Nervous System and Endocrine Glands MCQs

The ganglia of the autonomic nervous system are of neural crest origin. They are therefore ectodermal, as is the entire nervous system. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

The neural groove forms from the neural plate when lateral parts of the plate elevate to form neural folds. Neural folds are composed of neuroepithelium which gives rise to neuroblasts, gliablasts & ependymal cells. After the neural tube forms, it maintains contact with the amniotic cavity via cranial & caudal neuropores. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

The nerve supply travels with the muscle, indicating its origin and migration path. Rathke's pouch, from which the anterior pituitary is formed, is from oral ectoderm. Sulcus limitans divides motor and sensory areas. Sensory nuclei in the hindbrain lie dorsal to the motor nuclei. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

The hypophysis cerebri or pituitary gland develops from two sources i.e. surface ectoderm and neurectoderm. The adenohypophysis or anterior pituitary, develops from the surface ectoderm. An ectodermal diverticulum, called Rathke's pouch, grows upward from the roof of the stomatodeum (primitive mouth). This becomes the anterior lobe of the pituitary (pars distalis). Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 297

Spina bifida cystica and cranial meningoencephalocele arise due to a failure in bone development, not neural tube development. Neural tube defects, like rachischisis and anencephaly, result from failure of the neural folds to fuse during the 4th week. Bone surrounding the neural tube forms later than the CNS. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 288

Fiber tracts appear to become myelinated about the time that they start to function. Myelination is carried out centrally by oligodendroglia and peripherally by Schwann cells. Movements in the fetus usually begin toward the end of the third month, but are not readily felt by the mother until the 5th month. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

There are initially 3 brain vesicles: prosencephalon, mesencephalon & rhombencephalon. The pros- & rhombencephalon divide into 2 parts. The pontine flexure is opposite to the mesencephalic and cervical flexures. The marginal layer contains the nerve fibers arising from the neuroblasts. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

The sensory neurons lie in the alar plate. The neuroblasts are in the mantle area. The marginal layer contains the white, myelinated nerve fibers. The choroid plexus is in the roof plate. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 308