transport in animals 🛵 Flashcards
why are transport systems needed in multicellular organisms
higher metabolic demand, SA:V ratio insufficient as organism increases in size, transporting molecules made in one region required elsewhere
what makes up a a mass transport system
a pump, a circulatory medium and vessel the carry the medium
what does an open circulatory system consist of
a heart which pumps haemolymph through short vessels and freely into hemocoel, very few vessels
ostium
a small opening or orifice
hemolymph
a circulating fluid in the bodies of some invertebrates that is the equivalent of blood
hemocoel
the system of cavities between the organs of arthropods and molluscs through which the blood circulates
what is carried in haemolymph
food and nitrogenous waste
what is not carried in haemolymph
oxygen and carbon dioxide as gas exchange occurs in tracheal system
what can take place in arthropods and why
diffusion, as fluid comes into direct contact with cells bathing them allowing diffusion to occur before returning the heart
what happened when heart relaxes in arthropods
haemolymph is sucked back in via pores called Ostium
what are the components of a closed circulatory system
blood enclosed in vessels no direct contact to cells, blood pumped by heart under pressure into vessels
how do substances diffuse get to cells
through walls of blood vessels
how is blood flow in vessels adjusted
widening or narrowing of vessels
what is a single circulatory system
one circuit from heart, heart has 2 chambers, passes through 2 sets od capillary’s
what are the 2 types of capillary in single system
gill capillaries, systemic capillaries
why is low pressure need in single system
capillaries would be damaged
why is activity levels of of single system organisms low with the exception of fish why
water supports weight, counter current system
fish circulatory system components
single circuit for blood,2 chambered heart (1 A, 1 V)
what is gill circulation
atrium collects blood from body, ventricle pumps blood to gills for gas exchange, so blood reoxygenated
what is systematic circulation
blood continues through rest of body (from gills) then arrives back at atrium
features of double circulatory system
2 circuits - pulmonary (lungs to heart) and systemic (rest of body and organs)
benefits of double closed circulatory system
keep oxygenated and deoxygenated blood separate (steeper diffusion gradient), have different pressures
components of amphibian circulatory system
3 chambered heart, 2 atria 1 ventricle, double circulatory
what happens to blood in amphibian heart
some mixing of blood in ventricle reducing efficiency of oxygenated
heart of mammals and bird
4 chambers oxgenated and deoxygenated blood seperating impoving effenciency
advantages of single CS
less complex
advantages of double CS
carry blood at different pressures
disadvantages of single CS
low blood pressure, activity of animal tends to be low
disadvantages of double CS
complexity of develpment
elastic fibers role in blood vessels
strech and recoil, made of elastin, provides flexability
smooth muscle role in blood vessels
contract and relax, changes size of lumen
collagen role in blood vessel
structural support, maintains shape and volume
role of narrow lumen in arteries
less space, smaller volume so high pressure
role of thick wall in arteries
outer wall containing collagen, to withstand high pressure, preventing artery from ruptering
role of inner layre (whats its made of?)
muscle and elastic fibers, it maintains pulse flow (contract, relax, streach and recoil) controlling diameter