BIOL 1412 Lecture Notes - Lecture 20: Optic Nerve, Fovea Centralis, Special Senses

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 1412
• Professor: Ibrahima Diallo

Document Summary

Topic xx: special senses: special senses: eye. When vessels dilate = bloodshot eyes: vascular tunic. Ciliary muscle + ciliary processes focus the lens: iris. Hole in iris: nervous (sensory) tunic = retina: Parts: outer pigmented layer, inner neural layer. 3 layers of neurons: photoreceptors (2 types) rods black +white cones - colour, bipolar cells, ganglion cells. Axons form optic nerve (cranial nerve ii: fovea centralis. Blind spot where blood vessels + optic nerve exit eye. Cataracts = clouding of lens: anterior segment. Fluid similar to plasma: posterior segment. Elastic cartilage, covered with skin: external auditory (acoustic) canal (meatus, tympanic membrane (eardrum, middle ear. Also called pharyngotympanic tube: ear ossicles, malleus. Secured to tympanic membrane: incus, stapes. Transmits sound to inner ear via oval window: inner ear (labyrinth) Each coil has 3 channels: scala vestibuli. Between cochlear duct + scala vestibuli: basilar membrane. Between cochlear duct + scala tympani: tectorial membrane. Covers hair cells (= receptor cells: receptors in inner ear.