Endocrine - Parathyroid Development
From Embryology
Parathyroid
Lecture - Head Development | UNSW Embryology - Parathyroid
- Parathyroid Hormone - Increase calcium ions [Ca2+], stimulates osteoclasts, increase Ca GIT absorption (opposite effect to calcitonin)
- Adult Calcium and Phosphate - Daily turnover in human with dietary intake of 1000 mg/day
- secreted by chief cells
Principal cells cords of cells
Parathyroid Development
- Endoderm - third and fourth pharyngeal pouches, could also have ectoderm and neural crest
- 3rd Pharyngeal Pouch - inferior parathyroid, initially descends with thymus
- 4th Pharyngeal Pouch - superior parathyroid
- Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation
- Fetal parathyroids - respond to calcium levels, fetal calcium levels higher than maternal