Neuro I Exam II
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neuro
- 1.
Where is serotonin (5-HT) synthesized?
- A.
Raphe nuclei of midbrain, pons, medulla
- B.
Ventral Tegmental area
- C.
Nucleus (locus) coeruleus
- D.
Medulla oblongota
Correct Answer
A. RapHe nuclei of midbrain, pons, medullaExplanation
Serotonin, also known as 5-HT, is synthesized in the raphe nuclei of the midbrain, pons, and medulla. These regions of the brain are responsible for producing and releasing serotonin, which plays a crucial role in regulating mood, appetite, sleep, and other important physiological functions. The raphe nuclei are a group of nuclei located along the midline of the brainstem, and they are the primary source of serotonin in the central nervous system.Rate this question:
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- 2.
Where is dopamine not synthesized?
- A.
Ventral tegmental area
- B.
Substanita nigra
- C.
Retina
- D.
Tubero-infundibular system
- E.
Nucleus of Mynert
Correct Answer
E. Nucleus of MynertExplanation
The correct answer is the nucleus of Mynert. Dopamine is synthesized in various regions of the brain, including the ventral tegmental area, substantia nigra, and tubero-infundibular system. However, it is not synthesized in the nucleus of Mynert.Rate this question:
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- 3.
Where is norepinephrine synthesized?
- A.
Raphe nuclei
- B.
Ventral tegmental area
- C.
Nucleus of mynert
- D.
Nucleus coeruleus
Correct Answer
D. Nucleus coeruleusExplanation
Norepinephrine is synthesized in the nucleus coeruleus. This region of the brainstem is responsible for producing and releasing norepinephrine, which is a neurotransmitter involved in various functions such as regulating mood, attention, and arousal. The nucleus coeruleus is located in the pons, near the fourth ventricle, and sends projections to different areas of the brain, including the cortex, hippocampus, and spinal cord.Rate this question:
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- 4.
Where is acetylcholine synthesized?
- A.
Raphe nuclei
- B.
Nucleus of mynert
- C.
Nucleus coeruleus
- D.
Ventral tegmental area
Correct Answer
B. Nucleus of mynertExplanation
Acetylcholine is synthesized in the nucleus of Mynert.Rate this question:
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- 5.
This tract is responsible for unconscious proprioceptive information from the upper extremeities and is an analog to DSCT.
- A.
Cuneocerebellar tract
- B.
Spinotectal tract
- C.
Spinoreticular tract
- D.
Corticospinal tract
Correct Answer
A. Cuneocerebellar tractExplanation
The cuneocerebellar tract is responsible for transmitting unconscious proprioceptive information from the upper extremities. It is considered an analog to the DSCT (dorsal spinocerebellar tract). The DSCT carries proprioceptive information from the lower extremities, while the cuneocerebellar tract specifically deals with the upper extremities. This tract helps provide the cerebellum with information about the position and movement of the arms and hands, allowing for coordinated motor control.Rate this question:
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- 6.
This tract is responsible for orienting the eyes and head towards a stimulus
- A.
Cuneocerebellar tract
- B.
Spinotectal tract
- C.
Spinoreticular tract
- D.
Spinocerebellar tract
Correct Answer
B. Spinotectal tractExplanation
The spinotectal tract is responsible for orienting the eyes and head towards a stimulus. This tract carries sensory information from the spinal cord to the superior colliculus in the midbrain, which then coordinates the movement of the eyes and head in response to the stimulus. The cuneocerebellar tract carries proprioceptive information from the upper limbs to the cerebellum, the spinoreticular tract carries pain and temperature information to the reticular formation in the brainstem, and the spinocerebellar tract carries proprioceptive information from the lower limbs to the cerebellum.Rate this question:
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- 7.
This tract is responsible for perception of visceral pain, postural control and orientation
- A.
Cuneocerebellar tract
- B.
Spinotectal tract
- C.
Spinoreticular tract
- D.
Corticospinal tract
Correct Answer
C. Spinoreticular tractExplanation
The spinoreticular tract is responsible for the perception of visceral pain, postural control, and orientation. It carries sensory information from the spinal cord to the reticular formation in the brainstem. The reticular formation plays a crucial role in regulating arousal, attention, and consciousness. Therefore, the spinoreticular tract is involved in transmitting pain signals from internal organs, maintaining balance and posture, and helping us orient ourselves in space.Rate this question:
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- 8.
This tract is responsible for touch perception, proprioception and vibration
- A.
Dorsal column medial meniscus pathway
- B.
Ventral spinothalamic tract
- C.
Lateral spinothalamic tract
- D.
Dorsal spinocerebellar tract
Correct Answer
A. Dorsal column medial meniscus pathwayExplanation
The correct answer is the dorsal column medial meniscus pathway. This tract is responsible for touch perception, proprioception, and vibration. It carries sensory information from the body to the brain, specifically to the somatosensory cortex. The dorsal column medial meniscus pathway consists of two tracts: the fasciculus gracilis, which carries information from the lower body, and the fasciculus cuneatus, which carries information from the upper body. Together, they transmit sensory signals related to touch, position sense, and vibration to the brain for interpretation and perception.Rate this question:
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- 9.
