Neuroanatomy/embryology

The correct answer is Metencephalon because it includes the structures affected in the question: Fourth ventricle, Cerebellum, and pons. Diencephalon includes structures like thalamus and hypothalamus, Myelencephalon includes the medulla oblongata, and Telencephalon includes the cerebral cortex.

Neural tube defects are associated with increased levels of ACHETYLCHOLINEESTERASE and ALPHA FETO PROTEIN (AFP) in the amniotic fluid. These markers can aid in the prenatal diagnosis of NTDs due to a failure in fusion in anterior and posterior neuropores.

Congenital absence of pain perception is often associated with abnormalities in small-diameter neurons in the dorsal root ganglia, which are essential for transmitting pain signals.

In this scenario, the classic movement disorder known as hemiballismus is described. The symptoms suggest a lacunar infarct affecting the subthalamic nucleus of the opposite side, which leads to the characteristic flapping and jerky movements seen in hemiballismus.

The correct answer highlights the importance of understanding the vertebral levels from which sensory nerves originate in relation to dermatomes, rather than just memorizing the names of dermatomes. This approach tests both the memorization of dermatome locations and basic medical knowledge of spinal anatomy.

When analyzing the scenario described, the correct answer is the Oculomotor nerve which is responsible for the efferent pathway of pupillary constriction. The incorrect answers are the Optic nerve, Trochlear nerve, and Trigeminal nerve which are not directly associated with the efferent pathway for pupillary constriction.

The correct answer is 'sda' as it directly corresponds to the question.

The question describes symptoms associated with the involvement of the mandibular branch of the trigeminal nerve (CN V3) passing through the foramen ovale, leading to sensory and motor deficits in the innervated areas.

The correct answer refers to the termination point of secondary neurons of the spinothalamic tract, which is contralateral VPN nucleus of thalamus. Incorrect answers do not accurately describe the termination point of these specific neurons.

Uvula deviation occurs to the opposite side of a brainstem lesion due to the unopposed action of the intact side resulting in a deviation towards the affected side.

The correct spelling of the abbreviation 'asd' is 'asds'.

NOTOCHORD is that thing that induces the differentiation of ectoderm and notochord itself is derived from MESODERM. It is important to know that timing of this differentiation of ectoderm induced by notochord happens in the FIRST trimester of pregnancy during days 18-21.

The correct answer explains the role of SHH and Wnt in determining the dorsoventral axis based on their dorsal and ventral travel, respectively.

During development of the nervous system, the DORSAL Horn and DORSAL column sensory pathways precursors specifically arise from the ALAR Plate, a DORSAL structure.

The correct answer is BASAL plate-VENTRAL structure because development of VENTRAL horns and CORTICOspinal tracts is associated with the basal plate in the embryonic neural tube.

The correct answer is that the nucleus pulposus originates from the notochord, which is a derivative of mesoderm. The notochord is a crucial structure in early embryonic development and plays a role in the formation of the vertebral column.

The Hypoglossus nerve innervates the intrinsic muscles of the tongue, including the genioglossus, hyoglossus, and styloglossus muscles.

The third ventricle is a cavity located in the diencephalon, which is a part of the prosencephalon. The thalamus and hypothalamus also originate from the diencephalon.

The correct answer is that the 2 LATERAL ventricles and CEREBRAL HEMISPHERES are derived from the TELEncephalon of the PROSENCEPHALON. Other parts of the brain mentioned in the incorrect answers are not responsible for the formation of these structures.

The MESENCEPHALON is the structure that gives rise to the AQUEDUCT of sylvius as well as the MIDbrain and OPTIC VESICLE/CUP. The other structures mentioned in the incorrect answers are responsible for different functions in the brain.

The correct answer states that the METencephalon gives rise to the UPPER part of the fourth ventricle, PONS, and CEREBELLUM while the MYencephalon gives rise to the LOWER part of the fourth ventricle and MEDULLA. The incorrect answers provided have mixed up the vesicles and their associated structures, leading to incorrect pairings of structures with vesicles.

The main cells involved in reactive gliosis are glial cells known as ASTROCYTES, which are derived from NEUROepothelia (NEUROECTODERM).

Neural crest cells are a transient embryonic cell population that gives rise to various components of the peripheral nervous system, including neurons.

In anencephaly, the lack of a swallowing center due to the failure in closure of the rostral neuropore during development results in polyhydramnios. This condition is not caused by leakage of CNS from the open calvarium, excessive production of amniotic fluid by the fetus, or compression of the esophagus.

Maternal Type 1 Diabetes is a known risk factor for anencephaly due to its effects on fetal development.

This question aims to highlight the differences in presentation and underlying causes between meningocele and meningomyelocele, which are both types of neural tube defects.

Holoprosencephaly is caused by a defect in the separation of the prosencephalon during the 5-6th weeks of development leading to abnormalities like fused basal ganglia and a single lateral ventricle. The absence of falx cerebri in frontal ventricles is also a notable characteristic.

Neural tube defects occur due to malformation during embryonic development, rather than deformation later in life.