Specails senses Flashcards
Olfactory epithelium
Highly modified nerve cells and detect dissolved chemicals.
What 4 structures are withing the lamina propria?
- Areolar tissue
- blood vessels
- nerves
- olfactory glands
What is the first step of olfactory reception?
Begins with binding of odorant to G protein-coupled receptor.
What happens after the G protein-coupled with a receptor?
Generator potential (depolarization)
What happens after a generator potential happens?
Afferent fibers leave olfactory epithelium and collect in 20 or more bundles.
After 20 or more bundles are collected what happens
Penetrates cribiform plate of ethmoid bone and reach olfactory bulbs of cerebrum where first synapse.
What happens after there is a cerebrum where first synapse occurs?
Axons leaving olfactory bulb travel along olfactory tract to olfactory cortex, hypothalmus and limbic system.
Olfactory information is the only type of sensory information to reach cerebral cortex _______.
Directly
What are the accessory structures of the eye (3)?
- Eyelids
- Conjuntiva
- Lacrimal apparatus
Palpebral fissure-gap that separates structures?
Free margins of upper and lower eyelids.
Eyelids are collected where?
Medial angle and lateral angle
Lacrimal caruncle
Mass of soft tissue at medial angle of eye and contains glands producing thick secretions.
Palpebral conjuctiva
Covers inner surface of eyelids.
Bulbar conjunctiva
Covers anterior surface of eye and extends to edges of cornea.
Fornix
Pocket where palpebral conjuntiva joins bulbar and receives 10-12 ducts from lacirmal gland.
Tears pass through what areas ( place them in order)?
- Lacrimal puncta
- Lacrimal canaliculi
- Lacrimal sac
- Nasolacrimal duct
- Nasal cavity
Orbital fat
Cushions and insulates eye
Corneaoscleral junction (corneal limbus)
Border between cornea and sclera.
Where does the ciliary body attach?
Attaches to iris
Ciliary body extends posteriorly to level of what structure?
Ora serrata
Ciliary body contains what structures
- Ciliary muscle
2. ciliary processes
Ciliary zonule attaches the lens to what structure?
ciliary processes
Choroid
Vascular layer that separates fibrous and inner layers posterior to ora serrata and capillaries deliver oxygen and nutrients to retina.
Pupillary muscles
Change diameter of pupil (central opening of eye.
What are the functions of the vascular layer?
- Provides route for blood vessels and lymphatics that supply tissues of eye.
- Regulates amount of light entering eye.
- Secretes and reabsorbs aqueous humor that circulates within chambers of the eye.
- Controls shape of lens, which is essential to focusing.
Pigmented layer
Absorbs light that passes through neural layer.
Neural layer
Contains supporting cells and neurons, outermost part contains photoreceptors.