Physiology Data Analysis and Essay Questions (all topics)
2.
Draw a diagram of a villus in vertical section. (Total 5 marks)
3.
Carotenoids are plant pigments which occur in different forms, such as lutein (from spinach),
-carotene (from carrots), and lycopene (from tomatoes). Researchers investigated the processing
of carotenoids from vegetables in the stomach and small intestine. Healthy men were fed three test
meals differing only in the vegetable added. The carotenoid content of each test meal was the
same. Although the meals were basically liquid, the spinach meal had been made from chopped
spinach leaves. The meals were ingested in random order with three-week intervals between them.
Prior to the first meal, tubes leading directly into the stomach and small intestine were fitted to
each man. Samples of stomach and small intestine contents were collected from these tubes at
regular intervals after each meal. Data from this study is shown below.
60
30
Concentration of carotenoids
in the stomach / mol dm–3
Draw a diagram of the human digestive system. (Total 4 marks)
Concentration of carotenoids
in the stomach / mol dm–3
1.
50
40
30
20
10
0
Key:
0
60
120
Time / mins
= lutein (spinach meal)
180
25
20
15
10
5
0
0
= -carotene (carrot meal)
60
120
Time / mins
180
= lycopene (tomato meal)
[Source: Tyssandier et al, American Journal of Physiology, 284, (2003), pages 913–922. Copyright 2003 by
Am Physiological Society. Reproduced with permission of Am Physiological Soc via Copyright Clearance Center]
(a)
(i)
Calculate the rate of decrease of lycopene concentration in the period 60 minutes to
120 minutes after ingestion in the stomach.(1)
(ii)
Predict how many minutes from ingestion it will take lycopene to completely leave
the stomach.(1)
(b)
Describe the changes in stomach content of lutein,  -carotene and lycopene during the 180
minutes following ingestion.(2)
(c)
Suggest a reason why the concentration of lycopene stays relatively constant in the small
intestine.(1)
(Total 5 marks)
4.
(a)
Describe how the ileum uses active transport in the absorption of food.(3)
(b)
Outline how the blood is routed to the liver, through the liver, and from the liver.(3)
(c)
List two substances resulting from the breakdown of hemoglobin in the liver.(1)
(a)
List two glands that secrete digestive juices into the alimentary canal.(1)
(b)
Describe the process of erythrocyte and hemoglobin breakdown in the liver.(4)
(Total 7 marks)
5.
(Total 5 marks)
1
6.
Up to two additional marks are available for the construction of your answers. (2)
(a) Draw a diagram of the heart showing the chambers, valves and associated blood vessels.(4)
(b)
Outline the control of the heartbeat.(6)
(c)
Explain the relationship between the structure and function of blood vessels that are found in
a human. (8)
(Total 20 marks)
7.
Up to two additional marks are available for the construction of your answers.(2)
(a) List the characteristics of alveoli that permit efficient gas exchange.(4)
(b)
Describe the structures of arteries and veins as related to their functions.(6)
(c)
Explain the process of aerobic cell respiration.(8)
(a)
State the difference between an antigen and an antibody.(1)
(b)
Explain antibody production.(3)
(c)
State two other substances, apart from antibodies, transported by the blood. (1)
(Total 20 marks)
8.
(Total 5 marks)
9.
(a)
Explain how the skin and mucous membranes prevent entry of pathogens into the body. (3)
(b)
Explain why antibiotics are used to treat bacterial but not viral diseases.(2)
(Total 5 marks)
10.
Draw a diagram of the human gas exchange system.
11.
Explain the way the body acclimatizes to gas exchange at high altitudes.
12.
Explain how blood glucose concentration is controlled in humans.
13.
Explain the control of ADH secretion.
14.
(a)
Draw a labelled diagram of a nephron.(3)
(b)
Explain the process of ultrafiltration in the kidney. (3)
(c)
Compare the composition of blood plasma in the renal artery with the composition of the
glomerular filtrate.(2)
(Total 5 marks)
(Total 3 marks)
(Total 8 marks)
(Total 6 marks)
(Total 8 marks)
10
9
8
7
6
5
4
3
2
1
0
Plasma
ADH /
pmol dm–3
The plasma solute concentration, plasma antidiuretic hormone (ADH) concentration and feelings
of thirst were tested in a group of volunteers. These graphs show the relationship between intensity
of thirst, plasma ADH concentration and plasma solute concentration.
Intensity of
thirst / arbitrary
units
15.
280 290 300 310 320
Plasma solute concentration / mOsmol kg –1
20
18
16
14
12
10
8
6
4
2
0
280 290 300 310 320
Plasma solute concentration / mOsmol kg –1
[Source: adapted from C T Thompson, et al., (1986), Clinical Science London, 71, page 651]
2
(a)
Identify the plasma ADH concentration at a plasma solute concentration of 300 mOsmol kg–
1
using the line of best fit. (1)
(b)
Compare intensity of thirst and plasma ADH concentration.(1)
(c)
Outline what would happen to plasma solute concentration and ADH concentration if a
person were to drink water to satisfy his/her thirst.(2)
(d)
State two reasons why a person’s plasma solute concentration may increase.(2)
(Total 6 marks)
16.
Compare the processes of spermatogenesis and oogenesis.
17.
Explain how hormones control the menstrual cycle in human females.
18.
Describe the roles of nerves, muscles and bones in producing movement.
19.
Explain how pre-synaptic neurons can either encourage or inhibit post-synaptic transmission.
20.
Explain how skeletal muscle contracts.
(Total 7 marks)
(Total 8 marks)
(Total 6 marks)
(Total 6 marks)
(Total 9 marks)
3