medical embryology - development of CNS

to what is the ventriuclar system (aka all brain ventricles) connected

the central canal of the spinal chord

what do the brain ventricles contain

cerebrospinal fluid

what structures are formed by the cephalic end of the neural tube (simultaneously with brain vesicle development)

2 flexures:

1. flexura cranialis

2. flexura cervicais (cervicle flexure)

when is the third flexure formed and what is the name and position

the flexura pontina is formed when the secondary brain vesicles are established and marks the boundary between meten en myelencephalon

what is the beginning of development of the CNS

it starts with neural plate induction form ectoderm stimulated by the primitive node

what seperates the mesen and metencephalon

the midbrain-hindbrain border, ookwle isthmus (=sharp bend)

during cytodifferentiation, neuroepethelial cells differentiate into:

neurblast cells (form neurons, glia cells & ependymall cells)

how are the mantle layer and marginal zone established

neurons migrate peripherally

describe the orientation of mantle and marginal zone

the central canal is surrounded by ependymal cells, surrounded by mantle zone, surrounded by marginal zone

what is the mantle zone, and what the marginal zone

1. mantle zone is the presumptive grey matter

2. marginal zone is the presumptive white matter

white matter always surrounds grey matter behalve in cerebral cortex

what is formed by the further divisions of mantle layer

the ventral and dorsal sides of neural tube thicken and form the dorsal alar plates (become sensory neurons) and the ventral basal plates (become motor neurons)

what sperates the two dorsal alar plates from e/o, what the two ventral basal plates. and what sperates the alar from basal plates

1. roof plate separates the dorsal alar plates

2. floor plate separates the ventral basal plates

The alar and basal plates are separated by the sulcus limitans

how are the lateral ventricles connected to the 3rd ventricle

Foramen of Mono = interventriculum foramen

the telencephalon can be divided into a ventral and dorsal region, what structures develop from each

1. the ventral region: subpallium = striatal rigde → corpus striatum → caudate nulecus & lentiform nucleus

2. dorsal region: pallium → hippocampus, cerebral cortex, commissures, olfactory bulbc & tracts

fill in: the ependymal wall only grows when its attached to … to form the ..

attached to the diencephalon roof plate to form the choroid fissure (waaruit choroid plexus ontstaan)

what are the two the surface structure of the cerebral cortec called

sulci (grooves) & convolutions (gyri)

what is the function of the olfactory tract

to connect the olfactory bulb to other brain sensory regions

Name of the groove that seperates sensory areas from motor ares

central sulcus

What type of plates does the diencephalon contain

roof plate, floor plate, 2 alar plates (no basal plates)

what seperates the diencephalon

the hypothalamic sulcus

what lies dorsal (above) the hypothalamic sulcus

thalamus (relays sensory and motor signals to the cortex) and and the epithalamus (includes pineal gland)

What lies ventral (above) the hypothalamic sulcus

hypothalamus, controls body temp, hormone release & hunger

describe formation of the hypophysis (pituitrary gland) in 4 steps

1. the Rathke’s pouch grows upward from the stomodeum (oral ectoderm) and the infundibulum grows as invagination of diencephalon

2. they meet

3. Rathke’s pouch loses its connection to the stomodeum and starts forming around the infundibulum

4. they fuse together to form the hypohysis (Rathkes pouch forms anterior, and infundibulum posterior)

shortly describe eye development (beschreven in 5 stappen)

1. optic vesicles form as invagination of lateral diencephalon

2. they invaginate to form the optic cup (gives rise to the neural retina and pigmented retina)

3. invagination of the surface extoderm forms the lens placode, this develops into the lens pit

4. lens pit pinches off and is now enclosed by the optic cup

5. posterior cells of lens vesicle elongate to form long primary fibers, these reach the les vesicle and form the lens.

As what structure do developing eyes first appear and how are optic cups connected to the 3rd ventricle

eyes first form as shallow grooves on side of fore brain called optic sulci

optic cups are connected to the 3rd ventricle through th eoptic stalk

what plates does the mesencephalon contain and what develops from them

1. dorsal alar plates (sensory tract) develop into tectum (2+2 colliculi)

2. ventral basal plates (motor tract) develops into tegmentum

What role does the mesencephalon play in connecting the cerebral cortex to the pons in the brainstem

the marginal layer of the mesencephalon enlarges and becomes the crus cerebri (cerebral peduncle) and this connect the pons and cerebral cortex

What does the metencephalon develop into

pons (ventral) & cerebellum

What does the myelencephalon develop into

medulla oblongata

Meten en Myelencephalon follow the fundamental pattern of alar and basal plates, but what is different about them

the expansion of the roof plate = ependymal roof plate (spans the fourth ventricle and is where the choroid plexus develops)

what are nuclei and how are they related to the meten/myelencephalon

nuclei are aggregations of cell bodies, the basal and alar plates are evntually organized into columns of nuclei, both visceral and somatic afferent (to the brain) and efferent (away from the brain)

What do the rhombic lips develop into and what is the function

Cerebellum, functions in coordinating sensory input wuth motor funcions (dus balans, posture, smoothness of movement)

what is the proces of neural plate formation called

neural induction