Special Senses Part One (smell, taste, vision, hearing) Flashcards
What is the special apparatus for olfaction and gustation? Cranial nerves for each?
Chemoreception
Olfaction: CN 1
Gustation: CN 7, 9, 10
What is the special apparatus for vision? Cranial nerves?
Photoreception
CN 2
What is the special sense in cranial nerve 10?
Taste (in the epiglottis!)
Cranial nerves for…
Extra-ocular muscles:
Intra-ocular muscles:
Extra-ocular muscles: CN 3, 4, 6
Intra-ocular muscles: CN 3
The intra-ocular muscles are innervated by what kind of fibers?
Sympathetic postganglionic
What is the special apparatus for audition and equilibrium? Cranial nerves?
Mechanoreception
CN 8
Olfaction…
The nerves have receptors on their surfaces and chemicals bind to it; if the stimulus is large enough, what happens?
You get a big enough graded potential then you generate an action potential
Olfactory nerve is an extension of…?
the brain
All the nerves going to the olfactory bulb are derived from where?
The olfactory placode
All the nerve fibers are buried in what part of the nasal cavity?
the epithelium that lines the nasal cavity
In the olfactory epithelia…
What is the name of the basal lamina?
It contains the what?
Lamina propria
Contains olfactory glands
The olfactory receptor cells are derived from what?
olfactory placode
What is actually covered with the receptors?
The olfactory cilia
What differentiates into epithelium itself?
Basal cells
What makes up the bulk of the epithelium?
Support cells
Epithelium can also differentiate into what?
Glands to secrete stuff
In the glands, a certain protein is secretes and binds to water and becomes what?
Mucus
the odorant molecules need the stickiness to dissolve and bind to receptors
Olfactory receptor cells have terminal knobs that project where?
What covers those knobs?
at the apex of the epithelial layer
covered with cilia
Do olfactory receptor cells have myelin? Why or why not?
No, because the myelin would be a barrier to binding to the odorant
The odorants that get dissolved bind to proteins on the surfaces of what?
Olfactory cilia
Circumvallate papillae have taste buds and the taste buds have taste pores that “open” to what?
The cleft in the papillae
The taste pores allow material to access what?
Gustatory cells
What kind of cells only live for about 10 days?
Gustatory cells
The molecules get carried down into the cleft after they have been dissolved in what?
Saliva
What are the 4 primary tastes? 2 “additional” taste sensations?
Sweet, salty, sour, bitter
Umami, Water
The umami sensation has receptors primarily for what amino acid?
Glutamate
The sensation for water is spread throughout what? What is it connected to?
Spread throughout the brain
Connected to the brain and water balance system
What is the “spicy” sensation? Cranial nerves associated with it?
Pain signals carried by CN V3 and CN 9
In the rostral 2/3 of the tongue, what is the CN for…
General sensation:
Special senses:
General: CN V3
Special (taste): CN 7
What is the pupil?
The dark portion (hole) that allows light to enter
What is the iris?
The colorful area surrounding the pupil
has pigmentation
What is the sclera?
The white, dense fibrous connective tissue
maintains structure
What overlies the pupil and the iris?
The cornea
What is the lateral commissure/canthus?
The lateral “corner” of the eye
What is the medial commissure/canthus?
The medial “corner” of the eye
What is the name of the “bunk” in the medial aspect?
Lacrimal caruncle
Only the dorsal lateral area of the eye contains what gland?
Lacrimal gland
What comes off the lacrimal gland and into eyelid?
Lacrimal ducts
What connects the nasolacrimal duct to the lacrimal caruncle?
Lacrimal canaliculi
What is the name of the “holes” of the lacrimal canaliculi?
Lacrimal puncta
Explain the pathway of tears.
Tears are created in lacrimal glands and are secreted through lacrimal ducts
Tears go onto dorsal lateral surface of the eye
When you blind, the tears are pushed across the eye into the lacrimal “lake”
Tears enter through lacrimal puncta, go into lacrimal canaliculi, and go into the nasolacrimal duct
When you produce an excess of tears, the tears eventually get into your…
Nasal cavity
What muscle relaxes when you blink then contacts when you lift your eyelid?
What cranial nerve?
levator palpebrae superioris
CN 3
What extrinsic eye muscles does the (motor) Oculomotor nerve go to?
Superior rectus
Inferior rectus
Medial rectus
Inferior oblique
What does the (parasympathetic preganglionic) Oculomotor nerve go to?
Where do they synapse?
Sphincter pupillae
Ciliaris muscle
Synapse in ciliary ganglion
The oculomotor nerve also carries postganglionic sympathetic innervation to the eye, but where did the preganglionic sympathetic innervation come from? Where did it synapse?
Then where does it go?
the thorax to the sympathetic trunk (chain) up to the superior cervical ganglion where it synapses
Goes through the carotid canal to the oculomotor nerve and it carried to the eye
Where is one of the places that the postganglionic SYMPATHETIC fibers go in the eye that is “opposite” of where the parasympathetic fibers go?
Pupillary dilator