Progressive multifocal leukoencephalopathy is a viral encephalitis which causes demyelination by preferential infection of
- A.
Neurons
- B.
Astrocytes
- C.
Oligodendrocytes
- D.
Schwann Cells
Correct Answer
C. OligodendrocytesExplanation
Progressive multifocal leukoencephalopathy is a viral encephalitis that specifically infects oligodendrocytes. Oligodendrocytes are responsible for producing the myelin sheath, which insulates and protects nerve fibers in the central nervous system. By preferentially infecting oligodendrocytes, the virus disrupts the production and maintenance of myelin, leading to demyelination. This results in impaired nerve function and the symptoms associated with progressive multifocal leukoencephalopathy.Rate this question:
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- 10.
Microscopically, active plaques of multiple sclerosis show
- A.
Macrophages with lipids (myelin breakdown products), and perivascular mononuclear inflammatory cell
- B.
Abundant neutrophils with tissue necrosis and neuronal cell death
- C.
Sparse myelin, reduction in number of oligodendrocyte nuclei, and gliosis with astrocytic proliferation
- D.
Edema and vascular proliferation associated with demyelination
- E.
Viral particles
Correct Answer
A. MacropHages with lipids (myelin breakdown products), and perivascular mononuclear inflammatory cellExplanation
The correct answer is "Macrophages with lipids (myelin breakdown products), and perivascular mononuclear inflammatory cells." This answer is supported by the description of active plaques of multiple sclerosis showing the presence of macrophages containing lipids, which are breakdown products of myelin. Additionally, the presence of perivascular mononuclear inflammatory cells suggests an inflammatory response in these plaques. This explanation is consistent with the known pathology of multiple sclerosis, which involves the destruction of myelin in the central nervous system.Rate this question:
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- 11.
Which demyelinating leukodystrophy is characterized by the microscopic presence of macrophages filled with cerbroside, forming multinucleated cells around blood vessels, also known as “globoid” cells
- A.
Metachromatic leukodystrophy
- B.
Krabbe's Disease
- C.
Progressive multifocal leukodystrophy
- D.
Pick's disease
Correct Answer
B. Krabbe's DiseaseExplanation
Krabbe's Disease is the correct answer because it is a demyelinating leukodystrophy that is characterized by the presence of macrophages filled with cerbroside, forming multinucleated cells around blood vessels, also known as "globoid" cells. This accumulation of cerbroside leads to the destruction of the myelin sheath in the nervous system, resulting in neurological symptoms. Metachromatic leukodystrophy is also a demyelinating leukodystrophy, but it is characterized by the accumulation of sulfatides, not cerbroside. Progressive multifocal leukodystrophy and Pick's disease are unrelated conditions and do not involve the presence of macrophages filled with cerbroside.Rate this question:
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- 12.
The following neurotransmitter is distributed in the midbrain, ventral tegmental area and hypothalamus. The functions of this neurotransmitter range from pleasure and reward, to movement, attention and memory. In addition, cocaine, amphetamine and methamphetamine directly or indirectly augment the levels of this neurotransmitter in the brain’s reward pathway:
- A.
Epinephrine
- B.
Norepinephrine
- C.
Dopamine
- D.
Acetylcholine
Correct Answer
C. DopamineExplanation
Dopamine is the correct answer because it is distributed in the midbrain, ventral tegmental area, and hypothalamus. It plays a role in pleasure, reward, movement, attention, and memory. Drugs like cocaine, amphetamine, and methamphetamine increase the levels of dopamine in the brain's reward pathway.Rate this question:
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- 13.
A 70-year-old woman with dementia and clinical symptoms consistent with Alzheimer’s disease expires in a nursing home. At autopsy, pathological examination of the brain reveals cortical atrophy affecting the frontal, parietal, and temporal lobes. Microscopic examination of the brain sections show changes confirming the clinical diagnosis. Which of the following histological findings contains an abnormally hyperphosphorylated form of the tau protein
- A.
Amyloid angiopathy
- B.
Hirano bodies
- C.
Granulovacular degeneration
- D.
Neurofibrillary tangles
- E.
Neuritic plaques
Correct Answer
D. Neurofibrillary tanglesExplanation
Neurofibrillary tangles are histological findings that contain an abnormally hyperphosphorylated form of the tau protein. In this case, the 70-year-old woman with dementia and clinical symptoms consistent with Alzheimer's disease had cortical atrophy affecting the frontal, parietal, and temporal lobes, which is characteristic of Alzheimer's disease. The microscopic examination of the brain sections confirmed the clinical diagnosis, and the presence of neurofibrillary tangles is consistent with Alzheimer's disease.Rate this question:
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- 14.
