the left atrium.
lepidosauria and testudinata hearts
small sinus venosus that pumps blood into the right atrium. sinus venosus is the pacemaker
archiosauria, crocodillians, birds ventricle
completely divided. no mixing of oxygenated and deoxygenated blood.
crocodillia controlling blood
crocdiles can control where they send their blood. right ventricle to the lung is normal, or systemic circulation (right to left cardiac shunt)
foramen of panizza
crocodillia. in normal state the blod flows from the left ventricle through the foramen of panizza to the left aorta
aves pace maker
tiny sinus venosus
mammals sinus venosus
reduced to small patch of tissue in the wall of the right atrium. sinoatrial node acts as the pacemaker of the heart.
do mammals or sauropsids have a conus arteriosus as adults
no
do birds of mammals mix oxygenated or deoxygenated blood
no
does the right or left ventricle need to generate more force?
the left needs more force since it does systemic circulation whereas the right just does pulmonary
pulmonary edema
blood pressure is too high in pulmonary arteries and fluid is forced out of the capillaries into the alveoli or capillaries.
diving mammals have this to help maintain constant blood flow while diving
aortic bulb. it is elastic, non pumping enlargement of the aorta (systemic arch).
