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)
Five secondary brain vesicles
1.
2.
3.
4.
5.
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
- Which brain vesicles does the cerebrum originate?
- Which brain vesicles does the thalamus originate?
- Which brain vesicles does midbrain the originate?
- primary= prosencephalon; secondary= telencephalon
- primary= prosencephalon; secondary= diencephalon
- primary= mesencephalon; secondary= mesencephalon
- Which brain vesicles does the pons originate?
- Which brain vesicles does the cerebellum originate?
BOTH
- primary= rhombencephalon; secondary= metencephalon
Which brain vesicles does the medulla oblongata originate?
primary= rhombencephalon; secondary= mylencephalon
Which two secondary vesicles are derived from the primary vesicle prosencephalon?
telencephalon and diencephalon
Which two secondary vesicles are derived from the primary vesicle rhombenceplahon?
metencephalon and myelencephalon
Embryonic folding occurs in week ____
- the result of embryonic folding is a dramatic transformation of the embryo from a flat disc of cells into a more complex, 3D structure with defined ______ and the beginning of recognizable _____
4
- axes; organs
What tissues, organs, and/or organ system arise from the endoderm? (within)
- lining of digestive tract
- liver, pancreas
What tissues, organs, and/or organ system arise from the mesoderm? (middle)
- circulatory system
- skeletal system
- muscular system
