Discussion: (13 marks)
1. Which ventricle has a thicker muscular wall?
Explain the importance of the thicker wall to its function.
(3
marks)
Left ventricle has a thicker muscular wall (1).
Left ventricle needs to produce a higher blood
pressure (1) which pump blood to all parts of the body
(except lungs) / more distant parts of the body
(1).
2. Compare
the thickness of the wall between atria and ventricles. Explain the significance
for this difference. (3 marks)
The walls of atria are thinner (1).
It is because atria only need to pump blood to the
ventricles which are closed to the atria (1).
There is no need for atria to have thick muscle to
create a large pumping force (1).
3. Make a
label for the location of the valves in your drawing. Explain the use of the
valves.
(2 marks)
As shown in the drawing (1);
The valves prevent the backflow of blood (1).
4. Where
are valves found apart from the position between atria and ventricles? What is
their function? (2 marks)
They are found at the openings of the arteries (1).
They prevents backflow of blood from the arteries
to the ventricles (1).
5. Identify
the coronary blood vessels on the surface of the heart. State their functions
and explain the outcome if the vessels are blocked. (3 marks)
Coronary arteries supply oxygen and nutrients to
the cardiac muscles (1).
If these blood vessels are blocked, the cardiac
muscles no longer receive oxygen and become die (1).
The heart cannot beat normally any more/ Coronary
heart disease or heart attack is caused (1).
沒有留言:
張貼留言