Download Survival responses and cardiac control

Survival responses and cardiac control
Question Booklet
Name………………………………….…..
Target Grade…………………..
Grade achieved……………….
__/29
__%
Unit 5- Woodford County High School
Question 1
Unit 5- Woodford County High School
Unit 5- Woodford County High School
Question 2
Unit 5- Woodford County High School
Unit 5- Woodford County High School
Question 3
Unit 5- Woodford County High School
Unit 5- Woodford County High School
Question 4
Unit 5- Woodford County High School
Unit 5- Woodford County High School
5.
(a)
During a cardiac cycle, a wave of electrical activity spreads from the sino-atrial
node. Describe how the spread of this wave of electrical activity results in
(i)
the ventricles only contracting after they have filled with blood;
..........................................................................................................................
..........................................................................................................................
(1)
(ii)
the contraction of the ventricles starting at the apex of the heart.
..........................................................................................................................
..........................................................................................................................
(1)
Unit 5- Woodford County High School
(b)
The graphs show some of the pressure and volume changes that take place in the
left side of the heart during part of a cardiac cycle.
16
14
Key
12
Pressure/kPa
Aorta
Left ventricle
Left atrium
10
8
6
4
2
0
Time
130
120
Volume of
left ventricle/cm 3
110
100
90
80
70
60
A
B
Time
Using information from the graphs, describe the events which produce the change
in volume of blood in the ventricle between times A and B.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 5 mark)
Unit 5- Woodford County High School
6.
a)
The diagram shows a human heart.
Left atrium
Coronary artery
(i)
Use a guideline and label to show the position of the sinoatrial node (SAN).
(1)
(ii)
What is the function of the coronary artery?
............................................................................................................... (1)
(b) Impulses spread through the walls of the heart from the SAN. The table shows
the rate of conduction of impulses through various parts of the conducting
tissues.
Rate of conduction / m s–1
Mean distance / mm
From SAN to
atrioventricular node
(AVN) across atrium
1.0
40
Through AVN
0.05
5
From AVN to lower end
of bundle of His
1.0
10
Along Purkyne fibres
in ventricle walls
4.0
–
Part of pathway
Unit 5- Woodford County High School
(i)
Calculate the mean time taken for an impulse to pass from the SAN to the
lower end of the bundle of His. Show your working.
................................... s (2)
(ii)
Explain the advantage of the slow rate of conduction through the AVN.
.........................................................................................................................
.........................................................................................................................
..................................................................................................................(2)
(iii)
Suggest one advantage of the high rate of conduction in the Purkyne fibres
which carry impulses through the walls of the ventricles.
.................................................................................................................(1)
(c)
How would cutting the nerve connections from the brain to the SAN affect the
beating of the heart?
..................................................................................................................................
.......................................................................................................(1)(Total 8 marks)
7.
Although the heart does have a nerve supply, the role of the nervous system is not to
initiate the heartbeat but rather to modify the rate of contraction. The heart
determines its own regular contraction.
Describe how the regular contraction of the atria and ventricles is initiated and
coordinated by the heart itself.
..................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(5)
Unit 5- Woodford County High School
Mark Scheme
Question 1
Question 2
Unit 5- Woodford County High School
Question 3
Unit 5- Woodford County High School
Question 4
5.
(a)
(b)
(i)
Delay in spread of electrical activity at AV node/from atria to ventricle;
(ii)
Rapid spread of activity down ventricular septum/to base of ventricles/
along bundle of His/electrical activity travels up from base; 1
1
Ventricle contracts/systole;
Pressure increases in ventricle/pressure in ventricle higher than in aorta;
Valve between ventricle and aorta opens; 3
[5]
6.
(a)
(i)
guideline to upper part of right atrium;
(ii)
supply oxygen / nutrients to heart muscle / for contraction;
Unit 5- Woodford County High School
1
1
(b)
(i)
(ii)
(iii)
(c)
0.15s = 2 marks;
(working 0.04 + 0.10 + 0.01 = 1 mark)
(allow 1 mark for correct method dividing each distance by rate)
delays contraction of ventricles;
until after atria have contracted / ventricles filled;
2
2
rapid contraction of ventricles / both ventricles contract
together / rapid transmission to tip so contraction starts at
bottom of ventricles;
(reject strong contraction) 1
rate of heart beat not adjusted to activity / carries on beating at
constant rate / myogenic, so no effect;
(Accept: rate would increase because parasympathetic normally inhibits)
1
[8]
7.
(cardiac) muscle is myogenic;
sinoatrial node/SAN;
wave of depolarisation/impulses/electrical activity (across atria);
initiates contraction of atria
atrioventricular node/AVN;
bundle of His/purkyne tissue spreads impulse across ventricles;
ventricles contract after atria/time delay enables ventricles to fill;
Unit 5- Woodford County High School
[5]