chapter 17 Flashcards
Axons Leaving Olfactory Epithelium
- collect into 20+ bundles
- Generate cribriform plate of the ethmoid
- Reach olfactory bulbs of the cerebrum where first synapse occurs
Axons Leaving Olfactory Bulb
- Travel along olfactory tract to reach olfactory cortex, hypothalamus, and protons of limbic system
- Arriving information reaches information centers without first synapsing thalamus
Taste buds are associated with ?
- Associated with epithelial projections (lingual papillae(not taste buds)) on dorsal surface of tongue
- 5 elements of taste perceptions:
–sweet
–salty
–bitter
–sour
–umami
What are the 3 types of Lingual Papillae?
- Filiform papillae:
–provide friction
– do not contain taste buds - Fungiform papillae:
–contain 5 taste buds each - Circumvallate papillae:
– contain 100 taste buds each
Taste buds monitored by what cranial nerves?
CN V & IX
Monitored by cranial nerves that synapse within solitary nucleus of medulla oblongata then on to thalamus and primary sensory cortex
Taste Sensitivity
Exhibits significant individual differences
-Some conditions are inherited:
–ex. phenylthiocarbamide (PTC):
– 70% of Caucasians taste it but 30% do not
Taste Sensitivity
Exhibits significant individual differences
-Some conditions are inherited:
–ex. phenylthiocarbamide (PTC):
– 70% of Caucasians taste it but 30% do not
Accessory Structures of the Eye
- Eyelids
- Superficial epithelium of eye
- Structures associated with production, secretion, and removal of tears
Eyelids (Palpebrae)
-Continuation of skin
-Blinking keeps surface of eye lubricated, free of dust, and debris
what is medial Canthus and Lateral Canthus?
Its where two eyelids are connected
Lacrimal Caruncle
-Mass of soft tissue
- Contains glands producing thick secretions
- Contribute to gritty deposits that appear after good night’s sleep
Conjunctiva
Epithelium covering inner surfaces of eyelids and outer surface of eye
Conjunctivitis (pinkeye)
Results from damage of conjunctival surface
what are the two types?
What does the Lacrimal Apparatus do
Produces, distributes, and removes tears
What does the lacrimal gland (tear gland) contain
Secretions contain lysozyme, an antibacterial enzyme
Where do tears pass through and reaches what?
Passes through
- lacrimal puncta
- lacrimal canaliculi
- lacrimal sac
- nasolacrimal duct
- reaches inferior meatus of nose
Eyeball
What separates the anterior from the posterior cavity?
is hollow
- divided into 2 cavities:
– large posterior cavity
– smaller anterior cavity
The lens separates the anterior form the posterior cavity
Orbital fat
cushions and insulates eye
Layers of the eye?
- Fibrous tunic(most superficial): Cornea and Sclera, limbus (border between cornea & sclera)
- Vascular Tunic(middle layer): Iris, Ciliary body (ciliary muscles included), and choroid
- Neural Tunic(deepest): Retina (contains photoreceptors..rods & cones)
What are the functions of Vascular Tunic (Uvea)?
- Provides a route for blood vessels and lymphatics that supply tissues of the eye
- Regulates amount of light entering eye
- Secretes reabsorbs aqueous humor that circulates within chambers of eye
- Controls shape of lens, which is essential for focusing
What does the Iris do?
Contains muscle fibers
Changes diameter of the pupil
Papillary Dilator Muscles
Enlarges pupil
Dilated eye contract = decreased light intensity & increased sympathetic stimulation
Constricted eye contract = increased light intensity & increased parasympathetic stimulation
Ciliary Body contains & function?
-Contains ciliary muscle and ciliary processes which attach to suspensory ligaments of lenses.
- All function change the shape of the Lens which allow us to focus on far/near objects
Neural Tunic (retina)
Most important for the structure of the eye
-Neural part and pigmented part
- Rods, cones are types of photoreceptors