bilaminar embryonic disc dorsal and ventraldorsal→epiblast
ventral→hypoblast embryology HirotoShishido
Meckel diverticulum characteristicsrules of 2s
2 inches long(about 5cm)
2 feet (61cm) proximal to the ileocecal valve
occurs 2% of the population
2:1=male:female
often occurs 2 years of age(60%)
contain 2 types of epithelium(gastric,pancreatic) gastrointestinalembryology HirotoShishido
thyroid
embryologythyroid arises from floor of primitive pharynx and descends into neck through thyroglossal duct embryologyendocrinology HirotoShishido
What is pituitary gland derived from?anterior(adenohypophysis)→ectoderm(Rathke pouch)
how the splitting timing affect the type of identical twinsDD→split occurs within 2,3days following the fertization
MD→3〜8days
DD→8〜13days reproductiveembryologyOBGY HirotoShishido
muscular system development
which muscle does the tissue in abaxial domain and primaxial domain develop into respectivelyprimaxial ←from somites
→back,shoulder and intercoastal muscles
the most common type of tracheoesophageal anomaliesesophageal atresia(EA)with distal tracheoesophageal fistula(TEF) is the most common(85%) gastrointestinalembryology HirotoShishido
urachus and malignancyyolk sac forms the allantois(尿膜)
→allantoins become the urachus(尿膜管)(duct between bladder and umbilicus)
→urachus which fails to involute may increase the risk of infection,malignancy(eg,adenocarcinoma) embryology HirotoShishido
