1. BIO 240 HISTOLOGY REVIEW Eye and Ear Tissue Dr. Tim Ballard Department of Biology and Marine Biology

2. The dashed lines indicate the locations of the suspensory ligaments connecting the ciliary processes to the capsule around the perimeter of the lens. Structures of the eye Eyeball (anterior) – section – H&E – 4x objective cornea ciliary processes anterior chamber lens posterior chamber posterior cavity ciliary body conjunctiva iris

3. The dashed line indicates the location of the pupil, located between the anterior-most margins of the iris. Structures of the eye Eyeball (anterior) – section – H&E – 4x objective cornea anterior chamber lens conjunctiva iris pupil

4. The brown-black pigments of the choroid are melanin granules. Go back to the previous two slides and follow this pigment into the iris. Structures of the eye Eyeball (posterior) – section – H&E – 10x objective choroid posterior cavity retina sclera

5. Plexiform layers are areas of synapses between adjacent neuronal types. Structures of the eye Retina – section – H&E – 40x objective outer nuclear layer optic nerve fibers choroid pigmented epithelium ganglion cell layer layer of rods and cones outer plexiform layer inner nuclear layer inner plexiform layer

6. Cochlea – longitudinal section – H&E – 4x objective The cochlea is a coiled structure, turning 2.75 times about a central axis (the modiolus). So, you see the same tube multiple times in the same structure. Structures of the ear bony cochlea vestibule modiolus petrous portion of the temporal bone

7. Cochlea – longitudinal section – H&E – 10x objective During histological processing the delicate tectorial membrane breaks free from its attachment and curls back on itself. Structures of the ear spiral ganglion scala tympani basilar membrane spiral organ of Corti vestibular membrane scala media (cochlear duct) scala vestibuli tectorial membrane (torn free)

8. Cochlea – longitudinal section – H&E – 40x objective The spiral organ consists of hair cells, the stereocilia of which are embedded in the overlying tectorial membrane, and support cells. Structures of the ear scala tympani basilar membrane spiral organ of Corti vestibular membrane scala media (cochlear duct) scala vestibuli tectorial membrane