BMS11004 - WEEK 5 TUESDAY Flashcards
neural plate, neurulation, differentiation, forebrain midbrain & hindbrain, cerebellum
what is neural place
small patch of ectodermal tissue on dorsal surface of developing embryo, known as “embryonic stem cells”
what 3 layers does gastrulation form?
endoderm (“gastrula, lining of viscera)
mesoderm (bones, muscles, connective tissue)
ectoderm (skin and nervous stem, form neural plate)
how many days at which are neural plate formed
17 days
at how many days is neurulation occur
22days
briefly explain neurulation
- neuroectoderm forms (ectoderm anterior to primitive streak thicken)
- becomes neural plate
- neural groove and folds due to uneven cell divisions
- form neural tube (CNS) and neural crest (PNS)
- neural tube later become ventricular system
what is a somite
part of mesoderm that becomes vertebrae and associated muscles (innervated by somatic motor nerves)
what neuron could potentially form neural crest
sensory, dorsal root ganglia neurons
neurons of PNS
why are women advised to take folic acid during conception and pregnancy
failure to close neural tubes causes anencephaly (unclosed at top, undeveloped forebrain), spina bifida (bottom not fully closed)
reduce risk of neural tube defects by 90% via influencing DNA synthesis
what is differentiation
neural tube cells start proliferating, moving and differentiating
rostral cells undergo more differentiation to become forebrain
outline process of differentiation from neural tube, to brain structure
- neural tube form 3 brain vesicles (prosencephalon “forebrain”, mesencephalon “midbrain”, rhombencephalon “hindbrain”)
- forebrain secondary differentiation into telencephalic vesicles (become telencephalon), diencephalon, optic vesicles (becomes optic stalk/nerve)
does the prosencephalon become forebrain, midbrain or hindbrain
forebrain
does the mesencephalon become forebrain, midbrain or hindbrain
midbrain
does the rhombencephalon become forebrain, midbrain or hindbrain
hindbrain
what does telencephalon differentiate into
cerebral cortex (thin layer with many neuron, connected via corpus callosum) and basal telencephalon (eg: amygdala, basal ganglia)
whats structure for cerebral cortex
grey matter, convoluted, large furrows (fissures), small fissure (sulci), gyri (ridge inbetween)
what 2 main structures does diencephalon differentiate into (and 1 other, less important structure)
thalamus and hypothalamus
SCN (suprachiasmatic nucleus)- circadian 24hr rhythms
what does thalamus do (a part of diencephalon)
inner chamber, divide into different nuclei
eg: sensory relay, transmits info from receptor to cortex
what does hypothalamus do (part of diencephalon)
autonomic and glandular 4F
what is cortical white matter?
white matter thats coming to/from cortex
what is corpus callosum?
huge white matter tract connecting both hemispheres
what does midbrain differentiate into
tectum (dorsal midbrain), tegmentum (ventral midbrain)
what does tectum include
inferior auditory colliculi, superior visual colliculi (REM saccade)
what does tegmentum divide up into
periaqueductal grey, RN, substantia nigra
what does periaqueductal grey do (tegmentum midbrain)
species specific behaiviour and lordosis, control pain
