Endo: Embryology

Question 1

All endocrine glands contain a ____dermal component

Answer 1

All endocrine glands contain a mesodermal component

*Because vasculature is derived from mesoderm

Question 2

Describe the origin of the four different parts of the pituitary gland

Answer 2

• Posterior pituitary: derived from neuroectoderm
  
  • Pars nervosa
• Anterior pituitary: derived from Rathke’s pouch, part of oral ectoderm
  
  • Pars distalis, pars tuberalis, pars intermedia

Question 3

What parts of the pituitary are derived from ectoderm?

Answer 3

ALL of them!

Anterior pituitary is oral ectoderm (Rathke’s pouch)

Posterior pituitary is neuroectoderm

Question 4

The adrenal cortex is ________ origin

The adrenal medulla is _________ origin

Answer 4

The adrenal cortex is mesoderm origin

The adrenal medulla is neural crest (ectoderm) origin

Question 5

In the formation of the adrenal cortex,

• _____________ start at urogenital ridge
• They then migrate _________ in two waves
• First wave of cells creates the ________
• Second wave of cells creates __________________

Answer 5

• Mesodermal mesothelial cells start at urogenital ridge
• They then migrate dorsally in two waves
• First wave of cells creates the Reticularis
• Second wave of cells creates the Glomerulosa and Fasiculata

Question 6

In the formation of the adrenal medulla,

• _________ cells migrate ventrally
• Cells now called _____________
• Cells continue migrating ventrally into early cortex
• Now called ______________
• These are the progenitors for medullary cells

Answer 6

• Neural crest cells (ectoderm) migrate ventrally
• Cells now called sympathogonia
• Cells continue migrating ventrally into early cortex
• Now called chromaffin cells
• These are the progenitors for medullary cells

Question 7

Name the origin of

• Thyroid follice cells:
• Calcitonin secreting cells:
• Vasculature:
• Parathyroid glands

Answer 7

• Thyroid follice cells: endoderm
• Calcitonin secreting cells: neural crest (ectoderm)
• Vasculature: mesoderm
• Parathyroid glands: endoderm

Question 8

• The thyroid follicular cells begin as the , an outpouching of the
• It stretches downwards as the
• Once below the ______, the __________ then degenerates

Answer 8

• The thyroid follicular cells begin as the thyroid diverticulum, an outpouching of the primitive gut endoderm
• It stretches downwards as the thyroglossal duct
• Once below the larynx, the thyroglossal duct then degenerates

Question 9

• The parathyroid begins as __________ nodules below the ________ pharyngeal pouches

Answer 9

• The parathyroid begins as endodermal nodules below the 3rd and 4th pharyngeal pouches

Question 10

The calcitonin secreting cells begin as the _____________ beneath the ____ pharyngeal pouches

They are _________ origin

Answer 10

The calcitonin secreting cells begin as the ultimobranchial body beneath the 4th pharyngeal pouches

They are neural crest origin

Question 11

What is the origin of thyroid follicular cells?

Thyroid C cells?

Answer 11

Thyroid follicular cells are from endoderm

Thyroid C cells are neural crest (ectoderm)