A.2 The human brain

IB Syllabus Statements

Understandings:

The anterior part of the neural tube expands to form the brain.
Different parts of the brain have specific roles.
The autonomic nervous system controls involuntary processes in the body using centres located mainly in the brain stem.
The cerebral cortex forms a larger proportion of the brain and is more highly developed in humans than other animals.
The human cerebral cortex has become enlarged principally by an increase in total area with extensive folding to accommodate it within the cranium.
The cerebral hemispheres are responsible for higher order functions.
The left cerebral hemisphere receives sensory input from sensory receptors in the right side of the body and the right side of the visual field in both eyes and vice versa for the right hemisphere.
The left cerebral hemisphere controls muscle contraction in the right side of the body and vice versa for the right hemisphere.
Brain metabolism requires large energy inputs.

Applications and skills:

Application: Visual cortex, Broca’s area, nucleus accumbens as areas of the brain with specific functions.
Application: Swallowing, breathing and heart rate as examples of activities coordinated by the medulla.
Application: Use of the pupil reflex to evaluate brain damage.
Application: Use of animal experiments, autopsy, lesions and fMRI to identify the role of different brain parts.
Skill: Identification of parts of the brain in a photograph, diagram or scan of the brain.
Skill: Analysis of correlations between body size and brain size in different animals.

Explain what is represented by the sensory homunculus and the motor homunculus.
Explain how the brain is formed.
Outline the roles of different parts of the brain, and how some activities are spread in many areas.
Explain the role of the autonomic nervous system.
What is the cerebral cortex, and compare it in humans and other animals.
Explain the importance of the extensive folding in the human cerebral cortex.
What are cerebral hemispheres responsible for?
Compare where the left cerebral hemisphere receives sensory input and controls muscle contraction, to that of the right cerebral hemisphere.
Explain what is required by brain metabolism.
Explain how the definition of living varies depending on local and natural laws, and culture.
What is Angelman syndrome and how is it diagnosed using an electroencephalogram?
Outline the specific functions of the visual cortex, Broca’s area, and nucleus accumbens.
What are examples of activities coordinated by the medulla?
Outline how the pupil reflex can evaluate brain damage.
Explain how the use of animal experiments, autopsy, lesions, and fMRI can identify the role of different parts of the brain.
Explain how you would identify parts of the brain in a photograph, diagram, or scan of the brain, including the medulla oblongata, cerebellum, hypothalamus, pituitary gland and cerebral hemispheres.
Explain how you would analyze correlations between body size and brain size in different animals.