Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
What induces neural plate formation?
|
The notochord sends out neural signals (noggin, chordin, and follistatin) which block the suppressive signal from bone morphogenic protein (BMP-4). Without this inhibition the ectoderm forms epidermis (skin)
|
|
|
Describe the process of neurulation.
|
The process of formation of the neural plate and neural folds and closer of these folds to form the neural tube. The tube closes first in the middle then zippers out towards the ends. But the anterior neuropore (25 days) and the posterior neuropore close at different days. (23 days) The anterior end develops into the brain and the posterior end develops into the spinal cord
|
|
|
What is a neural tube defect?
|
Lack of closure of neural pores, either cranial or caudal
|
|
|
What does the prosencephalon give rise to?
|
telencephalon
diencephalon |
|
|
What does the rhombencephalon give rise to?
|
metencephalon
myelencephalon |
|
|
Describe the two phases of histogenesis and how the different cells arise.
|
1. Differentiation:
2. Maturation |
|
|
What do glioblasts give rise to and give 2 examples of this type of cell?
|
1. macroglia: astrocyes and oligodendrocytes
2. radial glial cells: ependymal cells and astrocytes |
|
|
The process of differentiation in histogensesis is guided by what 2 factors?
|
1. gene expression
2. growth factors |
|
|
From what does microglia derive from?
|
monocytes (mesenchymal cells) NOT glioblasts
|
|
|
What embryonic tissue layer are microglia from?
|
mesoderm
|
|
|
Describe the level of mitosis in the neural tube.
|
The cells closest to the inner part of the tube have the most mitotic characteristics but migrate towards the outside of the neural tube and lose their mitotic
|
|
|
What cells secrete cerebral spinal fluid (CSF)
|
ependymal cells
|
|
|
What cells signal to neurons?
|
astrocytes
|
|
|
What cell type provides myelination for neurons?
|
Oligodendrocytes
|
|
|
What are the 2 types of lineage from the Bipotential progenitor cell?
|
Glial or neuronal
|
|
|
what cells provide processes from the inner to outer neural tube that provides tracks for neurons to move on?
|
Radial glial cell
|
|
|
Describe the ventricular zone.
|
Also called the ependymal layer, highly mitotic epithelial cell region closest to the central canal which will become the ventricular system
|
|
|
Describe the subventricular zone.
|
Under the ventricular zone and it contains neuroblasts with mitotic properties
|
|
|
Describe the intermediate zone.
|
region contains differentiating post-mitotic neuroblasts. Lots a grey matter which is cell bodies (also called mantle layer)
|
|
|
Describe the cortical zone.
|
Contains post-mitotic cells that migrated from subventricular zone. Will become grey and white matter adjacent to the intermediate zone
|
|
|
What is the difference between the alar plate and basal plate?
|
The 2 regions are divided by the suclus limitans. The basal plate (ventral root) (anterior region) has motor components of spinal cord (efferent) and the alar plate has sensory regions (dorsal root) (afferent).
|
|
|
Describe the marginal zone.
|
Located furthest from the central canal and has few cells and mostly axons and dendrites (neuronal processes but not cell bodies)
|
|
|
During the 2 growth spurts, what are the infants most sensitive to and when?
|
1st growth spurt during the 10th and 18th wk babies brain is vulnerable to infection, irradiation, and chromosomal abnormalities. The 2nd growth spurt at 30th wk - 2 yrs baby's brain is vulnerable to malnutrition
|
|
|
What is the role of neurotrophins.
|
They inhibit apoptosis so it inhibits the natural pruning of neurons so that there are no redundant neurons
|
