Question

Choose two parts of the brain and discuss how they might be related in function. How might a neuron in one structure depend for its function on what is happening in a neuron in the other structure?  Draw a conclusion about the way we localize functions in the brain: Was Broca justified in labeling a speech center in the brain with so few patients? How many brains are necessary to draw a conclusion? What does localization mean, after all? There is no strictly right or wrong answer to this question, but only thoughtful responses.

Describe an example in your own experience of misattributing a body function to a mental function or misattributing a mental function to a body function. For example, did doing chores as a kid really make you tired?

Answer 1

is the largest and most important part of the brain. It is also more complex than the other parts of the brain. The cerebrum consists of two symmetrical halves called the right and left ‘hemispheres’. The two hemispheres are connected at the bottom by a mass of white nerve fibers called corpus Callosum-sum. The right hemisphere is connected with the left side of the body and the left hemisphere with the right side of the body. The cerebrum contains within it grey matter and white matter. The grey matter is composed of nerve cells, while the white matter is made up of nerve fibers. The cerebrum is covered by a coating of the grey matter, and this coating is called the cortex. Within this cortex is the white substance. The cortex has many fissures and convolutions. Two of these fissures are anatomically important. These are known as the fissure of Rolando and fissure of Sylvius. These two fissures have divided each of the two hemispheres of the cerebrum into four areas or lobes, viz, - frontal, parietal, temporal and occipital.

Cerebrum controls the bodily and mental activities of human beings. Man’s superiority to other beings is due to his developed cerebrum. Cerebrum is the seat of sensations, thoughts, imagination, desire, etc. and of all that happens in our conscious life. Cerebrum initiates, assimilates, separates or obstructs, as the case may be, the activities that are constantly going on in the spinal cord, different parts of the brain and neurones. The cerebrum has three main areas-sensory area, motor area and association area. Afferent nerves coming from different parts of the body meet together in the sensory area of the cerebrum, and from the motor area of the cerebrum emerge innumerable efferent nerves connecting the different muscles of the body. The association area, which is also known as the silent area, harmonizes between the activities of the spinal cord and the lower region of the brain.

Mid-brain is situated between the cerebrum and cerebellum. It is situated just above and in front of the cerebellum. To speak more precisely, it is situated behind the brain-stem, the mid-brain is the base of the brain, and it has two important parts –thalamus and hypothalamus.

Thalamus discharges an important function in the case of lower animals, as this is the seat of experiences due to sensation. In the case of human beings, this function of the thalamus is mainly discharged by the cerebrum. In human beings, all the nerves pass through the thalamus to the cerebrum. Thalamus is mainly concerned with relaying afferent impulses on their way from the sense organs to the cerebral cortex. Hypothalamus, on the other hand, is concerned with the control and co-ordination of bodily functions involved in metabolism. Hypothalamus has also a special role in the expression of emotion.

Nerve cell is called neurone. The nervous system may, therefore, be said to be made up of innumerable neurones. Each neurone has three parts – (1) Cell body (2) and with this cell body is attached axon and (3) dendrites. Axon emerges from the cell and looks like a long, thin thread. Gradually it is covered by a sheath-like substance and then it is known as nerve fibre. Dendrite also emerges from the cell body and is like small twigs or branches of trees. Nerve fibre emerges from a cell and then it is divided into many branches and is thus reduced to what is known as dendrite. This dendrite connects itself with another dendrite of another cell. In this way the dendrites begin growing and ultimately become distributed in the various organs of the body. What is normally known as nerve is really a bundle of nerve fibers.

Localization is the ability of our nervous system to determine any sensation received by the nervous system.

Broca's area is a region in the prefrontal cortex that plays a role in the production of speech. It is justified as it is proved scientifically.