Slight enlargement of ectodermal and endodermal cells at the cranial end?
Differentiation of 3 germ layers from which all tissues and organs develop?
Mesoderm arise from what cells?
Mesenchymal cells of the epiblast
Mesoderm develops in ____ week?
Embryonic origin of enamel?
Embryonic origin of the teeth except for enamel?
Mesenchymal cells arising from the primitive node which extends cranially to the prochordal plate?
Functions of the notochord? (2)
- Structural support
It acts as the main axial skeletal element of the early embryo.
Process of formation of neural plate and neural tube at the end of 3rd week?
Thickening of the ectoderm cranial to the primitive node?
Primordium of the CNS?
Cells found between the neural tube and ectoderm?
Neural crest cells
It makes up most of the connective tissues of the head?
Neural crest cells
Occurs when there is problem with migration of the neural crest cells?
Treacher Collins Syndrome
Symptoms of treacher collins syndrome? (4)
- Downward slanting eyes
- Small lower jaw
- Malformed or absent ears
- Prominent nose
Masses of mesoderm that lie on either side of the neural tube?
Primary brain vesicles? (3)
Folding of the embryo starts in the _____ week?
Primitive mouth of the embryo?
Combined ectoderm and endoderm with no intervening mesoderm?
It temporarily separates the stomodeum from the foregut?
Invagination of the stomodeal ectoderm which develops to form the anterior lobe of the hypophysis?
1st pharyngeal arch is also called?
Arch forming the facial muscles, vessels and hyoid bone?
2nd pharyngeal arch or hyoid arch
It become the future external acoustic meatus?
1st branchial/pharyngeal cleft
Structures that develop from the 1st pharyngeal pouch? (3)
- Middle ear
- Eustachian tube
Structure that develop from the 2nd pharyngeal pouch?
Structures that develop from the 3rd pharyngeal pouch? (2)
- Inferior parathyroid gland
- Thymus gland
Structure that develop from the 4th pharyngeal pouch?
Superior parathyroid gland