| Date | May 2019 | Marks available | 4 | Reference code | 19M.3.SL.TZ2.7 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Explain | Question number | 7 | Adapted from | N/A |
Question
Explain the autonomic control of the pupil of the eye and how the pupil reflex is used to determine brain damage.
Markscheme
a. iris sphincter muscle / circular muscle / pupil constriction is controlled by the parasympathetic system ✔
b. iris dilator / radial muscle / pupil dilation is controlled by the sympathetic system ✔
c. at low light intensity pupil dilates
OR
at high intensity it constricts
OR
a reflex that controls the diameter of the pupil in response to intensity of light entering the eye ✔
d. «under normal conditions» pupils of both eyes respond identically to a light stimulus «regardless of which eye is being stimulated» ✔
e. response in one pupil without the other pupil responding is sign of a problem ✔
f. delayed response may indicate damage to brain / optic nerve / problems in oculomotor nerve/brain stem / use of depressant drugs / brain death ✔
Accept no response
Examiners report
Most candidates scored two marks for explaining the autonomic control of the pupil of the eye and how the pupil reflex is used to determine brain damage. The main error was mixing up the two autonomic systems. The answers were often scattered and confused.
Syllabus sections
- 18M.3.SL.TZ2.6c: Identify the area of the brain labelled X in the image.
- 18M.3.SL.TZ2.6b: Identify the area of the brain responsible for processing visual stimuli.
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18M.3.HL.TZ1.5c:
Outline the functional magnetic resonance imaging (fMRI) technique for brain research.
- 18M.3.SL.TZ2.5c: State the property of the nervous system that allows it to change with experience and allows...
- 18M.3.SL.TZ2.5b: Explain the use of the pupil reflex as a test for brain damage.
- 16N.3.HL.TZ0.5a: Outline the benefits of using fMRI in this experiment.
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17N.3.HL.TZ0.04b:
Suggest a role for the cerebral cortex in rodents such as rats and mice.
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20N.3.HL.TZ0.5a.ii:
State a function of the cerebellum.
- 19M.3.HL.TZ1.7a.ii: Outline how the diagram can be identified as a human brain and not the brain of a monkey.
- 17M.3.HL.TZ2.4b: The diagrams show a rat brain and a human brain. They are not drawn to scale. Distinguish...
- 19M.3.HL.TZ2.4b.iii: Suggest one reason for two different language groups being used in the study.
- 16N.3.HL.TZ0.5c: State the function of the visual cortex.
- 18N.3.SL.TZ0.6a.i: On the diagram, label the visual cortex.
- 18N.3.HL.TZ0.5b: Predict the difference that would be seen if the cerebral cortex of a human and a gorilla...
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18M.3.SL.TZ1.7:
Discuss the methods used to identify the role of specific parts of the brain.
- 17N.3.SL.TZ0.05b: Outline the reason that Broca’s area is more developed in humans than other primates.
- 20N.3.SL.TZ0.5b.ii: Information about the light from P entering the left eye is processed in the brain. State...
- 18N.3.HL.TZ0.5c.iii: State one function of each of the following areas of the brain. Medulla oblongata
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19M.3.HL.TZ1.7a.i:
Label the diagram to show part of the visual cortex of the brain.
- 18N.3.SL.TZ0.4a: The metabolic rate is the energy used per kilogram of mass per day. Calculate the metabolic...
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19M.3.SL.TZ2.5b:
Suggest one reason that the relative brain mass of Homo is different from Parapithecus and Australopithecus.
- 18N.3.SL.TZ0.6a.ii: Identify the structure labelled X.
- 17N.3.HL.TZ0.07c.i: State the area of the human brain that may have been damaged when the following symptom is...
- 17N.3.HL.TZ0.04a.i: State which group has the lowest percentage of cerebral cortex mass.
- 19M.3.HL.TZ2.4b.i: Identify the area of the brain which is labelled with the white arrow in the fMRI.
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16N.3.SL.TZ0.6a:
(i) Identify the structure labelled X.
(ii) Outline the function of X in the human brain
- 19M.3.SL.TZ1.4c: Explain how studies of lesions have helped to identify the functions of different parts of...
- 20N.3.HL.TZ0.5b: On the diagram, label one named structure that produces hormones.
- 18N.3.SL.TZ0.4b: Using only the data in the table, distinguish between the use of energy in the brain and in...
- 19M.3.HL.TZ2.4b.v: Suggest what might result if a deaf individual who uses sign language has a lesion in the...
- 18N.3.HL.TZ0.5c.i: State one function of each of the following areas of the brain. Broca’s area
- 17M.3.SL.TZ1.6b: Outline the function of Broca’s area.
- 17M.3.HL.TZ1.4e: State one activity controlled by the medulla oblongata.
- 17N.3.SL.TZ0.05c: Suggest how an injury to the brain can help in understanding brain function.
- 17N.3.HL.TZ0.07c.ii: State the area of the human brain that may have been damaged when the followingsymptom is...
-
17N.3.HL.TZ0.04c:
Explain how the cerebral cortex in humans differs from other mammals.
- 16N.3.HL.TZ0.6a: Outline the neural control of the process of swallowing.
- 18M.3.SL.TZ1.4b: Outline the function of the nucleus accumbens.
- 18M.3.SL.TZ1.4a: The image shows a normal human brain in vertical section. Identify the parts of the brain...