A 65-year-old man with masked facies, shuffling gait, and pill-rolling tremor dies secondary to respiratory failure. At autopsy, examination of his brain shows loss of pigmentation in the substantia nigra and the presence of Lewy bodies. What protein would most likely be found within the Lewy bodies
- A.
Amyloid precursor protein
- B.
Alpha synuclein
- C.
Beta A4 amyloid
- D.
Hyperphosphorylated tau
- E.
Glial fibrillary associated protein
Correct Answer
B. AlpHa synucleinExplanation
The presence of Lewy bodies in the brain is a characteristic finding in Parkinson's disease. Lewy bodies are abnormal protein aggregates that are primarily composed of alpha synuclein. Therefore, the protein that would most likely be found within the Lewy bodies in this case is alpha synuclein.Rate this question:
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- 15.
Upon histological examination of the brain of a patient with dementia, a pathologist notes focal spherical collections of dilated, tortuous, silver staining processes around a central amyloid core surrounded by a clear halo. What would best describe these structures
- A.
Amyloid angiopathy
- B.
Hirano bodies
- C.
Lewy bodies
- D.
Neuritic plaques
Correct Answer
D. Neuritic plaquesExplanation
The description of focal spherical collections of dilated, tortuous, silver staining processes around a central amyloid core surrounded by a clear halo is characteristic of neuritic plaques. Neuritic plaques are a hallmark pathological feature of Alzheimer's disease and are composed of beta-amyloid protein deposits surrounded by dystrophic neurites. These plaques are commonly found in the brains of patients with dementia. Amyloid angiopathy refers to the deposition of amyloid protein in the walls of blood vessels in the brain. Hirano bodies are eosinophilic inclusion bodies found in the neurons of patients with neurodegenerative diseases. Lewy bodies are intracellular protein aggregates found in the brains of patients with Parkinson's disease and Lewy body dementia.Rate this question:
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- 16.
A 45-year-old HIV positive man presents with dementia of slow onset and progression, consistent with AIDS-dementia complex. What microscopic change in the brain would best characterize this illness
- A.
Amyloid angiopathy
- B.
Kuru plaques
- C.
Microglial nodules
- D.
Neuritic plaques
- E.
Neurofibrillary tangles
Correct Answer
C. Microglial nodulesExplanation
Microglial nodules would best characterize AIDS-dementia complex. In this condition, HIV infection leads to inflammation in the brain, causing the activation of microglial cells, which are the resident immune cells in the central nervous system. These activated microglial cells form nodules, which are clusters of cells that can be seen under microscopic examination. This finding is characteristic of AIDS-dementia complex and helps differentiate it from other neurodegenerative diseases.Rate this question:
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- 17.
A 75-year-old man with long standing diabetes presents with a non-healing ulcer on his lower extremity. Microscopic examination of the endoneurial arterioles in this region would reveal them to be
- A.
Thin and dilated
- B.
Thick and hyalinized
- C.
Infiltrated by lymphocytes and plasma cells
- D.
Involved by tumors
- E.
Myelinated
Correct Answer
B. Thick and hyalinizedExplanation
The correct answer is "thick and hyalinized." In a 75-year-old man with long standing diabetes, the non-healing ulcer on his lower extremity suggests the presence of peripheral vascular disease. Thickening and hyalinization of the endoneurial arterioles is a characteristic finding in this condition. This thickening and hyalinization can lead to reduced blood flow to the affected area, impairing wound healing and causing the ulcer to persist.Rate this question:
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- 18.
Which is the key event in long-term potentiation (LTP) that specifically facilitates the postsynaptic influx of calcium ions (Ca2+) through an otherwise blocked ion channel?
- A.
Postsynaptic depolarization
- B.
Presynaptic glutamate release
- C.
Binding of glutamate to NMDA receptors
- D.
Na efflux through AMPA receptors
- E.
Binding of Mg to AMPA receptors
Correct Answer
A. Postsynaptic depolarizationExplanation
The key event in long-term potentiation (LTP) that specifically facilitates the postsynaptic influx of calcium ions (Ca2+) through an otherwise blocked ion channel is postsynaptic depolarization. When the postsynaptic membrane depolarizes, it removes the block on the NMDA receptors, allowing calcium ions to enter the postsynaptic neuron. This influx of calcium ions is crucial for the signaling pathways that lead to the strengthening of the synaptic connection and the formation of long-term memories.Rate this question:
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- 19.
What is the pathway through which the glutamatergic theory explains the onset of neuronal death leading to Alzheimer’s Disease?
- A.
Lack of neurotransmitter leading to postsynaptic silencing
- B.
Prolonged postsynaptic ion influx leading to excitotoxicity
- C.
Malfunction of apolipoprotein E4 (APOE-4) causing hypocholesteremia
- D.
