Head and Neck Embryology

neurulation day 25

neural fold begins to fuse into a tube at the cranial end

neurulation day 27

neural folding reaches the caudal end, neural tube fully formed

neurodevelopment day 28

visible forebrain, midbrain, and hindbrain

forebrain secondary vesicles

telencephalon, diencephalon

midbrain secondary vesicle

mesencephalon

hindbrain secondary vesicles

metencephalon, myelencephalon

cerebral hemispheres embryonic origin

originates from telencephalon

thalamus embryonic origin

originates from diencephalon

midbrain embryonic origin

originates from mesencephalon

pons and cerebellum embryonic origin

originates from metencephalon

medulla embryonic origin

originates from myelencephalon

division of sclerotome

sclerotome divides into a cranial half and a caudal half

centrum formation

cranial half of one sclerotomes fuses with the caudal half of another sclerotome

neurodevelopment day 26

notochord is fully developed

intervertebral disc origin

originates from notochord in between centrums

notochord origin

chordamesoderm

neurodevelopment day 28

formation of cartilaginous centrums

neural arches

structures that grow from the centrum and protect the spinal cord

neuroblast

cell that develops into a neuron

origin of preganglionic sympathetic neurons

intermediate horn of grey matter of the developing spinal cord from T1 to L2

week 14 neurodevelopment

myelination begins

spinal nerve

place where anterior and posterior roots merge

sympathetic chain ganglia

a chain of clustered neuronal cell bodies originating from neural crest cells that runs down the thorax

neural crest cell derivative structures

postganglionic ANS neurons, sensory neurons, schwann cells