Endocrine - Adrenal Development
From Embryology
Adrenal
Lecture - Neural Crest Development | UNSW Embryology - Adrenal Development
- Richly vascularized - arterioles passing through cortex, capillaries from cortex to medulla, portal-like circulation
- Fetal Cortex - produces a steroid precursor (DEA), converted by placenta into estrogen
- Adult Medulla - produces adrenalin (epinephrine), noradrenaline (norepinephrine)
- Fetal adrenal hormones - influence lung maturation
Adrenal cortical hormones - (steroids) Cortisol, Aldosterone, Dehydroepiandrosterone
- zona glomerulosa - regulated by renin-angiotensin-aldosterone system controlled by the juxtaglomerular apparatus of the kidney.
- zona fasciculata - regulated by hypothalamo-pituitary axis with the release of CRH and ACTH respectively.
Adrenal medullary hormones - (amino acid derivatives) Epinephrine, Norepinephrine
Adrenal Development
- Fetal Adrenals - fetal cortex later replaced by adult cortex
- Week 6 - fetal cortex, from mesothelium adjacent to dorsal mesentery; Medulla, neural crest cells from adjacent sympathetic ganglia
- Adult cortex - mesothelium mesenchyme encloses fetal cortex
Adrenal Cortex
- Late Fetal Period - differentiates to form cortical zones
- Birth - zona glomerulosa, zona fasiculata present
- Year 3 - zona reticularis present
Endocrinology - Adrenal Cortex Development
Adrenal Medulla
- neural crest origin, migrate adjacent to coelomic cavity, initially uncapsulated and not surrounded by fetal cortex, cells have neuron-like morphology
- 2 cell types - secrete epinepherine (adrenaline) 80%; secrete norepinepherine (noradrenaline* 20%
