Lab 6 Vision, Eyeball Movement & Balance System I… Yes, unfortunately there is a II

1 2 Lens 3 4 5 6 7 8 Suspensatory Ligament 9

1 2 3 4 Ciliary Body Suspensatory Ligament 5 6

3 2 Canal of Schlemm 1 9 6 8 10 4 Suspensatory Ligament 5 11 7 What fills this space? Vitreous Body 12 13 Ciliary Arteries 14 15 16

2 1

Start with A B C A Vitreous Body Retina Lens Eyeball Sphenoidal Sinus Hypophysis Optic Nerve Temporal Lobe Gray Matter Basilar Artery CSF in Sulcus Pons 4th Ventricle Cerebellum Start with A

3 4 5 1 2 6 7 8 9 10 3 LAYERS: OUTER: sclera cornea MIDDLE: Iris ciliary body choroid INNER: retina 6 7 Anterior chamber 8 LENS Posterior chamber 9 10 VITREOUS BODY

Horizontal section through anterior eyeball Lens Cornea Anterior chamber Conjunctiva Ciliary body: ciliary processes ciliary muscle Limbus Posterior chamber 3 1 4 2 (space) iris Dilator pupillae muscle 7 6 Constrictor Pupillae m. 5 (space) 10 9 8 Horizontal section through anterior eyeball

Anterior chamber Posterior chamber Iris Dilator pupillae Pigmented posterior epithelium Dilator pupillae Constrictor pupillae Lens fibers ----Pupil---- 1 2

Optic disc Pia-arachnoid Dura mater Optic nerve Sclera Central retinal vessels Pia-arachnoid Dura mater Sclera Optic disc Retina Choroid 1 2 3

4 1 3 (space 2 6 5 7 Ciliary body Anterior chamber lens Posterior iris cornea 6 Ciliary processes suspensory ligament 5 7 Ciliary muscle Ciliary body

Lens fibers Lens epithelium Lens capsule Ciliary muscle Iris Ciliary processes Posterior chamber Anterior chamber Canal of Schlemm 2 1 3 (space) 4 6 5 (space)

Cornea of the eye Anterior chamber Corneal endothelium CORNEAL STROMA 1 (space) Anterior chamber 2 Corneal endothelium 3 CORNEAL STROMA Corneal epithelium 4 Cornea of the eye

VITREOUS BODY 3 1 2 7 4 5 8 6 LAYER OF GANGLION CELL AXONS (invisible) BIPOLAR CELLS LAYER OF GANGLION CELLS 1 2 FOVEA 7 CHOROID LAYER ORBIT PIGMENT EPITHELIUM 4 LAYER OF ROD & CONE SEGMENTS 5 Retina LAYER OF ROD & CONE CELLS 8 6

Histology of retina Pigment epithelium SCLERA Ganglion cell axons Ganglion cell layer Inner nuclear layer Cell bodies of rods and cones Outer segments of rods and cones CHOROID SCLERA Pigment epithelium 3 1 4 2 5 6 7 8 Histology of retina

1 2 3 4 5 6

Where is the calcarine cortex located? 1 2 3 Calcarine Cortex (V1, Area 17) is along banks of calcarine sulcus Where is the calcarine cortex located? V2 and V3 surround V1 Where are the secondary & tertiary visual cortex?

1 2 Chiasmatic Groove

optic radiations 1

1 2 3 4

1 2 3 4

Where is the optic tract located? LGN Optic Tract Where is the optic tract located? Where is the lateral geniculate nucleus located?

1 Primary visual cortex, occipital lobe visual radiations 2

1 Optic radiations 4 Optic radiations 2 Optic tract 3 LGN Midbrain-diencephalon junction, transverse section, myelin stain (Martin)

1 2 3 5 4 Optic tract midbrain Visual radiations Lateral Ventricle TEMPORAL LOBE 3 Lateral Ventricle 5 Primary visual cortex 4 OCCIPITAL LOBE

1 3 2 4 5 6 Optic tract passing position of Position of optic tract lateral to hypothalamus position of optic nerve Position of optic tract (lateral to hypothalamus) 1 3 Optic chiasm 2 hypothalamus 4 stalk of hypophysis 5 6 hypophysis

2 HYPOPHYSIS 1 OPTIC CHIASM OPTIC TRACT 3 INTERNAL CAROTID ARTERY

1 6 2 7 3 8 5 4 9 thalamus midbrain temporal temporal lobe lobe upper fibers of visual radiations 8 Meyer’s Loop 5 atrium 4 calcarine cortex temporal horn of lateral ventricle 9

Lower retina (upper visual field) What are the 5 L’s? Lower retina (upper visual field) Lateral part of LGN Loop of Meyer = Lower part (temporal) of optic radiations Lingual Gyrus In the conscious visual path, impulses travel from receptors in the retina to the visual cortex for perception of light stimuli. Visual impulses traverse rod and cone, bipolar, and then ganglion cells in the retina. Axons of ganglion cells exit the eyeball in the optic nerve and traverse the optic tract (after 50% decussation in the chiasm). The optic tract terminates in the lateral geniculate nucleus of the thalamus. Thalamic neurons then send axons through the optic radiations (retrolenticular fibers) to the primary visual (calcarine) cortex.