1. The neural retina is derived from the (A) alar plate (B) choroid (C) neural crest (D) neural tube (E) telencephalic vesicle wall
1–D. The retina is derived from the neural tube, which gives rise to the entire CNS.
2. At birth, the conus medullaris is found at which vertebral level? (A) VT12 (B) VL1 (C) VL3 (D) VS1
2–C. At birth, the conus medullaris extends to VL3, and in the adult it extends to the VL1–VL2 interspace. At 8 weeks, the spinal cord extends the entire length of the vertebral canal.
3. Caudal herniation of the cerebellar tonsils and medulla through the foramen magnum is called (A) Dandy-Walker syndrome (B) Down syndrome (C) Arnold-Chiari syndrome (D) cranium bifidum (E) myeloschisis
3–C. Arnold-Chiari syndrome is a cerebello medullary malformation in which the inferior vermis and medulla herniate through the foramen magnum, resulting in communicating hydro cephalus.Arnold-Chiari syndrome is frequently associated with spina bifida.
4. A newborn has multiple congenital defects due to dysgenesis of the neural crest. Which of the following cells is most likely to be spared? (A) Dorsal root ganglion cells (B) Geniculate ganglion cells (C) Melanocytes (D) Motor neurons (E) Parafollicular cells
4–D. Motor neurons develop from the neural tube, more specifically from the basal plate. The other options are derivatives of the neural crest.
5–C. The corticospinal tract (pyramid) has its origin in the neocortex of the telencephalon.
6–A. The tela choroidea gives rise to the choroid plexus.
7–B. The inferior olivary nucleus is derived from the alar plate of the developing medulla.
8–D. The basal plate gives rise to the hypoglossal nucleus.
9–E. The alar plate gives rise to the solitary nucleus.
10–B. The GSE column innervates the lateral rectus muscle.
11–E. The GVE column gives rise to the superior salivatory nucleus of CN VII. This parasympathetic nucleus innervates the lacrimal, the sublingual, and the submandibular glands and also the palatine and nasal glands.
12–A. The cerebellum is derived from the alar plate. The alar plate gives rise to the rhombic lip, which becomes the cerebellum.
13–C. The pontine nuclei are derived from the alar plate.
14–D. The SVE column gives rise to motor neurons that migrate into the lateral pontine tegmentum and become the facial nucleus, CN VII.