Mitochondrial oxidative stress leading to neuronal apoptosis
Correct Answer
B. Prolonged postsynaptic ion influx leading to excitotoxicityExplanation
The glutamatergic theory proposes that prolonged postsynaptic ion influx can lead to excitotoxicity, which is the excessive stimulation of neurons by the neurotransmitter glutamate. This excessive stimulation can cause an influx of calcium ions into the neurons, leading to cell damage and ultimately neuronal death. In the context of Alzheimer's disease, this pathway suggests that excessive glutamate activity and excitotoxicity contribute to the death of neurons, leading to the onset of the disease.Rate this question:
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- 20.
Prostaglandins are synthesized from unsaturated fatty acids. Inhibition of which enzyme would decrease prostaglandin synthesis
- A.
Phospholipase A1
- B.
Phospholipase A2
- C.
Phospholipase C
- D.
Phospholipase D
- E.
Colipase
Correct Answer
B. pHospHolipase A2Explanation
Phospholipase A2 is the correct answer because it is the enzyme responsible for releasing arachidonic acid from cell membrane phospholipids, which is the precursor for prostaglandin synthesis. Inhibiting phospholipase A2 would therefore decrease prostaglandin synthesis.Rate this question:
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- 21.
A 6-month-old male patient shows developmental deficits and poor motor skills. After an examination, you suspect Niemann Pick disease. A molecular finding often associated with some types of Niemann Pick disease is
- A.
A decrease in sphingomyelinase activity and increased accumulation of sphingomyelin
- B.
An increase in ceramidase activity and increased accumulation of ceramide
- C.
A decrease in ceramidase activity and increased accumulation of ceramid
- D.
An increase in sphingomyelinase activity and decreased accumulation of sphingomyelin
- E.
An increase in ceramidase and sphingomyelinase activity
Correct Answer
A. A decrease in spHingomyelinase activity and increased accumulation of spHingomyelinExplanation
Niemann Pick disease is a rare genetic disorder characterized by the accumulation of sphingomyelin in the cells. Sphingomyelinase is the enzyme responsible for breaking down sphingomyelin. In this disease, there is a decrease in the activity of sphingomyelinase, leading to the accumulation of sphingomyelin. Therefore, the correct answer is a decrease in sphingomyelinase activity and increased accumulation of sphingomyelin.Rate this question:
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- 22.
Poor development of peroxisomes due to genetic causes, as in Zellweger syndrome, is associated with decreased synthesis of
- A.
Plasmalogen
- B.
Phosphatidic acid
- C.
Phosphatidylcholine
- D.
Cerebroside
- E.
Cardiolipin
Correct Answer
A. PlasmalogenExplanation
Poor development of peroxisomes due to genetic causes, such as in Zellweger syndrome, is associated with decreased synthesis of plasmalogen.Rate this question:
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- 23.
A lipid whose headgroup is a significant second messenger is
- A.
Phosphatidylcholine
- B.
Phosphatidylethanolamine
- C.
Phosphatydylglycerol
- D.
Phosphatidic acid
- E.
Phosphatydininisotil
Correct Answer
E. pHospHatydininisotilExplanation
Phosphatidylinositol is a lipid whose headgroup is a significant second messenger. It is involved in various cellular processes, including signal transduction, cell growth, and differentiation. Phosphatidylinositol can be phosphorylated at different positions on its inositol ring, leading to the production of different phosphoinositides, which act as second messengers in intracellular signaling pathways. These phosphoinositides play crucial roles in regulating cellular functions and are involved in processes such as membrane trafficking, cytoskeleton organization, and cell survival.Rate this question:
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- 24.
A 45-year-old male AIDS patient develops viral encephalitis consistent with progressive multifocal leukoencephalopathy. A CT scan shows multiple areas of demyelination. A confirmatory brain biopsy is performed. An electron microscope study shows oligodendrocytes containing what structures within their nuclei
- A.
Corpora amylace
- B.
Herpes virus particle
- C.
HIV virus particle
- D.
JC virus particles
Correct Answer
D. JC virus particlesExplanation
The correct answer is JC virus particles. Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal brain infection that occurs in individuals with weakened immune systems, such as AIDS patients. It is caused by the JC virus, which infects oligodendrocytes, the cells responsible for producing myelin in the central nervous system. The presence of JC virus particles within the nuclei of oligodendrocytes confirms the diagnosis of PML.Rate this question:
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- 25.
A 70-year-old woman with dementia and clinical symptoms consistent with Alzheimer’s disease expires in a nursing home. At autopsy, pathological examination of the brain reveals cortical atrophy affecting the frontal, parietal, and temporal lobes. Microscopic examination of the brain sections show changes confirming the clinical diagnosis. Which of the following histological findings, though not specific to Alzheimer’s disease, correlates best with the degree of dementia
- A.
Amyloid angiopathy
- B.
Hirano bodies
- C.
Granulovascular degeneration
- D.
Neurofibrillary tangles
- E.
