From which embryonic layer is the pituitary gland primarily derived?
Solution
Correct Answer: Option A
- The pituitary gland is primarily derived from the ectoderm, which is one of the three primary germ layers formed during embryonic development.
- Specifically, the anterior pituitary (adenohypophysis) originates from an upward invagination of the oral ectoderm known as Rathke's pouch.
- This pouch extends from the roof of the developing mouth (stomodeum) towards the brain.
- Meanwhile, the posterior pituitary (neurohypophysis) develops from an extension of the neuroectoderm of the diencephalon, a part of the brain.
- Both parts together make the pituitary gland a composite structure primarily derived from the ectodermal layer.
- It is important to note that the mesoderm gives rise to many other structures such as muscles, bones, and the cardiovascular system, but not the pituitary gland.
- Similarly, the endoderm forms the lining of internal organs like the gastrointestinal and respiratory tracts, and the neural crest cells contribute mainly to peripheral nervous system elements and some craniofacial structures, not the pituitary gland.
Thus, the correct answer is ectoderm, highlighting the crucial role of this germ layer in forming the pituitary gland.
Reference: Langman’s Medical Embryology, 14th Edition, Chapter 14: Development of the Nervous System and Special Senses, Page 185-187
- Specifically, the anterior pituitary (adenohypophysis) originates from an upward invagination of the oral ectoderm known as Rathke's pouch.
- This pouch extends from the roof of the developing mouth (stomodeum) towards the brain.
- Meanwhile, the posterior pituitary (neurohypophysis) develops from an extension of the neuroectoderm of the diencephalon, a part of the brain.
- Both parts together make the pituitary gland a composite structure primarily derived from the ectodermal layer.
- It is important to note that the mesoderm gives rise to many other structures such as muscles, bones, and the cardiovascular system, but not the pituitary gland.
- Similarly, the endoderm forms the lining of internal organs like the gastrointestinal and respiratory tracts, and the neural crest cells contribute mainly to peripheral nervous system elements and some craniofacial structures, not the pituitary gland.
Thus, the correct answer is ectoderm, highlighting the crucial role of this germ layer in forming the pituitary gland.
Reference: Langman’s Medical Embryology, 14th Edition, Chapter 14: Development of the Nervous System and Special Senses, Page 185-187
Practice More Questions on Our App!
Download our app for free and access thousands of MCQ questions with detailed solutions