Semester 2 Neuro, Week 2 - Cortex And Cortical Function

The primary auditory cortex is located in the temporal lobe. This lobe is responsible for processing auditory information such as sound perception and language comprehension. It is located on the sides of the brain, near the temples, and is involved in the interpretation of sound signals received from the ears.

A stroke in branches of the posterior cerebral artery affecting the majority of Brodmann's area 17 would result in disruptions in visual processing. Brodmann's area 17, also known as the primary visual cortex or V1, is responsible for processing visual information from the eyes. Damage to this area can lead to difficulties in perceiving and interpreting visual stimuli, such as recognizing objects, faces, or colors. This can manifest as visual field defects, visual hallucinations, or difficulty with visual perception tasks.

During his craniotomies, Wilder Penfield discovered that electrical stimulation of certain areas of the brain resulted in patients reporting hearing sounds or music. This suggests that these areas are involved in auditory processing. The areas 41 and 42 of Brodmann's map are known as the primary and secondary auditory cortices, respectively. These areas are responsible for processing sound information and are therefore best mapped for audition.

Broca's area is a region in the frontal lobe of the brain that is involved in speech production and language comprehension. It is commonly associated with the ability to articulate words and form sentences. Brodmann's numbers are a way of classifying different areas of the brain based on their cytoarchitecture. BA 44/45 refers to the specific region of the brain that corresponds to Broca's area. Therefore, BA 44/45 is the correct answer for the question.

Left hemineglect refers to a condition where individuals are unable to attend or respond to stimuli on the left side of their body or environment. This suggests a lesion or damage to the right hemisphere of the brain. The right hemisphere is responsible for processing information from the left side of the body and the left side of the environment. When this hemisphere is affected, individuals may fail to notice or acknowledge objects, people, or sensations on their left side. Therefore, the correct answer is the right hemisphere.

The hypothenar muscles receive a larger area of cortex when considering motor cortex somatotopy. This is because the hypothenar muscles are responsible for fine motor movements of the hand, such as controlling the movement of the little finger. These fine motor movements require more precise control and coordination, thus requiring a larger area of cortex for their representation.

The correct answer is "Difficulty hearing" because Brodmann's areas 41/42 are located in the auditory cortex of the brain, which is responsible for processing sound and speech. Therefore, damage to this area due to a stroke would likely result in difficulty hearing.

The left middle cerebral artery is the most likely artery to be compromised in this case. The middle cerebral artery supplies blood to the lateral surface of the brain, including the motor and sensory areas responsible for controlling movement and sensation in the contralateral (opposite) side of the body. Since the patient is unable to move his right upper limb and has lost sensation to that region, it suggests that the left middle cerebral artery, which supplies blood to the right side of the brain, is compromised.

The anterior paracentral lobule is responsible for controlling voluntary motor output to the lower extremities. Therefore, if this area is affected by a stroke, it is expected that the individual will exhibit a loss of voluntary motor output to the foot.

The asymmetry of the planum temporale surface is the anatomical marker of lateralization of language. This means that the left planum temporale is typically larger than the right planum temporale in individuals with language dominance in the left hemisphere. This structural difference suggests that the left hemisphere is specialized for language processing.

Layer V of the cerebral cortex is mostly composed of pyramidal cells. These cells have a triangular-shaped cell body and an apical dendrite that extends towards the surface of the cortex. They are involved in transmitting information from the cortex to other regions of the brain and are particularly important for motor control and higher cognitive functions.

The Planum temporale is the correct answer. The Planum temporale is an area of the brain that is involved in language functions. It has been found that there is a measurable volume difference between the right and left hemisphere of the brain in relation to the degree of lateralization of language functions. This suggests that the Planum temporale plays a role in the lateralization of language functions in the brain.

The role of the non-dominant equivalent to Wernicke area is related to prosodic aspects of language. Prosody refers to the rhythm, intonation, and stress patterns in speech, which play a crucial role in conveying meaning and emotions. The non-dominant equivalent to Wernicke area is responsible for processing and interpreting these prosodic cues in language. It helps individuals understand the emotional tone, emphasis, and melodic contours of speech, allowing for a deeper understanding of communication beyond just the words themselves.

The left dorsolateral prefrontal cortex is not involved in language for a person who is left-dominant. This area of the brain is responsible for executive functions such as decision-making, problem-solving, and working memory, but not specifically for language processing. Language processing is primarily associated with areas such as the left opercular gyrus, left angular gyrus, right plenum temporale, and right primary auditory cortex.