Early Embryo development Flashcards
Connecting stalk
will form the umbilical cord attached to ventral side of embryo.
Dermis and subcutaneous layer of skin
Mesoderm
Bone/ligamenmt/tendon/cartilage
Mesoderm
Mesoderm membrane, expansion, & differentiation
extends beyond oropharyngeal membrane and found in the cardiogenic area near the heart primordium
Lateral plate mesoderm
Splanchnic - Organs CT, cardiovasculr and Somatic - Pleura
oropharyngeal membrane
future site of the mouth
Prechordal plate
where the ectoderm and endoderm fuse, will form oropharyngeal membrane
Lateral folding speed differences
Dorsal>ventral
cloacal membrane
future site of the anus
Cranial Caudal Folding pattern: Other (Head)
Septum transversum, perimoridal heart, pericardial coelom, and oropharyngeal membrane move to ventral surface.
Notochordal canal/(tube)
formed from the primitive pit extending into teh notochordal process.
Cranial Caudal Pattern: Tail Folding
extends over cloacl membrane,formation of the hindgut, connecting stalk and allantois
epithelium of lower anal canal, external auditory meatus
surface ectoderm
Lateral folding pattern: lateral folding
Ventrolateral wall fold toward median plane to create cylindrical embryo as spinal cord and somites rapidly grow. Form the midgut and reduce its connection to teh yolk sac via the omphaloenteric duct/vitelline tube
sacrococcygeal teratoma
Primitive streak does not disappear. Tumors contain tissues derived from all three germ layers in incomplete stages of differentiation.
Epidermis hair nails sweat
surface ectoderm
Muscles
Mesoderm
CNS
Neuroectoderm
Pericardioperitoneal canal
A temporary gap between the pericardial coelom and intraembryonic ceolem
Somites
sclerotome, dermatome, myotome
Cranial Caudal Folding pattern: Brain (Head)
Develops dorsally into amniotic sac and cranially into oropharyngeal membrane over developing heart.
Allantois
Once folded will connect to rudimental GI tract, will connecting to urachus, and form umbilical ligament, the extraembryonic mesoderm of allantois will form umbilical artery/vein
Lateral folding pattern: Somatic and splanchnic mesoderm
The somatic mesoderm and embryonic ectoderm will form the somatopleure (body wall) and the mesoderm and endoderm will form splanchnopleure (gut)
Cranial caudal speed folding differences
cranial>caudal>body
Another name for caudal dysplasia
Sirenomella
Gastrulation
forming the trilaminar embryonic disc.
Paraxial mesoderm
Head and somite
Midgut
formed from lateral folding in the endoderm to create teh small intestine.
Foregut
Formed during head folding of cranial caudal pattern from the endoderm. To eventually create pharynx, esophagus, and lower respiratory system.
Notochord functions
defines primordial longitudinal axis, provide signals fro axial musculoskeletal structures and CNS, contributes to nucleus pulposus
Notochordal plate
floor of notochordal process fuses with the underlying embryonic endoderm
Lateral folding pattern: coeiomic spaces
Intraembronyic coelum and extraembryonic coelom are temporarily connected until folding occurs
Caudal dysplasia
Abnormal gastruation, disturbed mesoderm migration – especially the fusion of the cloacal membrane.
Neurentic canal
notochord process fuses with embryonic endoderm, transitory communication between amnioitic and yok sac. Disappears when notochord is complete.
Septum transversum
Will form central tendon fo diaphragm lies caudal to the heart.
