Development and teratology of the endocrine and nervous system Anna Mac Gillavry 3.5.2021 Pituitary gland •Ectoderm (Rathke’s pouch) •Neuroectoderm of ventral wall of diencephalon HypDevAni Craniopharyngeal canal Pharyngeal hypophysis Agenesis/hypoplasia - agenesis is incompatible with life; panhypopituitarism Duplication of the gland – very rare Ectopic posterior pituitary – pituitary dwarfism Craniopharyngiomas – usually lie above the sella; cause hydrocephalus, growth failure, diabetes insipidus, lose of peripheral vision Duplication of the pituitary gland associated with multiple blastogenesis defects: Duplication of the pituitary gland (DPG)-plus syndrome. Case report and review of literature - Surgical Neurology International Obsah obrázku text, zbraň Popis byl vytvořen automaticky Pediatric Craniopharyngioma: Background, Pathophysiology, Epidemiology (medscape.com) Epiphysis •thickening of caudal part of ependyma that does not contribute to development of choroid plexus at the roof of diencephalon •neuroectoderm - Pineal gland agenesis – mutations PAX6 (paired box gene 6) Cureus | Pineal Gland Agenesis: Review and Case Illustration Thyroid gland •endodermal proliferation of pharyngeal floor between tuberculum impar and copula • •obliterating ductus thyreoglossus •foramen caecum • •bilobed diverticulum •lobus pyramidalis • •C-cells -neural crest origin -ultimobranchial body of 5th pharyngeal pouch • Pyramidal lobe – in 50 % of population Congenital hypothyroidism (1/3000) Ectopic thyroid gland – in 90 % cases it is lingual thyroid gland; sublingual thyroid gland Thyroglossal duct cyst – clinically important to distinguish from ectopic thyroid gland! Thyroglossal fistula Obsah obrázku mapa Popis byl vytvořen automaticky T.W. Sadler, Langman´s medical embryology, 12th edition •glandulae parathyroideae superiores from endoderm of 4th pharyngeal pouch •glandulae parathyroideae inferiores from dorsal process of 3rd pharyngeal pouch -together with thymus descend to lower poles of thyroid • Embryonic development of parathyroid gland http://www.cambridgequestions.co.uk/diagrams/Development%20-%20Pharyngeal%20arches.png Ectopic parathyroid tissue – the inferior parathyroids are more variable in their position Supranumerary parathyroid glands https://embryology.med.unsw.edu.au/embryology/images/d/df/Week10_adrenal.jpg Cortex -mesoderm -mesothelium, coelomic epithelium •primitive fetal cortex 5-6th week -fetoplacental unit •definitive cortex -zona reticularis fully differentiates within 3 years - Medulla •neural crest - Suprarenal gland Week10 adrenal - Endocrine - Adrenal Development - Embryology (unsw.edu.au) Congenital adrenal hyperplasia – group of autosomal recessive disorders – excessive production of androgenes: causes rapid growth and accelerated sceletal maturation in both sexes Development of neural tube neural folds ectoderm neural groove spinal ganglion neural tube Closing of neural tube wall of amnion neural plate neural groove primitive pit primitive streak wall of amnion somites day 18 day 20 day 22 day 23 Development of spinal cord basal plate alar plate spinal ganglion ramus communicans sympathetic ganglion sulcus limitans sympathetic ganglion dorsal root ventral root developing mantle layer marginal myotom spinal nerve sympathetic neuroblasts germinal Development of brain mesencephalon rhombencephalon prosencephalon developing spinal cord eye cup developing heart nerves of pharyngeal arches diencephalon mesencephalon metencephalon myelenencephalon telencephalon Development of brain ventricles mesencephalon mesencephalon epiphysis hemispheres 3rd ventricle hypophysis floor of 4th ventricle lateral ventricle Neural tube defects (NTDs) -Spina bifida: spina bifida occulta – defect of vertebral arches covedr with skin and usually does not affect the neural tissue – 10 % of population; meningocele; meningomyelocele -Rachischisis -Hydrocephaly - Cranial defects -Holoprosencephaly (HPE) – 1 in 15000 (1 in 250 early miscarriage) -Schisencephaly -Meningocele, meningoencephalocele, meningohydroencepahlocele – 1 in 12000 -Exencephaly: anencephaly (=meroencaphaly – 2-4 times more common in female foetuses), craniorachischisis – polyhydramnios -Hydrocephaly – in most cases due to obstruction of the aqeduct of Sylvius (aqueductal stenosis) -Microcephaly The leading cause of intellectual disability is maternal alcohol abuse! -