Neuritic plaques
Correct Answer
D. Neurofibrillary tanglesExplanation
Neurofibrillary tangles are intracellular aggregates of hyperphosphorylated tau protein that are commonly seen in Alzheimer's disease. The degree of neurofibrillary tangles correlates with the severity of dementia in Alzheimer's disease. Although neurofibrillary tangles are not specific to Alzheimer's disease, they are a key pathological feature and play a significant role in the development and progression of the disease.Rate this question:
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- 26.
Upon histological examination of the brain of a patient with dementia, a pathologist notes focal spherical collections of dilated, tortuous, silver staining processes around a central amyloid core surrounded by a clear halo. What is the dominant component of the amyloid core
- A.
Alpha synuclein
- B.
Amyloid precursor protein
- C.
Abeta peptide
- D.
Myelin
- E.
Actin filaments
Correct Answer
C. Abeta peptideExplanation
The dominant component of the amyloid core in the brain of a patient with dementia is the abeta peptide. This is indicated by the presence of focal spherical collections of dilated, tortuous, silver staining processes around the central amyloid core, surrounded by a clear halo.Rate this question:
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- 27.
Neurons in the pars reticulata division of the substantia nigra project to which of the following areas?
- A.
Caudate
- B.
Putamen
- C.
Globus pallidus
- D.
Thalamus
- E.
Nucelus acuumbens
Correct Answer
D. ThalamusExplanation
Neurons in the pars reticulata division of the substantia nigra project to the thalamus. The substantia nigra is a midbrain structure involved in the regulation of movement. The pars reticulata division of the substantia nigra is responsible for inhibiting the activity of the thalamus. This inhibition helps to regulate motor output and prevent unwanted movements. Therefore, the correct answer is thalamus.Rate this question:
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- 28.
Which of the following structures is part of the epithalamus
- A.
Superior colliculus
- B.
Hypothalamus
- C.
Ventral tegmental area
- D.
Periaqueductal gray
- E.
Habenula
Correct Answer
E. HabenulaExplanation
The habenula is a small structure located in the epithalamus, which is a region of the brain. It is responsible for regulating various functions such as sleep-wake cycles, reward processing, and stress responses. The other options listed are not part of the epithalamus. The superior colliculus is part of the midbrain, the hypothalamus is a separate region responsible for regulating bodily functions, the ventral tegmental area is part of the mesencephalon, the periaqueductal gray is part of the midbrain, and the habenula itself is part of the epithalamus.Rate this question:
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- 29.
Which of the following structures is medial to the internal capsule
- A.
Head of caudate
- B.
Tail of caudate
- C.
Putamen
- D.
Thalamus
Correct Answer
A. Head of caudateExplanation
The head of the caudate is the correct answer because it is located in the medial aspect of the internal capsule. The internal capsule is a white matter structure in the brain that separates the caudate nucleus and the thalamus from the putamen. The head of the caudate is positioned closer to the midline of the brain, making it medial to the internal capsule.Rate this question:
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- 30.
Neurons in Brodmann’s area 42 will increase their activity during which of the following conditions
- A.
Visual stimulation
- B.
Auditory stimulation
- C.
Voluntary movement
- D.
Smell
Correct Answer
B. Auditory stimulationExplanation
Neurons in Brodmann's area 42 will increase their activity during auditory stimulation. This is because Brodmann's area 42, also known as the primary auditory cortex, is responsible for processing auditory information. When there is auditory stimulation, such as hearing a sound or a voice, the neurons in this area become more active in order to process and interpret the auditory signals.Rate this question:
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- 31.
The cortical neurons that project to the thalamus are located in which of the following laminae
- A.
I
- B.
II
- C.
III
- D.
IV
- E.
V
Correct Answer
E. VExplanation
The cortical neurons that project to the thalamus are located in lamina V.Rate this question:
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- 32.
Which of the following structures has been implicated in addiction
- A.
Inferotemporal cortex
- B.
Parietal cortex
- C.
Red nucleus
- D.
Substantia nigra
- E.
Ventral tegmental area
Correct Answer
E. Ventral tegmental areaExplanation
The ventral tegmental area (VTA) has been implicated in addiction. It is a region in the midbrain that plays a crucial role in the brain's reward system. The VTA contains dopamine neurons that project to various areas of the brain, including the nucleus accumbens, prefrontal cortex, and amygdala, which are all involved in the experience of reward and reinforcement. Activation of the VTA and the release of dopamine in these target regions are associated with the pleasurable effects of drugs and other addictive substances, leading to the development of addiction.Rate this question:
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- 33.
You are trying to build a model bilayer membrane using a single lipid variety to evaluate potential drugs. The bilayer should have the lowest possible net charge at neutral pH and very low ionic strength. The best choice of lipid for such a model membrane is
- A.
Cardiolipin
- B.
Phosphatidic acid
- C.
Phosphatidyl ethanolamine
- D.
Phosphatidyl serine
- E.
