UNSW Embryology

A6:Interorbital ligament. Nose. uppereyelids. Cornea. Anteriorchamber. Lens. Vitreous body. Sensory retina. optic ventricle (artefact). Pigment epithelium. Conjunctivalsac. Primordium of lacrimal glands (near lateral fornix of conjunctival sac).

A7: Medial rectus m. Primordium of nasolacrimal ducts. Upper eyelid (lateral). Lower eyelid (medial).

B1: Optic nerve. Note extensive temporal region of retina. Primordium of nasolacrimal ducts.

B2: Medial and lateral rectus muscles. Pigment epithelium. Note relationship of eye to nasal capsule, sphenoid cartilage and trigeminal ganglion. Primordium of nasolacrimal ducts (cut obliquely).

B3: On left, note course of maxillary division of trigeminal in relation to position of eye (superior to this level).

B3: Rhombic lip (developing cerebellum). IVth ventricle. Trigeminal ganglion. Adenohypophysis. Sphenoid cartilage.

B4: Cochlear duct and temporal cartilage. Semicircular duct (ampulla on L). precartilage of auricle (pinna). malleus (medial, L). Incus (lateral, L).

B5: Extemal auditory meatus. Auricle. Incus (dorsal). Malleus (ventral). Tubotympanic recess (auditory rube). Tensor tympani m. (L). Utricle. Semicircular ducts. Intemal auditory meatus (R), containing vestibular and spiral ganglia. Endolymphatic sac (L). Note proximity of sac to choroid plexus of 4th ventricle.

B6: External auditory meatus. Primordium of tympanic membrane (L). Manubrium of malleus(L). Basal turn of cochlea duct (L). Endolymphatic sac (R). Common crus (R). Junction of utricle and saccule (R). Meckel's cartilage. Stapes (R). Auditory tube.

A6: Interorbital ligament. nasal septum. primitive olefactory epithelium

A7: Interorbital ligament. nasal septum. superior concha and meatus. primitive olefactory epithelium

B1:

B2: vomeronasal organs (dark spots) beside nasal septum

B3: nasolacrimal ducts

B4: tongue

B5: unfused palatale shelves either side of tongue. section through mandible (top of image).

Stage 22 Embryo (Human)

A1

A2

A3

A4

A5

A6

A7

B1

B2

B3

B4

B5

B6

B7

C1

C2

C3

C4

C5

C6

C7

D1

D2

D3

D4

D5

D6

D7

E1

E2

E3

E4

E5

E6

E7

F1

F2

F3

F4

F5

F6

F7

G1

G2

G3

G4

G5

G6

G7