Neuro Cortex,Meninges,Ventricles MCQ's

An epidural hematoma is a collection of blood that forms between the skull and the dura mater, which is the tough outermost layer of the meninges. In this case, the head injury has caused bleeding between these two structures. The arachnoid and pia mater are inner layers of the meninges and are not involved in the accumulation of blood in an epidural hematoma.

The foramen of Megendie is the correct answer because it is the opening through which cerebrospinal fluid (CSF) flows from the fourth ventricle to the cistern magna. In hydrocephalus, the blockage of this foramen can lead to an accumulation of CSF in the ventricles, causing increased pressure and enlargement of the head. This condition is commonly seen in infants and young children.

Arachnoid villi are small, finger-like projections of the arachnoid mater (one of the layers of the meninges) into the dural sinuses. They act as one-way valves, allowing cerebrospinal fluid (CSF) to be absorbed from the subarachnoid space and returned back into the venous system. This process helps maintain the balance of CSF production and absorption, preventing an accumulation of fluid in the brain. Therefore, arachnoid villi are responsible for directly returning CSF to the venous system.

The primary auditory cortex is located in the temporal lobe. This lobe is responsible for processing auditory information and is involved in tasks such as hearing, language comprehension, and sound recognition. It receives information from the ears and interprets it, allowing us to perceive and understand sounds.

Based on the symptoms and test results described, the child most likely has bacterial meningitis. The increased proteins, decreased glucose levels, increased WBCs with increased polymorphs in the lumbar puncture indicate an inflammatory response in the cerebrospinal fluid. Bacterial meningitis is a serious infection of the meninges, the protective membranes surrounding the brain and spinal cord, and it can cause symptoms such as irritability and sensitivity to light. Prompt medical attention and treatment with antibiotics are crucial in cases of bacterial meningitis to prevent complications and potential life-threatening outcomes.

If the Foramen of Megendie is obstructed, it would lead to non-communicating hydrocephalus. The Foramen of Megendie is a small opening in the brain that allows cerebrospinal fluid (CSF) to flow from the ventricles into the subarachnoid space. When it is obstructed, CSF cannot flow properly, causing a buildup of fluid within the ventricles. This leads to increased pressure on the brain, resulting in hydrocephalus. In non-communicating hydrocephalus, the obstruction occurs within the ventricular system, preventing CSF from flowing between the ventricles and the subarachnoid space.

A stroke in branches of the posterior cerebral artery that affects the majority of Brodmann's area 17 would result in disruptions in visual processing. Brodmann's area 17 is the primary visual cortex, responsible for processing visual information. Damage to this area can lead to difficulties in visual perception, such as problems recognizing objects, faces, or colors, and may also cause visual hallucinations or visual field defects. Therefore, it is expected that this individual would exhibit disruptions in visual processing.

Wilder Penfield discovered that electrical stimulation of certain areas of the brain in conscious but anesthetized patients consistently generated reports of hearing familiar sounds or music. This suggests that these areas are involved in auditory perception. The best mapped areas for audition in the human cerebral cortex are areas 41 and 42 of Brodmann.

The correct answer is Foramen of Megendie. The question describes a situation where an infant's head size is larger than normal for her age, and radiological examination indicates obstruction of the medial foramen draining the fourth ventricle. The Foramen of Megendie, also known as the Median Aperture, is one of the three openings in the fourth ventricle that allows cerebrospinal fluid to flow out of the ventricles and into the subarachnoid space. Obstruction of this foramen can lead to the accumulation of cerebrospinal fluid in the ventricles, causing hydrocephalus and an enlarged head size.

The hypothenar muscles receive a larger area of cortex when considering motor cortex somatotopy. This is because the motor cortex somatotopy is organized in a way that assigns more cortical space to areas of the body that require more precise and fine motor control. The hypothenar muscles, located in the palm of the hand, are responsible for controlling the movements of the little finger and are involved in fine motor tasks such as writing or playing a musical instrument. Therefore, they require more precise control and thus receive a larger area of cortex.

The CSF (cerebrospinal fluid) flows from the 4th ventricle to the cistern magna via the median aperture. This is the correct answer because the question mentions that there is a tumor in the 4th ventricle, which could potentially obstruct the flow of CSF. The enlargement of all ventricles also suggests a problem with CSF circulation. The other options mentioned in the question are incorrect as they do not describe the normal flow of CSF in relation to the 4th ventricle.

