NeuroHisto Slides/Quiz

1. B. Dupree NeuroHisto Slides/Quiz Part 2 - Eye • Instructions: • View in SLIDE SHOW to get the full effect!!! • TURN SOUND ON!!! • Take your time…Don’t get click-happy • NOTE: These are the exact slides from the HISTO CD, but more fun.

2. Eyelid, 5 Orbicularis Oculi Muscle - skeletal muscle that is used to close the eyelid. Tarsal Plate with Meibomian Glands - the tarsal plate is composed of dense connective tissue. The Meibomian glands (sebaceous type glands) are embedded in it. Obicularis Oculi Muscle Conjunctiva Tarsal Plate with Meibomian Glands Follicles of Eyelashes

3. Eyelid, 5 Obicularis Oculi Muscle

4. Eyelid, 5 Duct of Meibomian Glands - the duct sectioned in this slide would drain the glandular elements in this field. Additional glands and ducts are found along the length of the tarsal plate. The secretion of these glands serves to lubricate the movement of the lid and also help move the tears toward the lacrimal puncta. Conjunctiva Meibomian Glands in Tarsal Plate Duct of Meibomian Glands

5. Eyelid, 5 Meibomian Glands Meibomian Glands - sebaceous type glands embedded in the tarsal plate. Glands of Moll - modified apocrine sweat glands associated with the follicles of the eye lashes. Glands of Zeis - sebaceous glands associated with the follicles of the eye lashes. Obicularis Oculi Muscle Glands of Moll Follicle Glands of Zeis

6. Eye, 183 Fibrous Layer: Sclera - white of the eye made up primarily of collagen. Cornea - composed of several layers supported by a substantia propria predominantly composed of a special transparent collagen. Vascular Layer (Uvea): Choroid - vascular tissue with pigment. Ciliary Body - has ciliary processes and ciliary muscles. Iris - has dilator and sphincter pupillae muscles, a vascular stroma and pigment layers. This section is cut to the side of the pupil so that the iris appears as a continuous structure. Neural coat: Retina - light sensitive portion. Ora Serrata - Transition from light sensitive to non light sensitive portion of the neural coat. This coat continues anteriorly as inner layers of the ciliary body and iris. Cornea Iris Lens Ciliary Body Retina Choroid Ora Serrata Lacrimal Gland Sclera

7. Eye, 183 Retina Retina - light sensitive part of the neural coat. Choroid - vascular coat that supports the retina and supplies the outer portion of the retina with oxygen, nutrients, etc. Sclera - dense white fibrous (collagenous) tissue. Choroid Sclera

8. Eye, 183 Inner Limiting Membrane Optic Nerve Fiber Layer Ganglion Cell Layer Retina Inner (external) Plexiform Layer Inner (external) Nuclear Layer Outer (external) Plexiform Layer Outer (external) Nuclear Layer Layer of Rods & Cones Pigment Cell Layer Choroid Choriocapillary Layer Sclera Choriocapillary Layer - essential for the maintenance of the retina.

9. Eye, 183 Inner Limiting Membrane Vessel from Central Artery Optic Nerve Fiber Layer Ganglion Cell Layer Inner (external) Plexiform Layer Inner (external) Nuclear Layer Retina Outer (external) Plexiform Layer Outer (external) Nuclear Layer Layer of Rods & Cones Pigment Cell Layer Choroid Choriocapillary Layer Sclera

10. Eye, 183 Ora Serrata Ora Serrata - transition form the light sensisive to non light sensitive part of the neural coat that continues as inner layers of the ciliary body and the iris. In this section the retina is detached and the continuation of the neural coat beyond the ora serrata is detached also.

11. Eye, 183 Iris Cornea Canal of Schlemm Ciliary Processes Ciliary Muscle Ciliary Processes - folds extending from the ciliary body. Ciliary Muscle - smooth muscle that functions to decrease tension on the suspensory fibers of the lens. This decrease in tension allows the lens to become more rounded for close focusing. Canal of Schlemm - this is a canal into which the aqueous humor drains from the anterior chamber of the anterior cavity.

