1 1 The Senses Laboratory
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The SensesLaboratory
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The Variety of Senses
Mechanoreceptors – proprioceptors, touch, pressure, hearing, balance, pressure, vibration, movement
Chemoreceptors – taste, smell, visceral senses (O2, CO2, pH, etc.)
Thermoreceptors – hot and cold
Nociceptors – pain
Photoreceptors – vision
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The Special Senses
Based on the complexity of the receptors:
Taste
Smell
Vision
Hearing and balance
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Taste
Taste bud
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Circumvallate papillae
Taste cells
microvilli
Basal cellsFigure 16.1
Taste buds – groups of taste cells located on papillae of tongue as well as hard palate and epiglottis.
• circumvallate papillae – large, round, back of tongue.•filiform papillae – no taste buds, near tip, touch receptors.
•fungiform papillae – most abundant, over most of tongue.
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Fungiform Papillae on the Tongue
Taste budsStratified squamous epithelium
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Lateral View of the Eye
Figure 16.5
Levator palpebrae sup.
Sup. Rectus
Lat. Rectus
Inf. Rectus
Orbicularis oculi
Ocular conjunctiva Conjuctival sac Palpebral conjunctiva
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Anterior View of Eye
Figure 16.5
Lacrimal gland
Lacrimal canal
Lacrimal sac
Nasolacrimal duct
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Extrinsic Muscles of the Eye
Sup. Oblique m.
Sup. Oblique tendon
Trochlea
Lat. Rectus m.
Med. Rectus m.
Inf. Oblique m.
Inf. Rectus m.Lat. Rectus m.
Sup. Rectus m.
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Anatomy of the Eye
Sclera
Cornea
Anterior segment (contains aqueous
humor)Canal of Schlemm
Figure 16. 7
Vitreous body
Choroid coatRetina
Ciliary body
Suspensory lig.
Iris
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Sagittal Section
cornea
iris
anterior chamber
lens
posterior chamber
ciliary body
ora serrata
retina
choroid
sclera
optic diskSuspensory ligament
Posterior segment (vitreous body)
Anterior segment
muscle insertion
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Dissection of the Eye: The Optic Nerve
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Sheep Eye Cornea
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Sheep Eye Vitreous Humor
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Sheep Eye: Vitreous Humor and Lens
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Sheep Eye: Choroid Coat and Retina
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Sheep Eye: Ciliary Disk and Iris
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The Tapetum Lucidum
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Cadaver Eye Dissection
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The Ear
Auricle
External auditory canal
External ear
Middle ear Inner ear
Figure 16.24
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Middle and Inner EarOssicles: stapes incus malleous
Int. jugular v. Eustachian canal
Round window
Semicircular canals
Cochlea
Vestibule
Vestibular n. cochlear n.
of VIII
Tympanic membrane
Oval window
Figure 16.24
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Lab ProtocolI. The Eye: Exercise 24
A. Materials:
1. micro slides
2. Cadaver dissections: excised and in situ eye dissections
2. sheep eyes, one per 3-4 students
3. eye models, vision chart
` B. Procedures:
1. Identify indicated parts in models and specimens and relate structures to their functions.
2. Sheep eye dissection – relate to human eye.
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II. The Ear: Exercise 25
A. Materials:
1. cadaver dissection
2. ear models, tuning forks
B. Procedures:
1. Identify indicated parts in models and specimens and relate structures to their functions.
2. Perform selected tests and experiments in lab manual.