Embryology Flashcards
What is gastrulation
generation of 3 germ layers: endoderm, mesoderm and ectoderm
What is blastocyst
inner cell mass enveloped by outer layer
Where do neural crest cells migrate from
The neural tube
Where does the entire embryo come from?
Inner cell mass
source of embryonic stem cells
After fertilisation, cell division forms a ball of cells called ……… which begin to transcribe ……. ………….
morula
different genes
What does the primitive streak form?
site of gastrulation
What happens to the cells during gastrulation?
cells in epiblast moves towards primitive streak and leave
ingressing cells form mesoderm + endoderm
cells remaining form ectoderm
derivatives of ectoderm
Epidermis (skin)
nervous system
derivatives of mesoderm
skeletal muscle circulatory system blood kidney vertebral column
derivatives of endoderm
GI tract
gut/liver/lungs/thyroid
What are cells called that leave first and cells that leave last ?
rostral
caudal
The position along the ……….. ……… defines the ……… ……. axis of the ………
primitive streak
medial - lateral
mesoderm
The time when cells leave the streak defines their …….. along the ……… ……. axis
position
head-tail
Ectoderm forms the …….. …… which folds up into a …….
neural plate
tube
The midbrain and rhombomeres 1 + 2 contribute to the ……. and the …… …… arch
face
first branchial arch
The anterior part of the neural tube expands greatly as ……., ……… and ………..
forebrain
midbrain
hindbrain
Part of neural tube that forms hindbrain develops a series of 8 bulges the …….
rhomomeres
Lateral to the neural tube, the …….. partially segments to form 7 …….. and fully segments caudally to form ……
mesoderm
somatomeres
somites
neural crest cells give rise to ……… ……… that will undergo complex ……… to form a future face
facial ectomesenchyme
morphogenesis
Development of frontal prominence forms the …….
stomatodeum
Branchial arches consist of a ‘bar’ ………. tissue, lined on the outside by ……. and inside by …….
mesenchymal
ectoderm
endoderm
What are the branchial arches separated by on the outside and on the inside?
outside - deep clefts
inside - pouches
How many branchial arches are they?
5 arches numbered
1,2,3,4,6
NO 5th
Basic structure of each branchial arch
cartilage, nerve, artery
Basic structure of each pharyngeal arch
ectoderm
mesenchyme (neural crest + mesoderm)
endoderm
1st pharyngeal arch the two processes are:
maxillary and mandibular processes
Within the mandibular process is located the …….. …….. which will disappear with development and the …….. bone will form by ossification of the mesenchymal tissue
meckels cartilage
mandibular
Fundamental importance of 1st arch and nerve supply?
origin of two lower thirds of face
trigeminal
Second arch: Hyoid arch, the cartilage forms the ……, ……. process on the base of the skull. …….. horns and upper part of the ………. bone
stapes
styloid
lesser
hyoid
Second arch: function group of muscles of ……. ……
nerve supply:
facial expression
facial nerve
Third arch cartilage forms: greater ….. and the lower part of the ……. bone
horns
hyoid
muscle of 3rd arch and nerve supply
stylopharynegeus
glossopharyngeal