12. Eye, 183 Ciliary Processes Ciliary Muscle Ciliary Processes - the neural coat continues over the ciliary body and processes as a nonpigmented and pigmented layer. These epithelial layers assist in the formation of the aqueous humor that is found in the anterior cavity of the eye.

13. Eye, 183 Remnants of the Lens Iris Iris - there is no pupil in this section. See the "Low" image for the description of the layers. Remnants of the Lens - most of the lens fibers have been lost from this section.

14. Eye, 183 Pigment Layer - represents the continuation of the neural coat to the back of the iris. It is actually two layers of epithelium. The nonpigmented layer that is present over the choroid body becomes pigmented as it continues onto the iris. Stroma of Iris - vascular connective tissue with some pigmented cells associated with it. Dilator of Pupil - is modified smooth muscle that is closely associated with the pigment layer and therefore somewhat difficult to identify. Pigment Layer Stroma of Iris Dilator of Pupil

15. Eye, 183 Epithelium Endothelium There are five layers to the cornea, three of which are labeled on this image. Epithelium - stratified epithelium on the outer surface of the cornea. It is exposed to tears and air. Substantia Propria - avascular dense fibrous tissue. It is predominantly composed of transparent collagen. Endothelium - single layer of cells that lines the inside of the cornea. It is bathed in aqueous humor. Substantia Propria

16. Eye, 183 Stratified Squamous Epithelium Bowman’s Membrane Bowman's Membrane - extremely thick basement membrane that underlies the stratified squamous epithelium on the surface of the cornea. Substantia Propria

17. Eye, 183 Endothelium Substantia Propria Descemet’s Membrane Descemet's Membrane - basement membrane underlying the endothelium.

18. Eye, 183 (Demonstration) Eye - Demonstration - This is a section from the same slide as 183, but this section is cut through the pupil and optic papilla. Optic Papilla (Optic Disk,Blind Spot) - exit point for optic nerve fibers and the central vein and the entry point for the central artery. Iris Optic Papilla (Optic Disk) Pupil Lens

19. Eye, 183 (Demonstration) Subarachnoid Space Optic Papilla (Optic Disk) Optic Nerve Branch of Central Artery (or Vein)

20. Eye, 183 (Demonstration) Lens Pigment Spot Sphincter of the Iris Pigment Spot - almost all individual have these darker spots on their iris. They show up especially well in light colored eyes. Sphincter of the iris - this muscle surrounds the pupil and allows for constriction of the pupillary opening. Pupil

21. Eye, 183 (Demonstration) Pigment Cells in Stroma Pigment Layer Pigment Layer - this layer, on the back of the iris, is actually composed of two layers of cells and is present in all individuals except albinos. If there is little pigment in the stroma (anterior to the pigment layer), as is the case in this eye, the result is a light eyed individual. A dark eyed person has large amount of pigment in the stroma. Pigment Spot - almost all individual have these darker spots on their iris. They show up especially well in light colored eyes. Sphincter of the iris - this muscle surrounds the pupil and allows for constriction of the pupillary opening. Pigment Spot Spincter of the Iris

22. Eye - Fetal, 182 Conjunctival Sac Eyelid Cornea This slide shows the extent of the conjunctival sac and the immature layers of the eye. The retina and the choroid are both detached. Conjunctival Sac - The posterior side of the eyelid is lined by the palpebral conjunctiva. The anterior portion of the eyeball up to the cornea is lined by the bulbar conjunctiva. The point where the two conjunctival layers meet is called the fornix.

23. Eye - Fetal, 182 Eyelid Palpebral Fissure Cornea Eyelid

24. The End Thanks to Dr. DeSha for the images!!!

25. B. Dupree NeuroHisto Slides/Quiz Part 3 - Ear • Instructions: • View in SLIDE SHOW to get the full effect!!! • TURN SOUND ON!!! • Take your time…Don’t get click-happy • NOTE: These are the exact slides from the HISTO CD, but more fun.

