Lecture 16 (Exam 2) Flashcards
The early neural epithelium is made of what type of epithelial cells?
Simple cuboidal
The neural plate is made up of what type of epithelial cells?
Simple columnar epithelium
The early neural tube wall is made up of __________ epithelium. This means it has a single layer of columnar cells with nuclei at varying heights.
Pseudostratified
The early neural tube wall has limiting membranes. The external limiting membrane is the ______ ______.
Basal lamina
The late neural tube is made up of _________ epithelium.
Stratified
Nuclei within the neural epithelium move from a position next to the _______ to a position next to the external limiting membrane. _______ occurs close to the lumen, while ______ ______ occurs close to the external limiting membrane.
Lumen
Mitosis
DNA replication
In the neural tube, if the metaphase plate of neural epithelial cells is (PERPENDICULAR/PARALLEL) to the inner margin of the neural tube (next to lumen), two resulting daughter cells will remain proliferative.
Perpendicular
In the neural tube, if the metaphase plate of neural epithelial cells is (PERPENDICULAR/PARALLEL) to the inner margin, daughter cells closest to the lumen will remain proliferative and daughter cells further from the lumen will become a neuroblast.
Parallel
In the daughter cells from a parallel metaphase plate that are farther from the lumen, they will express ______ receptor then become postmitotic. After this, they will move to the external limiting membrane and become a neuroblast (pre-neuron).
Notch
In the embryo spinal cord cross-section, the ependymal zone is also known as the ________ zone. The mantle layer is also known as the ________ zone.
Ventricular
Intermediate
In ventral signaling, the notochord induces formation of the floor plate of the neural tube via ________.
Shh (Sonic hedgehog)
Shh (Sonic hedgehog) produced by the floor plate induces the formation of ______ ______.
Motor neurons
In dorsal signaling, ectoderm flanking the neural plates uses ______ to induce ______ in the future neural crest and later to maintain ______ and ______ to create a dorsalizing effect.
BMPs
snail-2
Pax-3
Pax-7
In dorsal signaling, expression of Pax-3 and Pax-7 is suppressed by _______ from the floor plate to suppress the dorsalizing effect in the basal plate.
Shh
In dorsal signaling, expression of Pax-3 and Pax-7 is suppressed by _______ from the floor plate to suppress the dorsalizing effect in the basal plate.
Shh
In mammals, the primitive node and the notochordal process act as the primary inductors of the ________ system.
Nervous
The cranial end of the neural tube divides into a ________ brain.
Tripartite
The caudal part of the early brain becomes subdivided into segments (neuromeres), of which the _________ are most prominent.
Rhombomeres
Specific ________ genes are expressed in a regular order in the rhombomeres.
Homeobox
The isthmic organizer (a signaling center) is located at the junction between the midbrain and the hindbrain and acts by the production of ______ anteriorly and ______ posteriorly.
Wnt-1
FGF-8
Most cranial ______ are associated with the caudal end of the brain.
Nerves
Most structures supplied by the cranial nerves are derived from the ________ ________.
Pharyngeal arches
Cranial Nerve _____ (rhombomere 2 in birds) innervates structures derived from the first pharyngeal arch. The progeny of a single neuroblast remain within rhombomere 2. Axons of rhombomere ____ join those of rhombomere 2.
V
3
Cranial Nerve _____ (rhombomere 4 in birds) innervates structures derived from the second pharyngeal arch. The progeny of a single neuroblast remain within rhombomere 4. Axons of rhombomere ____ join those of rhombomere 4.
VII
5
