Embryology Flashcards
Embryology Introduction
Twins (Mono, Di, Conjoined)
Mono: 1 oocyte
Di: 2 oocyte/ 2 sperm
Conjoined: Inner cells never seperate
Embryology of Nerves and Muscle
Dermatome
Dermis of the back
Development of Back
Wnt Pthwy
Transcription Factor
Ventral - Dorsal
Development of Back
Phocomelia
Absent of long bones, hand and feet w/trunk
Development of Back
ZPA
SHH
Anterior - posterior
Embryology Introduction
Embryology Week 1-2
Zygote –> Cleavage (2-16) –> Morula –> Blastocyte (32) –> Implantation in lining of the uterus
Embryology Introduction
Pharyngeal Arches
Forms Head & Neck
NC cells around foregut
6 –> 5 arches
Development of Back
Paraxial - Somatic
Appendicular Skeleton + skin outside back
Development of Back
Polydactyly
Many digits
Embryology Introduction
Embryology Week 9-38
Fetal Growth
Embryology Introduction
Embryoblast
Inner Cells
Epiblast (amniotic)
Hypoblast (Yolk Sac)
Embryo Proper
Embryology Introduction
Umbilical Cord
Allantois (waste), connecting stalk, vitelline duct
Development of Back
PCD in limbs
AER leads to apoptosis to remove webbing + smaller AER
Development of Back
Paraxial - Sclerotome
Surrounds NT cells + Notochord –> spinal cord formation
Annulus Fibrosus
Embryology Introduction
Mesoderm
Paraxial (Somite –> Sclero/Myo/Derma)
Intermediate (Urogential Organs - kidney/ureter)
Lateral (Somatic, Splanhic)
Development of Back
Amniotic Bands
Amputation of limbs
Development of Back
Brachydactyly
Shortened limbs
Embryology Introduction
Embryology Week 3-8
Gastrulation (bi –> trilameter), Neurulation (forming of neural cord),
Embryology of Muscle and Nerves
Sclerotome
most of the axial skeleton, split into cranial and caudal portion and form with the one above so the sensory portions can go through this layer to get to dermatome and myotome
Embryology Introduction
Ectoderm
Surface (skin/appendgies)
Neuro (Crest - PNS, Tube - CNS)
Development of Back
Cleft Floot
Extreme of syndactyly
Embryology Introduction
Zona Pellucida
Attracts sperm + prevents ectopic pregnancy
Development of Back
Paraxial - Notochord
Nucleus Pulposis
Development of Back
AER
FGF8 (limb growth)
proximal-distal
Embryology Introduction
Primitive Streak
Linear band of thick epiblast on caudal end (growing cranially) forming the primitive knot
Embryology Introduction
Trophoblast
Outer Cells
Cytotrophoblast (Embryo in uterus)
SyncytioTrophoblast (>2 Cyto)
Placenta
Embryology Introduction
Endoderm
GI Tract lining, urinary respiratory
Development of Back
Syndactyly
Fused Digits
Development of Back
Duplicated AER
2 AER
Embryology Introduction
Teratoma
Contains immature or fully formed tissues - hair/teeth
Embryology of Nerves and Muscles
Myotome
Skeletal Muscle
Epimere - intrinsic
Hypomere - trunk and limb
preaxial (flexors anterior)
Postaxial (extensor posterior)
Development of Back
Paraxial - Ventral/Hypaxial
Skeletal musculature of the ventrolateral wall and limbs
Development of Back
Club Foot
Walking on ankles
Insufficient amniotic fluid (oligohydramnios)
Embryology Introduction
Sacrococcygeal Teratoma
High pluripotent epiblast cells of primitive streak
Development of Back
Paraxial - Dorsal/epaxial
Intrinsic Back
Development of Back
Resegmentation
Intersegmental Vertebrae
Embryology Introduction
Amniotic Cavity w/Definitive Yolk Sac in folded embryo
Definitive yolk sac pushes away primary yolk sac
Development of Back
Amelia
Missing Limbs
