the dendrites of the olfactory cells extending out of the epithelial surface, where they expand into olfactory vesicles "OV" which radiate numerous snake-like cilia in all directions. "modified cilia" ("MC"). apical microvilli ("Mv"). when they withdraw downwards they leave an opening, the "Op"
"a" is a sectioned optic nerve, and "b" is the retina, the photosensitive layer that is directly responsible for light reception. Label "c" is the lens, whose shape is altered by ciliary muscle for focusing. Structure "d" is the iris, a circular curtain of tissue that regulates the amount of light entering the eye. Finally, "e" is the cornea, which admits light and contributes to light refraction (the bending of incoming light rays).
a scanning electron micrograph of the choroid and the sclera layers of the eye. The sclera is seen at the bottom as a thick layer of closely packed collagenous fibers "CF" all running parallel left to right. Above the sclera is the choroid ("Ch") layer which is subdivided into three layers: (1) the outer vessel layer "VL", (2) the inner capillary layer "CL", and (3) an innermost Bruch's membrane "BM" which is a thin glassy membrane that contacts the "PE", the pigmented epithelium of the retina. Just above the pigmented epithelium is shown the outer broken segments of the rods ("RC").
the purple stripe on the bottom of the image which stretches across the thickness of the choroid. The choroid is darkly pigmented and it contains many blood vessels. The purplish layers of the retina lie above the choroid in this slide.
the overall retina structure: "a" lies within the choroid coat, with the pigmented layer of the retina running vertically just to the right. "b" lies among a portion of the rods and cones called the outer segment. "c" lies among the cell bodies of the rods and cones. "d" lies among the synaptic connections between the rod and cones and the bipolar cells. "e" lies among the cell bodies of the bipolar, horizontal and amacrine cells. "f" lies among the axons of the bipolar cells and dendrites of the ganglion cells. "g" lies among cell bodies of ganglion cells
a view of the back of the retina as a doctor would view it through an opthalmoscope. The center of the image is dominated by the optic disc (the blind spot), from which blood vessels radiate to the entire eye. Lateral to the optic disc is the macula lutea (yellow spot), on the left edge of the circular, illuminated field. In the center of the macula is a depression, the fovea centralis
the backside of the pupil, iris, and ciliary body as if you were inside the eye looking out forward. The lens has been removed so that you can see the structures more clearly. "Pu" marks the pupil, and "Ir" is a greatly dilated iris. "CP" is the ciliary process, part of the ciliary body which secretes the aqueous humor
"a" marks the muscular layer of the iris, and "b" lies on the pigmented layer. Feature "c" marks the lens epithelium, from which new cells are constantly added to the lens cortex. And "d" lies in the lens proper.
The arrow indicates the ciliary body, which contains smooth muscles that alter the shape of the lens by their contraction and which also secretes aqueous humor from its folded border, the ciliary process.
overview of the external (outer) ear, which is highlighted in an orange color. Note the outermost funnel-shaped pinna (or auricle) which captures sound waves and passes them inwardly through the tube, the external auditory meatus, to eventually bounce against the eardrum.
the middle ear. The tympanic membrane and the ossicles are shown in light blue, while the darker blue represents the middle ear cavity and an attached tube, called the pharyngotympanic (auditory) tube which connects the middle ear to the pharynx.
a ripped open view of the middle ear. The three little bony ossicles-the malleus "Ma", the incus "In", and the stapes "St"-are clearly visible. Also visible is the rounded lenticular process "LP" of the incus and the large footplate "FP" of the stapes. These bones sit in a hollow cavity called the tympanic cavity "TC" which is surrounded by temporal bone "TB". To the right of the footplate you can see the inner ear cavity, the vestibule "Ve" which is normally filled with fluid.
the several types of synovial joints between the ossicles: (1) the saddle joint between the malleus and the incus, (2) the ball-and-socket joint between the incus and the stapes, and (3) the hinge joint of the stapes.
the membranous labyrinth is seen in iridescent purple-silver color. Inside this membrane structure is found a fluid called endolymph (so labeled). Outside of the membranous labyrinth is another fluid (shown in orange), called perilymph. The outer black outline follows the margin of the inner ear: this is the osseous labyrinth
"a" marks the cochlear branch of Cranial Nerve VIII, running through the central bony core (the modiolus). Structure "b" marks the scala vestibuli, "c" marks the cochlear duct, and "d" marks the scala tympani
a closer view of the cochlea. Structure "a" marks the vestibular membrane, with the scala vestibuli immediately above; "b" marks the basilar membrane, with the hair cells of the Organ of Corti (spiral organ) lying directly superior; "c" marks the cochlear branch of the vestibulocochlear nerve.
the workings of the macula. The blue arrow indicates the direction of shift taking place in the gel cap, causing the hairs to flex. The "sticks of chalk" in the upper left corner are otoliths, and when they shift the ciliary hairs bend, causing the brown-colored neurons to fire.
an actual photograph of a crista ampullaris. The "Cu" is the cupula which radiates gelatinous strands ("St") outwardly to contact the longest cilia of the hair cells ("HC") which are held up by a layer of polygonal supportive cells ("SC"). The snowflake shape is the tip of the cupula.