Site where Eyebrow conjunctiva Eyelid merges with cornea Eyelashes Palpebral Pupil fissure Lacrimal caruncle Lateral Medial commissure commissure (canthus) (canthus) Iris Sclera (covered by Eyelid conjunctiva) © 2018 Pearson Education, Inc. 1 Lacrimal Excretory duct gland of lacrimal gland Conjunctiva Anterior aspect Eyelid Eyelashes Tarsal glands (a) Eyelid © 2018 Pearson Education, Inc. 2 Lacrimal Lacrimal sac gland Excretory ducts of lacrimal gland Lacrimal canaliculus Nasolacrimal duct Inferior meatus of nasal cavity Nostril (b) © 2018 Pearson Education, Inc. 3 Superior oblique muscle Superior oblique tendon Superior rectus muscle Conjunctiva Lateral rectus muscle Optic Inferior Inferior nerve rectus oblique (a) muscle muscle © 2018 Pearson Education, Inc. 4 Sclera Ciliary body Choroid Ciliary zonule Retina Cornea Fovea centralis Iris Pupil Optic nerve Aqueous humor (in anterior segment) Lens Scleral venous sinus Central artery (canal of Schlemm) and vein of Vitreous humor the retina (in posterior segment) Optic disc (blind spot) (a) © 2018 Pearson Education, Inc. 5 Pigmented layer of retina Rod Cone Bipolar cells Ganglion Pathway cells of light (a) © 2018 Pearson Education, Inc. 6 Pigmented layer of Neural layer retina of retina Central artery and vein of retina Optic disc Sclera Optic (b) nerve Choroid © 2018 Pearson Education, Inc. 7 Visible light 420 nm 530 nm (blue cones) (green cones) 560 nm (red cones) Light absorption by cone populations cone by absorption Light 400 450 500 550 600 650 700 Wavelength (nanometers) © 2018 Pearson Education, Inc. 8 Fovea Macula Blood Optic disc Retina centralis vessels Lateral Medial © 2018 Pearson Education, Inc. 9 External (outer) ear Middle ear Internal (inner) ear Vestibulocochlear nerve Auricle (pinna) Semicircular canals Oval window Cochlea Vestibule Round window Pharyngotympanic (auditory) tube Tympanic membrane (eardrum) Hammer Anvil Stirrup (malleus) (incus) (stapes) External acoustic meatus Auditory ossicles (auditory canal) © 2018 Pearson Education, Inc. 10 Semicircular canals Ampulla Vestibular nerve Vestibule (a) © 2018 Pearson Education, Inc. 11 Force of Otolithic Otoliths gravity membrane Hair cell Head upright Head tilted (b) © 2018 Pearson Education, Inc. 12 Flow of endolymph Cupula Nerve fibers Direction of body (c) movement © 2018 Pearson Education, Inc. 13 Temporal Perilymph in scala vestibuli bone Spiral Vestibular organ of membrane Corti Afferent fibers of the cochlear nerve Temporal bone Cochlear duct (contains Perilymph in endolymph) scala tympani (a) © 2018 Pearson Education, Inc. 14 Vestibular Hair (receptor) Tectorial membrane cells of spiral membrane organ of Corti Fibers of Basilar Supporting the cochlear membrane cells nerve (b) © 2018 Pearson Education, Inc. 15 EXTERNAL EAR MIDDLE EAR INTERNAL EAR Auditory Ear- Oval Fluids in cochlear canals Pinna Hammer, canal drum anvil, stirrup window Upper and middle lower Pressure Spiral organ Time Amplitude Amplification One in middle ear of Corti vibration stimulated © 2018 Pearson Education, Inc. 16 Stapes Fibers of Scala sensory vestibuli neurons Oval Perilymph window Round Scala Basilar Cochlear window tympani membrane duct (a) Fibers of basilar membrane Apex Base (short, (long, stiff fibers) floppy fibers) 20,000 2,000 200 20 (High notes) (Low notes) (b) Frequency (Hz) © 2018 Pearson Education, Inc. 17 Olfactory bulb Cribriform plate of ethmoid bone Olfactory tract Olfactory filaments of the olfactory nerve Supporting cell Olfactory Olfactory receptor mucosa cell Olfactory hairs Mucus layer (a) (cilia) Route of inhaled air containing odor molecules (b) © 2018 Pearson Education, Inc. 18 Epiglottis Palatine tonsil Lingual tonsil Foliate papillae Fungiform papillae (a) © 2018 Pearson Education, Inc. 19 Epithelium of tongue Taste bud Connective tissue Surface of the tongue Gustatory (taste) cell Basal cell Sensory nerve fiber Gustatory hairs (microvilli) emerging from a taste pore (c) © 2018 Pearson Education, Inc. 20.