26. Human Temporal Bone, Special Slide This is a horizontal section of a decalcified human temporal bone Middle Ear - This is a space lined with a thin mucous membrane and is filled with air in life. Pieces of bone in the space are those of the auditory ossicles. InnerEar: Vestibule - This is a space filled with perilymph . In this perilymph space there are membrane structures that contain endolymph, the saccule and utricle. Semicircular Canals - These are also parts of the inner ear that contain perilymph. There are endolymph structures called semicircular ducts in these spaces. Cochlea - This is a coiled structure containing perilymph. It houses an endolymph tube called the cochlear duct. Internal Carotid Artery - lies adjacent to the cochlea, thus, sometimes, a pulse can be heard. Internal Auditory Meatus - The continuity between this space and the posterior cranial fossa is not seen on this section. Semicircular Canals Internal Auditory Meatus Cochlea Internal Carotid Vestibule Tympanic Membrane Middle Ear

27. Human Temporal Bone, Special Slide Helicotrema This view of the cochlea is turned 180º from that of the cochlea labeled in the overview below. In was photographed with a 2.5x scanning lens so the full extent of the human cochlea could be seen. Modiolus - central bony core of the cochlea. Osseous Spiral Lamina - Extension of bone from the modiolus that projects toward the cochlear duct. Cochlear Duct (Scala media) - Contains endolymph and the organ of Corti. Helicotrema - point where the perilymph in scala vestibuli becomes continuous with scala tympani. Modiolus Scala Media (Cochlear Duct) Osseous Spiral Lamina

28. Human Temporal Bone, Special Slide Scala Vestibuli Scala Media (Cochlear Duct) Scala Tympani

29. Human Temporal Bone, Special Slide Stria Vascularis Vestibular Membrane Scala Vestibuli Scala Vestibuli - contains perilymph which is continuous with that of the vestibule. Scala Tympani - contains perilymph which is continuous with that of scala vestibuli at the helicotrema. The scala tympani ends at the secondary tympanic membrane which seals off the round window. Scala Media (Cochlear Duct) - contains endolymph and the organ of Corti. Tectorial Membrane - structure that overlies the hair cells of the organ of Corti. Vestibular Membrane - separates scala vestibuli from the cochlear duct. Basilar Membrane - is one of the structures that separate the cochlear duct form the scala tympani. Some of the support cells of the organ of Corti rest on the membrane. Osseous Spiral Lamina - bony extension from the modiolus that anchors one end of the basilar membrane. Spiral Ligament - anchors the other end of the basilar membrane. Stria Vascularis - structure in the cochlear duct that produces endolymph. Scala Media (Cochlear Duct) Tectorial Membrane Osseous Spiral Lamina Spiral Ligament Basilar Membrane Scala Tympani Organ of Corti

30. Human Temporal Bone, Special Slide Semicircular Duct Semicircular Canal Semicircular Canal - perilymph space Semicircular Duct - structure containing endolymph

31. Human Temporal Bone, Special Slide Endolymph in Saccule Otolithic Membrane What kind of lymph is in each space? Epithelium of Macula Region of the macula in what is probably the saccule: Otolithic Membrane - This structure contains otoconia that are particles of calcium carbonate. (not easily distinguished in this view - The dark purple staining structures in the membrane to the side of the label line are artifacts, not otoconia.) Epithelium of Macula - This is composed of sensory hair cells and support cells, but neither of these cell types can be distinguished in this view. Branch of Vestibular Nerve (CN VIII) Perilymph in Vestibule

32. Ear, Animal, Special Slide Cochlea Vestibule Cochlear Division of CN VIII

33. Ear, Animal, Special Slide Scala Vestibuli Scala Tympani Scala Media (Cochlear Duct) Tectorial Membrane Vestibular Membrane Osseous Spiral Lamina Basilar Membrane Stria Vascularis Spiral Ligament

