Nervous System Flashcards
Give the three primary and five secondary vesicles of the developing brain
Primary - Pro, Mes, and Rhomb (encephalon) comprising the forebrain, midbrain, and hindbrain. Secondary - Tel Di Mes Met Myel (encephalon)
Give the three primary and five secondary vesicles of the developing brain
Primary - Pro, Mes, and Rhomb (encephalon) comprising the forebrain, midbrain, and hindbrain. Secondary - Tel Di Mes Met Myel (encephalon)
Structures and cavities associated with the telencephalon in adults
Cerebral hemispheres, lateral ventricles
Structures and cavities associated with the diencephalon in adults
Thalami, third ventricle
Structures and cavities associated with the mesencephalon in adults
Midbrain, Aqueduct
Structures and cavities associated with the metencephalon in adults
Pons and Cerebellum, Upper part of fourth ventricle
Structures and cavities associated with the myelencephalon in adults
Medulla, lower part of fourth ventricle
What are the three flexures of the brain?
Cervical, Midbrain, and Pontine
The lumen of the spinal cord (central canal) is continuous with what brain structures?
The vesicles (lateral ventricles, third, fourth ventricles)
What are the two ends of the neural tube called and when does each close?
Anterior neuropore (25 days), Posterior neuropore (27 days)
Why is the early closing of the neural tube clinically significant?
The mother will not know she is pregnant, so she probably will not be taking folic acid, which greatly reduces risk of errors during neural tube closure
What are the two types of neural support cells, and of what developmental origin is each?
Macroglia (from neuroepithelium) and Microglia (from mesenchyme)
What is the original wall of the neural tube called, and what comes from here?
Neuroepithelial (ventricular zone) layer. Neurons and macroglia of the spinal cord come from here
What two areas for the gray and white matter of the spinal cord respectively?
The mantle zone (forms gray matter) and marginal zone (forms white matter)
What are the four thickenings of the developing spinal cord and what will each become?
Roof plate (Dorsal septum), Floor plate (Ventral median fissure), Alar plate (Dorsal horn), Basal plate (Ventral horn)
What divides the developing dorsal and ventral horns of the spinal cord, and how is it produced?
The sulcus limitans. Produced by differential thickening, allowing it to delineate the alar plate (future dorsal horn) and basal plate (future ventral horn)
Specify where neural crest cells come from, and name as many neural crest derivatives as you can
Edges of the neural folds. Derivatives - DRG, Sympathetic ganglia, Melanocytes, Chromaffin cells of adrenal gland, Ganglia of GI tract, Prevertebral ganglia
What type of cells are macroglia derived from and what are those cells derived from?
Glioblasts, which are derived from Neuroepithelial cells
What two cell types do macroglia give rise to and what does each of those types give rise to?
Astroblasts (Protoplasmic and Fibrous astrocytes), Oligodendroblasts (oligodendrocytes)
From what cell type do microglia arise?
Monocytes (from mesenchyme) cells of blood vessels as the CNS becomes vascularized
When do the primary brain vesicles (except the mesencephalon, which does not divide) divide to create the secondary brain vesicles?
During the 5th week
What is another name for the aqueduct, what can happen to it, and what is the condition associated with this?
Duct of Sylvius, it can become obstructed, this causes hydrocephalus
What does the pontine flexure do to the medulla and what is the effect on the developing plates?
It forces it to move laterally. This means the alar (sensory) plates will lie lateral to the basal (motor) plates
What is the most common etiology of congenital malformations involving the spinal cord stem?
Defective closure of the neural tube
