Chapter 9.3: The Senses

Taste Pathways Facial, Glossopharyngeal and Vagus Trigeminal—gives us “peppery and spicy hot” Several thousand times more sensitive to taste when smell is involved

Vision Accessory Structures Palpebrae—Eye lids Lubricate Free from dust Protect

Figure 9.8a

Accessory cont… Eyelashes Protections

Figure 9.8a

Accessory cont… Sebaceous Glands In eyelashes Keeps eyelids from sticking Sty—Painful swelling Due to bacterial infection

Accessory cont… Conjunctiva Membrane over eye Very sensitive Conjunctivitis AKA: Pinkeye Damage/irritation to conjunctiva

Accessory cont… Lacrimal Apparatus Produces, distributes and removes tears Constantly “crying” Moistens and cleans Reduce friction Remove debris Prevent bacterial infection Provide nutrients and oxygen to conjunctiva

Figure 9.8b

Accessory cont… Nasolacrimal duct Connects eye to nose

Figure 9.8b

Accessory cont… Extrinsic eye muscles Control eye position

Figure 9.9a

The Eye Fibrous Tunics Outermost layer of the eye Support and protection Attachment site for muscles Assists in focusing

Figure 9.10b

Fibrous tunics cont… Sclera White of the eye Muscles insert here

Figure 9.10b

Fibrous cont… Cornea No blood vessels Limited repair

Figure 9.10b

Figure 9.10a

Vascular tunics Blood vessels for the eye Regulates light into eye Controls shape of lens

Figure 9.10b