34. Ear, Guinea Pig – __________, Etc. Cochlea Vestibule

35. Ear, Guinea Pig – __________, Etc. Ear, Guinea Pig – Helicotrema, Etc. Helicotrema Modiolus Spiral Ganglion Cells

36. Ear, Guinea Pig – Helicotrema, Etc. Scala Vestibuli Vestibular Membrane Stria Vascularis Scala Media (Cochlear Duct) Tectorial Membrane Osseous Spiral Lamina Organ of Corti Spiral Ligament Basilar Membrane Scala Tympani

37. Ear, Guinea Pig – Helicotrema, Etc. Bone of Modiolus - central core of bone supporting the cochlea. Osseous Spiral Lamina - shelf of bone from the modiolus. Spiral Ganglion Cells - bipolar neurons. Spiral Limbus - structure to which the base of the tectorial membrane is anchored. Tectorial membrane - structure associated in life with the hairs of the hair cells. Vestibular membrane -separates the scala vestibuli from the cochlear duct. Vestibular Membrane Scala Vestibuli Bone of Modiolus Scala Media (Cochlear Duct) Tectorial Membrane Spiral Limbus Scala Tympani Osseous Spiral Lamina Spiral Ganglion Cells

38. Ear, Guinea Pig – Helicotrema, Etc. Basilar Membrane - Structure which vibrates in response to vibrations in perilymph and endolymph. Pillar Cells - supporting cells with numerous microtubules and microfilaments that account for these cells being very stiff supporting cells. Outer Hair Cells - Three or four in number in a section, since there are three to four rows of these depending on the location in the cochlea. These are receptor cells. Inner Hair Cell - A single cell in a section since there is only a single row of inner hair cells. These are also receptor cells. Outer Hair Cell Inner Hair Cell Pillar Cell Basilar Membrane

39. Ear, Guinea Pig – __________________________ Ear, Guinea Pig – Crista Ampullaris and Maculas Crista ampullaris - This is a ridge covered with a sensory epithelium that is located in the ampulla of the semicircular duct. This duct contains endolymph. It is housed in a perilymph space, the semicircular canal. Macula of utricle - Sensory structure in the endolymph containing utricle. The utricle is surrounded by the perilymph of the vestibule. Macula of saccule - Sensory structure in the endolymph containing saccule. The saccule is also housed in the perilymph of the vestibule. Crista Ampullaris Macula of Saccule Macula of Utricle

40. Ear, Guinea Pig – Crista Ampullaris and Maculas Crista Ampullaris Macula of Utricle Macula of Saccule

41. Ear, Guinea Pig – Crista Ampullaris and Maculas Utricle - endolymph structure of the vestibule surrounded by perilymph. Utricle Otolithic Membrane Epithelium of Macula

42. Ear, Guinea Pig – Crista Ampullaris and Maculas Epithelium of Macula Otolithic Membrane Otolithic Membrane - structure of the macula which has otoconia (not visible as individual particles at this magnification) that overlies the sensory epithelium. Epithelium of Macula - composed of hair cells (sensory) and supporting cells. A branch of the vestibulocochlear nerve supplies this epithelium.

43. Ear, Guinea Pig – __________________________ Ear, Guinea Pig – Crista Ampullaris and Maculas Ampulla of the Semicircular Canal Ampulla of the Semicircular Duct Crista Ampullaris Vestibule Ampulla of Semicircular Canal - This is an expanded portion of the semicircular canal. It contains perilymph. Note its continuity with the vestibule. Ampulla of the Semicircular Duct - This is an expanded region of semicircular duct. It contains endolymph. Crista Ampullaris - This is ridge of tissue covered by the sensory epithelium.

44. Ear, Guinea Pig – __________________________ Ear, Guinea Pig – Crista Ampullaris and Maculas Cupula Epithelium of Crista Ampullaris Cupula - A gelatinous material that overlies the hair cells that are part of the sensory epithelium. Epithelium of Crista - composed of sensory (hair cells) and supporting cells. These cannot be distinguished from one another in these sections. Processes of the vestibular portion of the vestibulocochlear VIII nerve innervate the hair cells.

45. The End Thanks to Dr. DeSha for the images!!!