Semester 2 Week 2 Embryo - Neuroembryology
- 1.
The myelin sheaths surrounding cranial and spinal nerves are formed by which of the following cells?
- A.
Astrocytes
- B.
Schwann cells
- C.
Microglial cells
- D.
Neuroglial cells
- E.
Oligodendrocytes
Correct Answer
B. Schwann cellsExplanation
Schwann cells are responsible for forming the myelin sheaths surrounding cranial and spinal nerves. Myelin sheaths are important for insulating and protecting nerve fibers, allowing for faster and more efficient transmission of nerve impulses. Astrocytes, microglial cells, neuroglial cells, and oligodendrocytes are all types of glial cells, but they do not form myelin sheaths around cranial and spinal nerves.Rate this question:
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- 2.
The pons and cerebellum are derived from the walls of which structure?
- A.
Metencephalon
- B.
Telencephalon
- C.
Diencephalon
- D.
Mesencephalon
- E.
Myelencephalon
Correct Answer
A. MetencephalonExplanation
The pons and cerebellum are derived from the walls of the metencephalon. The metencephalon is one of the five primary vesicles of the developing brain and is responsible for the formation of various structures, including the pons and cerebellum. The pons is a part of the brainstem that plays a role in relaying signals between different parts of the brain, while the cerebellum is involved in motor control, coordination, and balance.Rate this question:
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- 3.
The nucleus of the fourth cranial nerve, an exclusively motor nerve, which exits from the dorsum of the brainstem and innervates a muscle that moves the eyeball, is derived from which embryonic location?
- A.
Alar plate of the metencephalon
- B.
Alar plate of the myelencephalon
- C.
Basal plate of the mesencephalon
- D.
Basal plate of the diencephalon
- E.
Intermediolateral position near the sulcus limitans of the rhombencephalon
Correct Answer
C. Basal plate of the mesencephalonExplanation
The correct answer is the basal plate of the mesencephalon. The fourth cranial nerve, also known as the trochlear nerve, is a motor nerve that controls the superior oblique muscle of the eyeball. During embryonic development, the nucleus of this nerve is derived from the basal plate of the mesencephalon, which is a region in the midbrain.Rate this question:
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- 4.
Which of the following is a derivative of the epaxial musculature?
- A.
Rectus femoris
- B.
Biceps brachii
- C.
Trapezius
- D.
Innermost intercostal
- E.
Rectus capitis posterior minor
Correct Answer
E. Rectus capitis posterior minorExplanation
The epaxial musculature refers to the muscles located on the dorsal side of the body, specifically the muscles that run along the vertebral column. The rectus capitis posterior minor is a small muscle located in the posterior neck region, which is part of the epaxial musculature. Therefore, it is a derivative of the epaxial musculature. The other options, such as the rectus femoris, biceps brachii, trapezius, and innermost intercostal, are not derivatives of the epaxial musculature.Rate this question:
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- 5.
Nerve tracts running through the caudal medulla develop ventral to the sulcus limitans and eventually form the pyramids. Based on the position of their embryological development, what is the functional association of the pyramids?
- A.
Somatic sensory
- B.
Visceral sensory
- C.
Special sensory
- D.
Motor
- E.
Sympathetic
Correct Answer
D. MotorExplanation
The pyramids are formed by nerve tracts running through the caudal medulla, which develop ventral to the sulcus limitans. This indicates that the functional association of the pyramids is motor.Rate this question:
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- 6.
DiGeorge Syndrome is a suite of congenital craniofacial malformations associated with immunological defects due to failure of the thymus gland to differentiate and calcium metabolic defects related to failed parathyroid gland development. What is the primary embryological cause of this syndrome?
- A.
Failure of development of Rathke's pouch
- B.
Lack of migration of ectoderm through the primitive streak
- C.
Lack of normal development and migration of neural crest cells
- D.
Failure of descent of the thyroid gland primordium
- E.
Lack of normal closure of the cervical sinus
Correct Answer
C. Lack of normal development and migration of neural crest cellsExplanation
The primary embryological cause of DiGeorge Syndrome is the lack of normal development and migration of neural crest cells. Neural crest cells are a group of cells that arise from the neural tube during embryonic development and migrate to various parts of the body, including the thymus gland, parathyroid glands, and facial structures. In DiGeorge Syndrome, there is a failure in the normal development and migration of these cells, leading to the craniofacial malformations, immunological defects, and calcium metabolic defects associated with the syndrome.Rate this question:
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- 7.
Failure of closure of the cranial neuropore causes which serious congenital malformation?
- A.
Meroanencephaly
- B.
Rachischisis
- C.
Myelocele
- D.
Spina bifida occulta
- E.
Spina bifida cystica
Correct Answer
A. MeroanencephalyExplanation
Meroanencephaly is a serious congenital malformation that occurs when the cranial neuropore fails to close properly. This results in incomplete development and closure of the brain and skull. It is a severe form of neural tube defect that leads to significant brain abnormalities and is often fatal.Rate this question:
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- 8.
A young child is diagnosed with a communicating or non obstructive hydrocephalus. Which of the following is the most 14(01 cause of this condition?
- A.
Blockage of the foramen of Monroe
- B.
Blockage of the aqueduct of sylvius
- C.
Blockage of the foramen of Megendie in 4th ventricle
- D.
Blockage of the arachnoid villi
Correct Answer
D. Blockage of the arachnoid villiExplanation
Blockage of the arachnoid villi is the most common cause of communicating or non-obstructive hydrocephalus. The arachnoid villi are responsible for absorbing cerebrospinal fluid (CSF) and maintaining the balance of fluid in the brain. When these villi become blocked, the CSF cannot be properly absorbed, leading to an accumulation of fluid and subsequent hydrocephalus. This condition is often seen in young children and can result in symptoms such as enlarged head size, developmental delays, and neurological problems.Rate this question:
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Mar 22, 2023Quiz Edited by
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Jan 15, 2012Quiz Created by
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