Chapter 9.3: The Senses

Chapter 9.3: The SensesTaste PathwaysFacial, Glossopharyngeal and VagusTrigeminalgives us peppery and spicy hotSeveral thousand times more sensitive to taste when smell is involvedVisionAccessory StructuresPalpebraeEye lidsLubricateFree from dustProtectFigure 9.8a

Accessory contEyelashesProtectionsFigure 9.8a

Accessory contSebaceous GlandsIn eyelashesKeeps eyelids from stickingStyPainful swellingDue to bacterial infection

Accessory contConjunctivaMembrane over eyeVery sensitiveConjunctivitisAKA: PinkeyeDamage/irritation to conjunctiva

Accessory contLacrimal ApparatusProduces, distributes and removes tearsConstantly cryingMoistens and cleansReduce frictionRemove debrisPrevent bacterial infectionProvide nutrients and oxygen to conjunctivaFigure 9.8b

Accessory contNasolacrimal ductConnects eye to noseFigure 9.8b

Accessory contExtrinsic eye musclesControl eye positionFigure 9.9a

The EyeFibrous TunicsOutermost layer of the eyeSupport and protectionAttachment site for musclesAssists in focusingFigure 9.10b

Fibrous tunics contScleraWhite of the eyeMuscles insert hereFigure 9.10b

Fibrous contCorneaNo blood vesselsLimited repairFigure 9.10b

Figure 9.10a

Vascular tunicsBlood vessels for the eyeRegulates light into eyeControls shape of lensFigure 9.10b