- 18M.3.HL.TZ1.5b: The brain requires a large energy input. Suggest one reason for this.
- 17M.3.SL.TZ2.5b: Evaluate the use of the pupil reflex to test for brain damage.
- 17N.3.SL.TZ0.05a.i: Identify the structure labelled A.
- 18M.3.SL.TZ2.6a: State the name of the technique used to produce the image.
- 19N.3.SL.TZ0.5a: Identify the structures found at I, II and III. I: II: III:
- 18M.3.HL.TZ2.5c: A person with Alzheimer’s disease typically has a reduced nucleus accumbens. Predict how this...
- 18M.3.HL.TZ2.5b: State the difference in the cerebral cortex between the two images of the brain.
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19M.3.SL.TZ2.5a:
State the trend in relative brain mass in primates other than humans according to their time of divergence from humans.
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18M.3.HL.TZ2.5a.i:
Label the cerebellum on image I.
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18N.3.SL.TZ0.6b:
Explain how a functional MRI (fMRI) can be used to identify the function of parts of the brain.
- 19N.3.HL.TZ0.4a: The human brain is larger than the brain of many animals. Identify one other difference...
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20N.3.SL.TZ0.5c:
State the type of cell in the retina which directly transmits impulses through the optic nerve to the brain.
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17N.3.HL.TZ0.04a.ii:
Suggest advantages of the cerebral cortex containing a high percentage of the brain’s neurons.
- 20N.3.SL.TZ0.5a: Draw a ray of light entering the left eye from point P.
- 20N.3.HL.TZ0.5a.i: Label the cerebellum on the diagram.
- 17M.3.SL.TZ1.5a: In a study of brain organization, several factors were investigated. The relationship between...
-
17M.3.HL.TZ2.8:
Explain two methods that scientists have used to determine the different functions of the brain.
- 19M.3.HL.TZ2.4b.iv: Outline how fMRI is used in brain studies.
- 20N.3.SL.TZ0.5b.i: Information about the light from P entering the left eye is processed in the brain. State...
- 19N.3.HL.TZ0.4c: State the name of the part of the brain that controls breathing rate.
- 17M.3.SL.TZ1.5c: Outline one reason for the large energy requirement of the brain.
- 18N.3.HL.TZ0.5a: Compare and contrast the rank order of body mass and brain volume in the six species of mammals.
- 18N.3.SL.TZ0.4c: Suggest one reason for the difference between the brain and skeletal muscle in metabolic rate.
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17N.3.SL.TZ0.05a.ii:
List two functions of the structure labelled A.
- 20N.3.HL.TZ0.5c: Outline one method that can be used to investigate the function of different parts of the brain.
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19M.3.SL.TZ1.4a:
State the name of the general area of the brain affected by this stroke.
- 17M.3.SL.TZ2.5a: Outline the function of the autonomic nervous system in the human body.
- 17M.3.SL.TZ2.6: The graph shows the relationship between body mass and brain volume in three groups of...
- 17M.3.SL.TZ2.8: Explain how information from the left and right sides of the visual field is processed.
- 16N.3.HL.TZ0.5b: Compare and contrast the effects of THC and CBD on the areas of the brain studied.
- 18M.3.SL.TZ1.4c: Compare and contrast the sensory and motor functions of the left and right cerebral...
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16N.3.SL.TZ0.6b:
With reference to structures visible in the diagrams, explain how the human brain is more evolved for higher order functions than the baboon brain.
- 18N.3.SL.TZ0.4d: Outline the role of the brain in involuntary control.
- 18N.3.HL.TZ0.5c.ii: State one function of each of the following areas of the brain. Nucleus accumbens
- 19M.3.HL.TZ2.4b.ii: Compare the general patterns of activation in the brain shown when all of the individuals in...
-
16N.3.SL.TZ0.7b:
Explain how the pupil of the eye can be used to assess brain damage.
- 19M.3.SL.TZ1.5a: Explain the neural control of swallowing.
- 19M.3.HL.TZ1.7b: Explain how studies of lesions have helped to identify the functions of different parts of...
-
19M.3.SL.TZ2.5c:
Deduce, with a reason, whether the relative brain mass is a good indicator of brain development.
- 17M.3.SL.TZ1.5b: Outline the organization of the human cerebral cortex with regard to structure and function.
- 19N.3.SL.TZ0.5c: The folding of the cerebral hemispheres is extensive and varies between different mammals....
- 19N.3.SL.TZ0.5b: Suggest one way in which multiple sclerosis has affected the cerebral hemispheres of the brain.
- 19N.3.HL.TZ0.4d: Explain the need for the adult human brain to be supplied continuously with a relatively...
-
18M.3.HL.TZ2.5d:
The images show the differences in glucose uptake between the brain of a person without Alzheimer’s disease (image I) and the brain of a patient with Alzheimer’s disease (image II). The key indicates the levels of glucose uptake.
Deduce the implications of reduced glucose uptake in the brain of a patient with Alzheimer’s disease.
- 20N.3.SL.TZ0.7: Explain how autopsy and lesions can be used to identify the role of different brain parts.
- 18M.3.HL.TZ2.5a.ii: State one function of the cerebellum.
- 17M.3.SL.TZ1.6a: The cortex of the brain consists of several regions. State whether this view of the brain...
