File:Stage13 otocyst.jpg: Difference between revisions

Week 5 - Otocyst

Stage 13 embryo (week 5) showing otocyst that will form the inner ear.

left Ventrolateral view of the whole embryo with 5-mm scale bar. At this stage of development no middle or external ear structures are apparent and will be derived later from pharyngeal arches one and two (labeled). The gray bar through the head indicates the plane of cross-section (right).

right A cross-section of the head showing the size and position of the otic vesicles. At this stage of development they lie within the head mesenchyme behind pharyngeal arch one and two and in close apposition to the developing hindbrain. Note the close position of the otic vesicle to the rhombomeres, hindbrain folds that represent the initial segmentation of the hindbrain. Also shown are developing cranial ganglia and blood vessel lying adjacent to the otic vesicles. The wall of the otic vesicle at this stage is a simple epithelium.

Links: Inner Ear Development | Carnegie stage 13

Image Source: UNSW Embryology