Topic 1
, Why do we need a
circulatory system ?
(mass transport)
QUESTION
To transport the essential substances
around
the body .
Larger organisms require a circulatory
system to overcome the limitations of
diffusion .
ANSWER
, Why does diffusion become
inefficient for larger organisms ?
C3 points)
QUESTION
SA : V
i
&
metabolic y
As the organism becomes larger :
↳ surface area to volume ratio decreases -
>
-
Diffusion distance increases
- Metabolic rate increases
ANSWER
, What are the features of a mass
transport system ?
14 points)
QUESTION
#
1 .
Network to more through
↳ veins ,
arteries , capillaries
2
. A medium for movement (a fluid ,
eg .
blood) 0 O 0
.
3 controlled directions >
S
↳ vessels have values =
preventing backflow
↳ moved along a pressure gradient
4
. Maintain of speed E
& elastic recoil of vessels
)
↳ contraction of heart
help maintain pressure gradient-speed
ANSWER
, What does it mean by single and
double circulatory system ?
QUESTION
i gle circulatory system
#
↳ The blood flows through the heart only once
completing a full circuit in the body
(eg . Fish
⑳be circulatory system
*
↳ The blood flows through the heart
nice in one
complete circuit
ANSWER
, What are the coronary arteries ?
QUESTION
They are arteries wrapped around the heart
and supply blood to the cardiac muscles
BLOOD- HEART
coronary
arteries
ANSWER