EXAM QUESTIONS – Circulation
Blood Vessels
1 (b) During physical activity, oxygen is supplied to the muscles through the blood system.
Describe two characteristics of veins which assist the transport of blood. (2 marks)
Blood Pressure
Blood Vessels
Control of Heart Rate, Training
Oxygen transport at the tissues
Blood Pressure
Cardiac Dynamics
Control of Heart Rate
Venous Return
Cardiac Dynamics , Training
Training and Control of Heart Rate
Blood Shunting and Venous Return
Blood Pressure
Jun 04 - Qu 5
When playing golf, a player’s blood velocity and pressure is similar to the graph below.
(a)
(i)
Using the graph identify blood vessels represented by A, B, C, D and E.
(3 marks)
(ii)
Explain the variation in blood pressure and blood velocity occurring from A to
E.
(3 marks)
Jan 2002 - Qu 3
(c)
In a variation of baseball, the batter has to run every time he strikes the ball. At the
end of an extended innings, the information in Table 2 was obtained.
Table 2 - Estimated blood flow in cm3 per minute
Organ system
Skeletal muscle
Heart
Skin
Kidneys
Abdominal
organs
Brain
Other
Total
Prior to
batting
1200
250
500
1100
1400
750
600
5800
%
21.0
4.0
8.5
19.0
24.0
After extended
innings
12500
750
1900
600
600
%
72.0
4.0
11.0
3.5
3.5
13.0
10.5
100
750
400
17500
4.0
2.0
100
Using information from table 2 account for the changes in the blood flow during
exercise to:
(i)
the skin;
(ii)
the heart.
(3 marks)
June 05 - Qu 4
The information in table 3 was obtained from a performer at rest and during a game of
hockey.
(c)
(i)
Explain why the blood flow to the brain remains the same at rest and during
the game.
(2 marks)
(ii)
Explain why there is a need for blood flow to increase to the skeletal muscles
during the game and how this is achieved.
(4 marks)
MARK SCHEME – Circulation
1 (b) Describe two characteristics of veins which assist the transport of blood.
(2 marks) Veins:
A. Thinner muscle/elastic
tissue layer
B. Valves
C. Wider lumen/diameter
D. Blood at low pressure
June 04 - Qu 5
(a) (i)
A – Arteries, B – Arterioles, C – Capillaries, D – Venules, E – Veins;
3 marks for 5 correct, 2 marks for 4 correct, 1 mark for 3 correct
(ii)
1. Velocity related to cross sectional area;
2. Smaller the area, faster the flow;
3. Capillaries – largest total cross sectional area – slow blood flow;
4. Veins/venules – smaller cross sectional area – faster flow;
5. Assisted by venous return mechanisms;
6. Pressure relates to resistance to flow;
7. Friction between blood and walls of vessels;
8. Friction depends on smoothness of lining and diameter of vessel/viscosity of blood;
9. Localised arterial constriction;
max 3
Jan 2002 - Qu 3
(c) 1 Skin-more blood to surface( capillaries);
2 To lose heat by radiation/evaporation/conduction/convection;
3 (Heart - increased heart rate) hence more oxygen and nutrients to heart required.
(3 marks)
Jan 04 - Qu 1
(a)
1 Brain function needs to be maintained during exercise/or at rest;
2 Brain requires glucose/feeding/oxygen(O2).
2 marks
(b)
1 Digestion and absorption of food takes time;
2 During exercise, there is reduced blood flow to the gut;
(accept references to figures)
3 If the gut is full, blood will be diverted to the stomach;
4 Denying blood to the active muscles;
5 Affecting performance/lack of oxygen (O2 )to muscles/equiv;
(do not accept stitch or cramp)
6 Feeling nauseous/sick.
3 marks
(c)
1
2
3
4
5
6
Active muscles require nutrients/oxygen (O2);
Blood is redirected/shunted to (active) muscles;
This is achieved by the action of the autonomic/sympathetic system;
Vasodilatation/allowing greater flow to areas needing blood;
Vasoconstriction/restricting blood flow;
Pre-capillary sphincters/control blood flow into the capillary flow.
4 marks
June 05 - Qu 4
(c) (i) 1. Brain function needs to be maintained during exercise and at rest;
2. Brain requires nutrients/glucose/oxygen;
3. Cognitive thought requires nutrients.
2 marks
(ii) 1.
2.
3.
4.
5.
6.
7.
8.
9.
Muscles need nutrients/oxygen to generate energy/work;
Stimulation by sympathetic nervous system;
Or adrenaline/noradrenaline is produced;
Controlled through arterioles;
By contraction of precapillary sphincters (control blood into capillaries);
Reduction of blood flow to the liver/kidneys/abdominal organs/gut;
Opening of vessels in the skeletal muscle/skin/Coronary circulation;
Vasoconstriction/vasodilation
This occurs due to drop in oxygen/rise in carbon dioxide levels/pH levels
drop/ increase in acidity/increase in temperature.
10. Detected by chemoreceptors;