Phosphatidyl inositol triphosphate
Correct Answer
C. pHospHatidyl ethanolamineExplanation
Phosphatidyl ethanolamine is the best choice of lipid for building a model bilayer membrane with the lowest possible net charge at neutral pH and very low ionic strength. This is because phosphatidyl ethanolamine is a zwitterionic lipid, meaning it has both a positively charged amino group and a negatively charged phosphate group. These charges cancel each other out, resulting in a neutral net charge. Additionally, phosphatidyl ethanolamine is commonly found in biological membranes, making it a suitable choice for modeling a natural membrane environment.Rate this question:
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- 34.
One of your patients suffers from fatty liver; you suspect that lipid export by the liver has been compromised. One possible contributor to such limitation of the liver’s ability to export lipids may be
- A.
Decreased availability of choline
- B.
Decreased activity intestinal lipase
- C.
Increased activity phosphatidylethanolamine-methyltransferase
- D.
Increased availabilty diacyl glycerol
- E.
Increased availability of phosphatidylethanolamin
Correct Answer
A. Decreased availability of cholineExplanation
A decreased availability of choline could contribute to a limitation of the liver's ability to export lipids. Choline is an essential nutrient that is required for the synthesis of phosphatidylcholine, a major component of lipoproteins that transport lipids out of the liver. If there is a decreased availability of choline, it could lead to a decrease in the synthesis of phosphatidylcholine, thereby impairing the liver's ability to export lipids.Rate this question:
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- 35.
Decarboxylases often use vitamin B6 (pyridoxine) as a coenzyme. Vitamin B6 deficiency can be expected to decrease our ability to convert
- A.
Cardiolipin to diacylglycerol
- B.
Choline to CDP-Choline
- C.
Diacylglycerol to CDP-diacylglycerol
- D.
Phosphatidyl ethanolamine to phosphatidyl choline
- E.
Phosphatidyl serine to phosphatidyl ethnolamine
Correct Answer
E. pHospHatidyl serine to pHospHatidyl ethnolamineExplanation
Decarboxylases are enzymes that remove a carboxyl group from a molecule. Vitamin B6 is often used as a coenzyme by decarboxylases, meaning it helps the enzyme carry out its function. In this case, a deficiency in vitamin B6 would decrease the activity of decarboxylases. Phosphatidyl serine and phosphatidyl ethanolamine are both phospholipids, and the conversion of phosphatidyl serine to phosphatidyl ethanolamine requires a decarboxylase enzyme. Therefore, a deficiency in vitamin B6 would be expected to decrease the ability to convert phosphatidyl serine to phosphatidyl ethanolamine.Rate this question:
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- 36.
One of your patients, a new-born, shows impaired motor ability and difficulty with swallowing. You suspect Farber’s Disease. Farber’s disease will likely be commonly associated with
- A.
Decreased concentration of Ceramides in the system
- B.
Decreased concentration of Plasmalogens in the system
- C.
Defects in the Ceramidase gene
- D.
Inability to absorb Choline from diet
- E.
Increased Sphingomyelinase activity
Correct Answer
C. Defects in the Ceramidase geneExplanation
Farber's disease is a rare genetic disorder characterized by the accumulation of fatty substances called ceramides in various tissues and organs of the body. The impaired motor ability and difficulty with swallowing seen in the newborn patient suggest a neurological involvement, which is consistent with Farber's disease. Defects in the Ceramidase gene, which encodes an enzyme involved in the breakdown of ceramides, would lead to a decreased ability to break down ceramides, resulting in their accumulation and the symptoms observed in the patient. Therefore, the correct answer is defects in the Ceramidase gene.Rate this question:
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- 37.
The long-term memory of procedural skills and habits is mostly stored in the
- A.
Frontal cortex
- B.
Hippocamus
- C.
Striatum
- D.
Medial temporal lobe
Correct Answer
C. StriatumExplanation
The correct answer is the striatum. The striatum is responsible for storing long-term memory of procedural skills and habits. This region of the brain is involved in the formation and retrieval of habits and repetitive behaviors. It plays a crucial role in motor control and procedural learning, making it the most likely location for the storage of these types of memories. The frontal cortex is involved in higher cognitive functions but not specifically in the storage of procedural memories. The hippocampus and medial temporal lobe are more involved in the formation and retrieval of declarative memories.Rate this question:
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- 38.
The perforant pathway
- A.
Connects to the contralateral hippocampus
- B.
Ends at the medial mammillary nucleus
- C.
Ends at the ventromedial nucleus of the hypothalamus
- D.
Is directed toward the hippocampus (afferent)
- E.
Is part of the fimbria-fornix pathway
Correct Answer
D. Is directed toward the hippocampus (afferent)Explanation
The perforant pathway is a neural pathway that carries information from the entorhinal cortex to the hippocampus. It is an afferent pathway, meaning it is directed towards the hippocampus. The other options provided in the question are not accurate descriptions of the perforant pathway.Rate this question:
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- 39.