Broca's area is a region in the frontal lobe of the brain that is responsible for language production and speech. It is commonly associated with the ability to articulate words and form sentences. Brodmann's numbers are a system used to classify different areas of the cerebral cortex based on their histological characteristics. BA 44/45 refers to the region of the brain that includes Broca's area. Therefore, the correct answer is BA 44/45.

The anterior paracentral lobule is responsible for controlling voluntary motor output to the lower limbs, specifically the foot. Therefore, damage to this area due to a stroke in the branches of the anterior cerebral artery would result in a loss of voluntary motor output to the foot. This means that the individual would have difficulty in moving or controlling their foot voluntarily.

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

The left 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 right upper limb. Therefore, if the man is unable to move his right upper limb and has lost sensation in that region, it suggests that the left middle cerebral artery is compromised.

Left hemineglect is a condition where individuals fail to attend or respond to stimuli presented on the left side of their visual field. This suggests a lesion in the right hemisphere of the brain. The right hemisphere is responsible for processing information from the left side of the body, including visual information. When this hemisphere is damaged, it can result in a neglect of the left side of space. Lesions in other areas such as the prefrontal cortex, optic nerve, or visual cortex would not specifically cause left hemineglect.

In a subarachnoid hemorrhage, there is bleeding into the subarachnoid space, which is the area between the arachnoid membrane and the pia mater surrounding the brain. This bleeding can be caused by the rupture of an aneurysm or a head injury. The presence of red blood cells in the cerebrospinal fluid obtained through lumbar puncture indicates bleeding in the subarachnoid space. Increased protein levels may be seen due to the breakdown of red blood cells. Normal glucose levels suggest that there is no disturbance in glucose metabolism. Therefore, the most likely findings in a lumbar puncture of a patient with subarachnoid hemorrhage are increased protein, normal glucose, and red blood cells.

The correct answer is asymmetry of planum temporale surface. The planum temporale is a region in the temporal lobe of the brain that is involved in language processing. In individuals with typical language lateralization, the planum temporale is larger in the left hemisphere compared to the right hemisphere. This asymmetry is thought to be a marker of the specialization of the left hemisphere for language functions.

Layer V of the cerebral cortex is mostly composed of pyramidal cells. Pyramidal cells are a type of neuron that have a triangular-shaped cell body and an apical dendrite that extends towards the surface of the cortex. These cells are known for their involvement in motor control, as they send signals from the cortex to other areas of the brain and spinal cord. Layer V is located deep within the cortex and is one of the main output layers, responsible for transmitting information from the cortex to subcortical structures and the spinal cord.

The correct answer is "More than one above." This is because neurons whose cell bodies are located in dorsal root ganglia have both peripheral and central nervous system components, and they are also pseudo-unipolar neurons.

Anencephaly is a neural tube defect that occurs when the cranial end of the neural tube fails to close during embryonic development. This results in the absence of a major portion of the brain, skull, and scalp. Despite the severe malformation, newborns with anencephaly may still display reflex activity because the brainstem, which controls basic reflexes, may still be partially intact. However, anencephaly is a fatal condition, and there is no cure or successful treatment with surgery. Additionally, anencephaly is associated with an increase in alpha-fetoprotein levels in the amniotic fluid and maternal blood.

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 working memory, decision-making, and problem-solving. Language processing is primarily associated with the left hemisphere of the brain, with areas such as the left opercular gyrus and left angular gyrus playing important roles. The right plenum temporale and right primary auditory cortex are involved in processing auditory information, but they are not specifically related to language processing.

A tumor in the cerebral aqueduct can block the flow of cerebrospinal fluid (CSF), leading to a non-communicating hydrocephalus. In this condition, the CSF accumulates in the ventricles of the brain, causing an increase in intracranial pressure. The increased pressure can cause a shift of the cranial contents in an inferior and medial direction, as the pressure pushes the brain downwards and towards the midline. This is the most likely finding in this man with a tumor in his cerebral aqueduct.

The area of the brain involved in language functions that exhibits measurable volume difference between the right and left hemisphere is called the Planum temporale. This area is known to be involved in various language processes such as speech perception, phonological processing, and language comprehension. The volume difference between the hemispheres is related to the degree of lateralization of these language functions, indicating that the Planum temporale plays a crucial role in language processing.

The non-dominant equivalent to Wernicke area is responsible for prosodic aspects of language. Prosody refers to the rhythm, intonation, and stress patterns in speech that convey meaning and emotion. It helps to convey the speaker's attitude, emphasis, and intentions. This area plays a crucial role in understanding and producing these prosodic features of language.