Embryology (1st year)

1. DEVELOPMENT OF CNS

11. DEVELOPMENT OF ADRENAL GLAND

12. EYE BALL

13. • Retina is formed from optic vesicle, an
outgrowth of prosencephalon. The optic
vesicle is converted into optic cup.
• Lens derived from a thickened area of surface
ectoderm, the lens placode. The placode is
converted into lens vesicle which comes to lie
in the optic cup.

17. DEVELOPMENT OF EYE

27. EAR

28. INTERNAL EAR

32. • MIDDLE EAR
- epi. Lining of middle ear & auditory tube: from
tubo-tympanic recess.
- Malleous & Incus- meckel’s cartilage.
- Stapes- 2nd pharyngeal arch.
- Tensor tympani- 1st pharyngeal arch.
- Stapedius- 2nd pharyngeal arch.

37. • EXTERNAL EAR
- External Acoustic meatus: dorsal part of 1st
ectodermal cleft.
- Auricle/Pinna: 6 mesodermal
thicknings(hillock) of 1st & 2nd arch.
- Tympanic membrane: by apposition of tubo-
tympanic recess & 1st cleft.