The midbrain includes the following structures:
- A.
Trochlear and hypoglossal nuclei
- B.
Substantia nigra and PAG
- C.
Superior olivary complex
- D.
Spinal trigeminal nucleus
- E.
Vestibular nuclei and sensory decussation
Correct Answer
B. Substantia nigra and PAGExplanation
The substantia nigra and PAG (periaqueductal gray) are both structures located in the midbrain. The substantia nigra is involved in the production of dopamine and plays a crucial role in movement control. It is primarily associated with Parkinson's disease, as the loss of dopamine-producing cells in this region leads to motor symptoms. The PAG is involved in pain modulation and is responsible for the body's response to pain. It also plays a role in the regulation of emotions and behaviors. Both the substantia nigra and PAG are important components of the midbrain.Rate this question:
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- 40.
The superior cerebellar peduncles send descending projections to
- A.
The spinal cord via the red nuclei and the rubrospinal tract
- B.
The spinal cord via the medial lemniscus
- C.
The spinal cord via the medial longitudinal fasciculus
- D.
The thalamus via the rubrospinal tract
- E.
The thalamus via the medial lemniscu
Correct Answer
A. The spinal cord via the red nuclei and the rubrospinal tractExplanation
The superior cerebellar peduncles send descending projections to the spinal cord via the red nuclei and the rubrospinal tract. These projections are involved in motor control and coordination. The red nuclei are involved in the control of voluntary movements, while the rubrospinal tract is responsible for the transmission of motor signals from the red nuclei to the spinal cord. Therefore, the correct answer is that the superior cerebellar peduncles send descending projections to the spinal cord via the red nuclei and the rubrospinal tract.Rate this question:
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- 41.
Pain and temperature information is conveyed via the brainstem by the
- A.
Corticospinal pathway which decussates in the medulla
- B.
Dorsal column-medial lemniscus pathway which decussates in the midbrain
- C.
Dorsal column-medial lemniscus pathway which decussates in the medulla
- D.
Spinothalamic tract which is laterally located throughout the length of the brainstem
- E.
Spinothalamic tract which decussates in the caudal medulla
Correct Answer
D. Spinothalamic tract which is laterally located throughout the length of the brainstemExplanation
The correct answer is the Spinothalamic tract which is laterally located throughout the length of the brainstem. This pathway is responsible for transmitting pain and temperature information from the body to the brain. Unlike the other pathways mentioned, the Spinothalamic tract does not decussate (cross over) in the medulla or midbrain. Instead, it remains on the same side of the body throughout the brainstem. This allows for the accurate relay of pain and temperature signals to the appropriate regions of the brain for processing and perception.Rate this question:
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- 42.
Neural signals mediating voluntary movement are carried by
- A.
Corticospinal pathway which decussates in the midbrain
- B.
Corticospinal pathway which decussates in the medulla
- C.
Dorsal column-medial lemniscus pathway which decussates in the midbrain
- D.
The pyramidal tract which decussates in the midbrain
- E.
The spinothalamic tract which is laterally located throughout the length of the brainstem
Correct Answer
B. Corticospinal pathway which decussates in the medullaExplanation
The correct answer is the corticospinal pathway which decussates in the medulla. This pathway carries neural signals for voluntary movement and the decussation (crossing over) of the pathway occurs in the medulla. This means that the signals originating from one side of the brain will control movement on the opposite side of the body. The midbrain, dorsal column-medial lemniscus pathway, pyramidal tract, and spinothalamic tract are not involved in the decussation of voluntary movement signals.Rate this question:
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- 43.
4. Left-side hemiparesis (muscle weakness) and paralysis of eye muscles is most likely due to a brainstem lesion in the
- A.
Right and left dorsal midbrain
- B.
Right dorsal midbrain
- C.
Left dorsal midbrain
- D.
Right ventral midbrain
- E.
Left ventral midbrain
Correct Answer
D. Right ventral midbrainExplanation
Left-side hemiparesis and paralysis of eye muscles suggest a lesion in the right side of the brainstem. The brainstem is responsible for controlling various functions, including motor control and eye movements. The ventral side of the brainstem is involved in motor function, while the dorsal side is involved in sensory function. Since the symptoms mentioned in the question are related to motor function, the lesion is most likely in the right ventral midbrain.Rate this question:
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- 44.
This sleep disorder is commonly seen in pregnancy, hemodialysis or peritoneal dialysis for renal failure and iron-deficiency anemia. Its relationship with iron metabolism abnormalities has led to studies indicating that this sleep disorder is associated with abnormal iron metabolism within the central nervous system:
- A.
Restless leg syndrome
- B.
Delayed sleep syndrome
- C.
Sleep terrors
- D.
Confusional arousal
- E.
REM sleep parasomnias
Correct Answer
A. Restless leg syndromeExplanation
Restless leg syndrome is commonly seen in pregnancy, hemodialysis or peritoneal dialysis for renal failure, and iron-deficiency anemia. Studies have shown that this sleep disorder is associated with abnormal iron metabolism within the central nervous system.Rate this question:
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- 45.
