Multifactorial Conditions Flashcards
EGA
Embryonic genome activation
ESSP
Embryonic stage-specific pattern
Week 1 abnormalities
Within oocyte or spermatozoa or as a result of combination of the zygote
Generally fail to develop through blastocyst stage
Week 1 abnormality that develops
Trisomy 21 (down syndrome)
Week 2 consists of
Conceptus, bastocyst differentiation, and X inactivation
HcG - when is it released and what does it do?
Human chorionic gonadotropin…released in response to implantation
Initiates materan lhormonal changes, stopping menstruation
Used as a detection ofrm odern pregnancy tests
Day 6-7 what happens?
Implantation commences
Adplantation
Begins with inital adhesion to uterine epithelium…blastocyst slows and rolls and aligns with ICM closest to epithelium and stops
Implantation and when it happens
Migrations of blastocyst into uterine epithelium…complete by day 9
Coagulation plug
Left where blastocyst entered uterine wall
Day 12
Normal implantation sites
Uterine wall superior, posterior, and lateral
Day 8-9 what happens
Differentiation
Differentiation summary
Outer trophoblast - syncitotrophoblast and cytotrophoblast
Embryobalst (ICM) - epiplast and hypoblast
State referred to as bilainar embryo
X-inactivation occurs on what day and how?
Day 9…presence in female embryos of two XX raises gene dosage…inactivated one of X chromosomes…
All progeny of cell with a particular X chromsome inactivated,
Will have same chromosome inactivated
Ectopic pregnancy
Abnormal implantation.
Implantation outside the uterus
Hydatidiform moles occur when______
Only coneptus trophonlast layers proliferate but not embryoblast
Hydatidiform moles…what happens and how to diagnose?
No embyro but tropho secrete hCG
Use US to see no embryo
Week 3
Early placentation
Gastrulation
Folding
Day 15-`16
Gastrulation
Gastrulation
Epiblast layer of totipotential cells makes endo,meso, and ectoderm
Primitive streak
Visible feature representing cell migration
Ectoderm becomes
Nervous system, epidermis, and neural crest deriv
Endo derm becomes
GI, rep, uro system and encodrine glands
Mesoderm becomes
Notochord, axial skeleton, cartilage, connect tissue, trunk muscles, heart, kidneys, and blood
What is notochord required for?
Patterning surrounding tissues via shh signal (sonic hedgehog)
Shh protein does what?
Binds to receptors initiating pathways involved in tissue differentiation and velopment
Roels of notochord in development
Mechanical - influences folding
Morphogenic - secreting shh to regulate development of surrounding tissues
Day 17
Neurogenesis…nerual groove and folds form
Day 21
MSK development/cardiogenesis Mesoderm
Day 20
Neural crest
VACTERL assocaition from
Mesoderm during early development
VACTERL acronym
Vertebrae Anus Cardiac Tracheoesophageal fistula Renal Limb (radial agenesis)
VACTERL diagnosis
3 or more anomalies
VACTERL Eitiology
Unknown but probably multifactorial
Vertebral anomalies
Hypoplastic vertebra (small)
Hemivertebra (only 1/2 formed)
Can lead to scoliosis
Anal abnormalities
Anal atresia/imperforate anus
No opening outside of body
Cardiac abnormalities
VSD, ASD, tetralogy of Fallot
Absence of murmur does NOT
Rule out congenital heart disease
Symptoms of TE fistula
Frothy,white bubbles Coughing or choking Vomiting Blue skin Difficulty breathing
SOmetimes paired with congenital heart disease
Renal abnormalities
Inoomplete formation…urologic abnormalities…one umbilical artery
Limb abnormalities
Hypoplastic thumb, polydactyly, syndactyly, radial aplasia
Severity of VACTERLs
Vertebral may not require immediate attention but TE, AA might
Vertebral might let you in on other potential anommalies
Age of mother and father effect
Older mother - more likely aneuploidy
Older father - more likely sporadic autosomal dominant mutation (achondroplasia)
Example of genetic malformation
Synpolydactyly
Example of environmental malformation
REtinoic acid
Disruptions are not
Inherited
Terology of Fallot symptoms
Overriding aorta, VSD, pulmonary stenosis
