Adaptations for transport: Animals Flashcards
does insects have an open or closed circulatory system?
open
explain and describe an insect’s circulatory system
fluid is pumped at relatively low pressure from one main long, dorsal tube-shaped heart running the length of the body
fluid called haemolymph bathes the tissue directly, enabling the exchange of substances
when the heart relaxes the haemolymph is sucked slowly back to the heart
there is no respiratory pigment in the insect haemolymph as oxygen diffuses directly to respiring cells through the tracheal system
what does dorsal mean?
at the top/front
what is the blood cavity in the insect called?
haemocoel
what are two examples of organisms with a closed circulatory system?
mammals
fish
explain and describe a mammal/fish’s circulatory system
blood circulates in a fully enclosed system of tubes (blood vessels)
the heart is a muscular pump, pushing blood at high pressure and with a rapid flow rate
organs are not in direct contact with the blood but are bathed in tissue fluid
blood carrier a respiratory pigment which carries oxygen
explain and describe an earthworm’s circulatory system which is closed
has dorsal and ventral vessels running through the length of the body
these are connected by five pairs of pseudohearts
blood contains a respiratory pigment which carries oxygen
what is the difference of blood pressure in a closed vs open circulatory system?
open -
blood under low pressure as it’s not contained within vessels
closed -
blood under high pressure as it is contained within vessels
what is the difference between fluid being in direct contact with organs in an open vs closed circulatory system?
open -
as haemolymph leaves the circulatory system it bathes the organs directly
closed -
as blood is contained within blood vessels, blood never has direct contact with organs
where is blood contained in in open vs closed systems?
open -
blood is pumped from a long dorsal tubular heart into spaces within the body cavity
closed -
blood is always within vessels which include arteries, veins and capillaries
is a respiratory pigment needed in a closed and open system?
open -
oxygen reaches the gas exchange surface via a tracheal system so no respiratory pigment needed to carry oxygen around the body
closed -
oxygen diffuses into the blood and is carried around the body in blood bound to haemoglobin which is the respiratory pigment
where is oxygen transported in a closed and open system?
open -
oxygen is transported directly to tissues
closed -
oxygen is transported from the exchange surface/lungs to the heart and then towards capillaries in body tissues
what is single circulation and which organism has this?
blood passes through the heart once in one complete circulation eg fish
what is double circulation and which organism has this?
blood passes through the heart twice in one complete circulation eg mammals
what are the two circuits in double circulation?
pulmonary circulation
systemic circulation
what is the pulmonary circulation?
to do with lungs
all of the blood vessels involved in transporting blood between the heart and the lungs
what is systemic circulation?
to do with respiring tissues
all of the blood vessels involved in transporting blood between the heart and respiring tissues
how many chambers does a fish heart have?
2
how many chambers does a mammal heart have?
4
give three advantages of a double circulation system over a single circulation system
maintains a high blood pressure in the systemic circulation
allows a lower pressure in the pulmonary circulation
rapid circulation in the systemic circuit
explain the advantage of maintaining a high blood pressure in the systemic circulation
high blood pressure ensures blood reaches all tissues even those very far from the heart
explain the advantage of allowing a lower pressure in the pulmonary circulation
low pressure prevents tissue fluid being pushed out of capillaries into the lungs
explain the advantage of paid circulation in the systemic circuit
ensures oxygen is delivered to respiring cells rapidly
why is it important that oxygenated and deoxygenated blood is kept separate?
maintains a steep concentration gradient for oxygen at the lungs and at respiring tissues
what are the 3 major blood vessels that make up the mammalian circulatory system?
arteries
veins
capillaries
what is the role of arteries?
carries deoxygenated blood away from the heart at high pressure
what is the role of veins?
transports blood to the heart at low pressure
what is the role of capillaries?
smallest vessels that allows exchange of substances with body cells and takes blood as close as possible to all cells
what is the size of an artery?
1-10 mm
what is the size of a vein?
1-15mm
what is the size of a capillary?
<1
describe the endothelium present in the 3 major blood vessels
it is the innermost layer of the vessel, is one cell thick and provides a smooth lining
why is it important that the endothelium is smooth?
to minimise friction to reduce resistance to blood flow
what is the tunica media made of in the arteries?
elastic fibres and smooth muscle
out of veins and arteries, which has the thicker tunica media?
arteries