It appears that certain brain areas are particularly important for the emergence of awareness. For instance, cortical damage or disruption of the neural links to this brain area appears to be crucial to conscious awareness:
- A.
Pontine reticulospinal tract
- B.
Nucleus basalis of meynert
- C.
Thalamus
- D.
Hypothalamus
- E.
Locus coereulus
Correct Answer
C. ThalamusExplanation
The thalamus is a brain area that is crucial for conscious awareness. Damage or disruption to the neural links to the thalamus can lead to a loss of conscious awareness. This suggests that the thalamus plays a key role in the emergence of awareness.Rate this question:
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- 46.
A 6 month old male patient shows impaired mental ability and difficulty swallowing. After an examination, you suspect Farber’s disease. A molecular finding associated with Farber’s disease is
- A.
A decrease in sphingomyelinase activity and increased accumulation of sphingomyelin
- B.
An increase in ceramidase activity and increased accumulation of ceramide
- C.
A decrease in ceramidase activity and increased accumulation of ceramide
- D.
An increase in sphingomyleinase activity and decreased accumulation of sphingomyelin
- E.
An increase in ceramidase and sphingomyelinase activity
Correct Answer
C. A decrease in ceramidase activity and increased accumulation of ceramideExplanation
Farber's disease is a rare genetic disorder characterized by the accumulation of ceramide in various tissues. Ceramidase is the enzyme responsible for breaking down ceramide. A decrease in ceramidase activity would result in an increased accumulation of ceramide, which is consistent with the molecular finding associated with Farber's disease.Rate this question:
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- 47.
Decarboxylation of serine produces
- A.
Phosphatidylcholin
- B.
Phosphatidylethanolamin
- C.
Phosphatidylglycerol
- D.
Phosphatidic acid
- E.
Plasmalogen
Correct Answer
B. pHospHatidylethanolaminExplanation
Decarboxylation of serine produces phosphatidylethanolamine. Serine is an amino acid that can undergo decarboxylation, which involves the removal of a carboxyl group (-COOH). This process results in the formation of phosphatidylethanolamine, which is a type of phospholipid found in cell membranes. Phosphatidylethanolamine plays a crucial role in maintaining the integrity and fluidity of cell membranes, as well as participating in various cellular processes such as signaling and protein trafficking.Rate this question:
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- 48.
An ether linkage between a fatty acid and glycerol is typical of
- A.
Plasmalogen
- B.
Phosphatidic acid
- C.
Phosphatidylcholine
- D.
Cerebroside
- E.
Cardiolipin
Correct Answer
A. PlasmalogenExplanation
An ether linkage between a fatty acid and glycerol is typical of plasmalogen. Plasmalogens are a type of phospholipid that contain a vinyl ether bond at the sn-1 position of the glycerol backbone. This unique structure gives plasmalogens important biological functions, such as being involved in cell membrane structure and function, as well as serving as a precursor for the synthesis of other important molecules like platelet-activating factor.Rate this question:
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- 49.
A patient with medial medullary syndrome is likely to present with
- A.
Impaired motor function and impaired ocular control
- B.
Impaired motor control of limbs and impaired control of the tongue
- C.
Impaired ocular control and loss of pain sensation
- D.
Loss of pain sensation ipsilateral to the lesion
- E.
Impaired motor function and loss of temperature sensation
Correct Answer
B. Impaired motor control of limbs and impaired control of the tongueExplanation
A patient with medial medullary syndrome is likely to present with impaired motor control of limbs and impaired control of the tongue. This is because medial medullary syndrome is caused by damage to the medial part of the medulla oblongata, which is responsible for controlling motor function and coordination. The limbs may be weak or paralyzed, and the tongue may be affected, leading to difficulty in speaking and swallowing. Impaired ocular control and loss of pain sensation are not typically associated with medial medullary syndrome. Loss of pain sensation ipsilateral to the lesion and impaired motor function and loss of temperature sensation are more commonly seen in other conditions such as Brown-Séquard syndrome.Rate this question:
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- 50.
The structures included within the lentiform nucleus include
- A.
The striatum and globus pallidus
- B.
The caudate, putamen, and globus pallidus
- C.
The putamen and globus pallidus
- D.
The caudate and putamen
- E.
The globus pallidus and substantia nigra
Correct Answer
C. The putamen and globus pallidusExplanation
The lentiform nucleus is a structure located in the brain that is part of the basal ganglia. It is composed of the putamen and the globus pallidus. These two structures work together to regulate movement and motor control. The putamen receives input from the cortex and relays it to the globus pallidus, which then sends signals to other areas of the brain to coordinate movement. Therefore, the correct answer is "The putamen and globus pallidus."Rate this question:
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Feb 01, 2024Quiz Edited by
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Jan 18, 2012Quiz Created by
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