BIOL 2410 Lecture Notes - Lecture 8: Ependyma, Neural Tube, Neural Crest
15 Nov 2016
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Lecture 8 – BIOL 2410
Outline
• CNS develops from a hollow tube
o Ventricles
o White matter and grey matter
• Support and protection for CNS
o Meninges
o Ventricles and cerebrospinal fluid (CSF)
o Blood brain barrier
• Neuroanatomy and function
CNS Development
• In the 20day embryo, neural plate cells migrate toward the midline, neural cells migrate with the
neural plate cells
o They fold in and form a tube
• By day 23 of embryonic development, neural tube formation is almost complete
o The neural crest is the PNS
o The neural tube is the CNS - the lumen
• Have Ependymal cells and neural stem cells
• A 4week human embryo showing the anterior end of the neural tube which has specialized into
three brain regions
o Forebrain, midbrain, and hindbrain - anterior
o Spinal cord - posterior
• At 6 weeks, the neural tube has differentiated into the brain regions present at birth. The central
cavity (lumen) will become the ventricles of the brain
o Forebrain becomes bigger, faster
• 11 weeks of embryonic development, the growth of the cerebrum, from forbrain, is noticeably
more rapid than that of the other divisions of the brain
• 40 weeks, at birth, the cerebrum has covered most of the other brain regions, its rapid growth
within the rigid confines of the cranium forces it to develop a convoluted furrowed surface
o We get folds in our brain because there is no more room in the cranium
Ventricles
• Ventricles - fluid filled cavities within the brain, remnants of the "hollow tube" from which the
brain is developed
o 4 ventricles in the brain - 2 lateral and 2 descending
• The 2 descending is in the middle of the brain and the other is connected with the
spinal cord
o Contains the CSF
• Central cavity - hollow tube in the spinal cord, continuous with the ventricles
• Both lined with Ependymal cells
Forebrain
Cerebrum
Cerebral hemispheres
Basal ganglia
Lateral and 3rd ventricles
Diencephalon
Thalamus
Hypothalamus
And 2 endocrine glands
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Document Summary
Outline: cns develops from a hollow tube, ventricles, white matter and grey matter. Support and protection for cns: meninges, ventricles and cerebrospinal fluid (csf, blood brain barrier, neuroanatomy and function. 1. protection: bone and connective tissue: 3 levels of protection - bone, meningeal, and ecf, brain is encased in bony skull, or cranium. Spinal cord runs through vertebra column: meninges lie between bone and tissues to stabilize neural tissues and protect from bruising - supply blood, dura mater - thickest, hardest, remove blood, arachnoid membrane - cobweb. Subarachnoid space contains cerebrospinal fluid(csf) secreted by choroid plexus: pia matter - thin, adherent - most inside layer, vessels blood to brain, extracellular fluid - csf and interstitial fluid and plasma. Interstitial fluid - inside pia matter: csf is in place of the plasma - found in ventricles and n the space between the pia matter and the arachnoid membrane.
