Lecture 27 Flashcards
_______________: the process by which some of the ________ in the trilaminar embryo develops into the ______ _____, which will form all the neural tissue
- takes place during week ____
neurulation; ectoderm; neural tube
- 3
What germinal layer does the….develop from?
- neural tube= _________
- neural plate= ________
- notochord= _________
- ectoderm
- ectoderm
- mesoderm
_________: a hollow structure that forms during embryonic development from the neural plate, it eventually develops into the CNS
neural tube
The formation of the neural tube….
- the neural tube initially forms as a flat sheet of cells (the ______ ______) along the _______ surface of the embryo
- through a process called ________, the ____ _____ folds and fuses to create a tube-like structure
- neural plate; dorsal
- neuralation; neural plate
__________: chord-like structure that runs along the ________ side of the embryo and is the basis for the axial ___________
- it is a continuation of a specialized structure called the __________ _____
- it form thought a process called ________, because the cell migrate, and they organize themselves into a rod-shop
- runs longitudinally stretching form the ______ to the ______ end
notochord; dorsal; skeleton
- primitive node
- gastrulation
- head (rostral/cranial)
- tail (caudal)
In vertebrates the notochord eventually gets replaced by the ________ _____ during development, however remnants of the notochord persist in the centers of the ___________ discs
vertebral column; intervertebral
In terms of neural tube formation….
- the notochord secretes molecules that tell the overlying _________ to become the neural tube
- these signals instruct the _______ to thicken and transform into the _______ ______, which is the ______ step in neurulation
- ectoderm
- ectoderm; neural plate; first
Is the neural plate wider at the cranial or caudal end?
cranial, it eventually becomes the brain
Neural tube formation
- the notochord induces the lateral edges of the ectoderm to begin to form the _______ _____
- the resulting depressed mid-region from the formation of the neural folds is called the ______ _____
- the neural plate bends upward, it ends eventually meeting at the edges now knows as the _______ ______
- neural folds
- neural groove
- neural crest
- as the neural folds continue to rise and converge in the middle, they gradually fuse together, closing up like a zipper to form the _____ ______
- once the neural folds completely fuse, the _____ _____ is physically separated from the surface ectoderm by a layer of ______ _____ ____
- neural tube
- neural tube; neural crest cells
___________: arise from a specific region of the mesoderm which flanks the notochord
- these will eventually differentiate into various structures like the ____ _____, _________, and _______
somites
- skeletal muscle; vertebrae; dermis
The neural tube differentiates into major structs of the _____
- anterior (front end): develops into the ______ (_______,______,_______)
- posterior (back) portion: becomes the ______ ______
- lumen (central cavity): transforms into fluid-filled spaces like the _________ of the brain and the _____ ______ of the spinal cord
- CNS
- brain (forebrain, midbrain, hindbrain)
- spinal cord
- ventricles; central canal
Structures that neural crest cells differentiate into
1. Cells of the _______
2. ___________
3. __________ cells
4. ___________ such as _________
5. the two inner __________ (_________ and _________)
6. most of the __________ including nerves
1 . PNS
2. melanocytes
3. endocrine
4. mesenchymal; osteocytes
5. meninges (arachnoid; pia mater)
6. PNS
The embryonic brain develops complexity through enlargements of the _______ ________ called ________
neural tube; vesicles
Three primary brain vesicles
1.
2.
3.
- prosencephalon (forebrain)
- mesencephalon (midbrain)
- rhombencephalon (hindbrain)
