WEEK 10 SPECIAL SENSORY Flashcards
What is the sclera?
Dense irregular connective tissue
What is the cornea?
Avascular, transparent collagen disc with epithelial covering (bulbar conjunctiva)- it is continuous with the sclera
What is the iris?
Pigmented portion with central pupil
What is the ciliary body?
Smooth muscles that alter lens shape
What is the choroid?
Vascular layer that nourishes retina
What is the retina?
Neurological layer consisting of : Pigmented layer (superficial) and neural layer (deep)
What is myopia?
When the corneal curvature is too steep or axial length of eye too long; light is focused short of the retina (nearsighted)
What is hyperoxia?
Corneal curvature is too flat or axial length of eye too short so image is focused behind the retina (farsighted)
What is antigmatism?
Where there is irregular corneal curvature- light from different axis being brought to focus at different point.
What are treatments for the different forms of sightedness issues?
Laser surgery to change the curvature of the cornea to focus on the retina
Contact lens performs ‘corrected’ corneal surface and focuses image on retina -shifts the curvature
Spectacle lens refracts light rays to focus image on retina
Why do particular movements have to be performed for eye tests to see if muscles/nerves are working?
Because the visual axis is offset from the orbital axis so tension is always placed on the muscles.
What is the action of the superior oblique muscle?
Intort the eye (move towards nose)
What is the action of the inferior olbique muscle?
Extort the eye (move away from nose)
What clinical test can be done to check that the superior oblique muscle is working (trochlear nerve CN IV)?
Look at your nose please
What clinical test can be done to check that the inferior oblique muscle (occulomotor nerve CN III) is working?
Look to the bottom right corner and bottom left corner (for each eye)
What is remote chemoreception?
Olfaction (smell)
What is direct chemoreception?
Taste
What is the main gland for saliva production?
Submandibular gland
What are fuliform papillae?
Dorsal surface of tongue but DO NOT TAKE PLACE IN TASTE
What are the fungiform papillae?
- Broad and flat
- Anterior tip and sides of tongue
- Contain tastebuds (but not majort taste buds)
What are the valate papillae?
Largest of the tastebuds in a V shape of posterior tongue.
- Have densest concentration of tastebuds within papilla
How does facial nerve CN VII transmit taste to the brain?(via what)
The chorda tympani
Which nerve detects taste from the anterior 2/3 of the tongue?
The facial nerve (CN VII) via the chorda tympani (pathway to brain)
What is the physically largest gland?
Parotid gland, enters oral cavity via projecting papilla
Where are the sublingual glands?
Immediately ventral to the tongue and secrete via a series of short sublingual ducts(create a lot of saliva under tongue surface)
Pathway of sound waves:
Waves in external environment–> mechanical signals–> electrical impulses
Where can the signals travel from ear?
Inferior colliculus or medial gmeiculate nucleus
