chapter 42 Flashcards
why is exchange easy for unicellular organisms?
there’s direct contact with the environment
what are the two basic adaptations for effective exchange in animal cells?
- be small or thin, places cell in direct contact
2. use of a circulatory system for larger organisms
what do animals do if they don’t have a a circulatory system?
they have a gastrovascular cavity that does digestion and gas exchange, only 2 cells thick
what are the three basic components for a circulatory system?
fluid-transport gases through body
vessel- where fluid flows through
muscular pump- power circulation
what is an open circulatory system?
dont have artery or veins, organs in “blood bath”, carries di/oxygenated blood in/out. in anthropods snails, clams, oysters
what is the open circulatory fluid called?
hemolymph or interstitial fluid
what is a closed circulatory system?
directly pumping blood from heart to organs, di/oxygenated blood not mixed, in worms and vertbrates
what is the closed circulatory fluid called?
blood
what is the advtange of open circulatory systems?
lower hydrostatic pressure= less energy
what is the advantage of a closed circulatory system?
high blood pressure= efficient delivery of oxygen and nutrients
what is the closed circulaory system of humans and other vertbrates?
cardiovascular system
what are arteries?
always carrying blood away from heart to organs
what are arterioles?
branched arteries
what are beds?
gas exchange between blood and interstitual fluid
what are veins?
deoxygenated blood back to heart
what are venules?
picking up CO2 and going back to heart
w=how are arteries and vein distinguished?
direction of blood flow
?what do portal vessels do
carry blood between beds of capillaries
what is the artrium?
receives blood
what is the ventricle?
pumps blood out of heart
why is the ventricular muscle bigger?
it needs to pump blood out
in bony fishes, rays, and sharks, the heart consists of 2 chambers ____ and ____
atrium and ventricle
what is single circulation?
the blood passes through the heart once in each complete circuit through the body
how does swimming make up for low blood pressure in single circulation?
swimming contracts and relaxes the muscles and help accelerate the slow rate of circulation
the circulatory systems of amphibians, reptiles, and mammals have 2 circuits called?
double circulation
what is a pulmonary circuit?
if capillary beds involved are all in the lungs (reptiles and mammals)
what is pulmocutaneous circuit?
if it includes capillaries in both lungs and skin (amphibians)
what is a systemic circuit?
when oxygenated blood leaves the gas exchange tissues it goes to the left side of the heart to be pumped into organs. once its used the now dioxygenated blood will return to the heart
what are intermittent breathers?
vertebrates that can go long periods without gas exchange bc they can breathe through their skin. shuts off blood flow to the lungs.
what do the left and right sides of the 4 chambered heart do?
left-oxygenated
right-dioxygenated
why do mammals and birds require more oxygen than ectotherms?
they need more energy
describe the pathway of a 4 chamber heart
- dioxygenated blood comes through right atrium
- goes to right ventricle pumps into pulmonary vein
- goes to pick up oxygen in lungs
- goes back to pulmonary veins
- enters left atrium (collecting chamber)
- left ventricle (pumping chamber)
- leaves through aorta
- back down into body
why do the atria have thin walls?
they are just collection chambers for returning blood, blood is relaxed
why do the ventricles have thicker walls?
because they have to pump blood