Special Senses - E4 Flashcards
What is..
gustation
olfaction
the vomeronasal organ (VNO)
eating
smelling
phermones
Cell types of gustation areas
all epithelial cells
1. gustatory cells: receptor cells w/short lifespan; have gustatory hairs that protrude into taste pores
- supporting cells
- basal cells: generate new gustatory cells
Dendrites from which CN are in the gustation areas
CN VII, IX, X
synapse at base of gustatory cells
Location of olfaction epithelia
superior nasal septum and concha
Cell types of olfaction areas
- Olfactory sensory neurons
- supporting cells
- olfactory stem cells
olfactory sensory neuron polarity
bipolar
axons from the olfactory neurons form what CN?
CN I-Olfactory
Vomeronasal organ
VNO
2 small, cigar-shaped sacs on either side of nasal septum
receptor cells that are bipolar neurons with microvilli
detect phermones
humans do not have the pathway to utilize this organ
What are..
palpebrae
bulbars
eyelids
eyeballs
Muscles for eyelids
orbicularis oculi - closes
levator palpebrae superioris - opens
conjuctiva
mucous membrane lining the palpebrae and bulbar
lacrimal apparatus
tear production via lacrimal gland
tears drain medially via nasolacrimal duct into nasal cavity
names and cranial nerves associated with the extrinsic eye muscles
- Lateral rectus: VI-Abducens
- Superior oblique & Trochlea: IV-Trochlear
- medial rectus
- superior rectus
- inferior rectus
- inferior oblique
3-6: III-Oculomotor
3 layers of the bulbar from outermost to innermost
- Fibrous layer
- Vascular layer
- Inner Layer
Fibrous layer of the eyeball
Sclera is posterior 5/6; fibrous c.t. maintains focus length
Cornea is anterior 1/6; avascular curvature helps focus light
Vascular layer of the eyeball
Choroid is the dark, vascular membrane lining sclera that absorbs light
Ciliary body is composed of ciliary muscle and ciliary processes
Iris is the anterior colored flap from ciliary body that defines the pupil
ciliary muscle
anterior ring which alters lens thickness for focusing
ciliary processes
vascular projections that secrete aqueous humor
pupillary constrictor
circular muscle (smooth) that makes the pupil smaller in the parasympathetic response
pupillary dilator
radial muscle (myoepithelial cells) that dilate the pupil in the sympathetic response
Innermost layer of the eyeball
AKA nervous layer
known as the retina
lines posterior 2/3
Neural portion of the retina
photoreceptor layer has the rods and cones
ganglion cell layer has the axons from CNII
Rods vs cones
rods are black and white pigments
cones are colored pigments
macula lutea and fovea centralis
pigmented center of the retina
fovea centralis is the depression in center of macula, with the sharpest visual acuity
Optic disc
“blind spot”
point of exit of CN II
anterior and posterior segment of interior eyeball
anterior segment has aqueous humor that is split into anterior chamber (absorbs humor) and posterior chamber (produces humor)
posterior segment has vitreous humor
Ciliary zonule
suspensory ligament that holds the lens in position
Visual pathway to the cerebral cortex
- optic nerves
- optic chiasma
- optic tracts
- thalamus
- cerebrum
2 special senses of the ear
conduction of waves for balance and hearing
Outer ear function
to collect and direct sound waves
Outer ear parts
- Pinna (auricle) - elastic cartilage and skin
2. External acoustic meatus (auditory canal) - skin-lined body tunnel w/hair, ceruminous and sebaceous glands
Middle ear functions
equalize pressure
transfer sound waves to inner ear
Tympanic membrane
ear drum
separates the outer ear from the middle ear
thin partition of fibrous c.t.
ossicles of the middle ear
- malleous (hammer)
- incus (anvil)
- stapes (stirrup)
skeletal muscles of the middle ear
- tensor tympani - tenses tympanic membrane
- stapedius - limits movement of stapes
both help to dampen vibrations
Structures of the inner ear
- Bony labyrinth (petrous portion of temporal bone)
- Membranous labyrinth (fluid-filled) that is w/i the bony labyrinth
- Perilymph is outside of the membranous labyrinth
- Endolymph is inside the membranous labyrinth
These bony labyrinth structures contain what membranous labyrinth structures
- semicircular canals
- vestibule
- cochlea
- semicircular ducts
- utricle and saccule
- cochlear duct
Hairs cells in the ampulla of semicircular ducts are stimulated by _____ and detect _______
changes in rate and direction of movement (angular acceleration)
dynamic equilibrium
Hair cells in the macula of utricle and saccule are stimulated by _____ and detect ______
gravity and linear acceleration
static equilibrium and dynamic equilibrium
Hair cells in the spiral organ of Corti in cochlear duct are stimulated by _______ and detect _______
air vibrations
sound
oval window vs round window
both are thin, bony partitions that separate inner and middle ear
oval window is what the stapes fills
round window dissipates pressure and is covered by the secondary tympanic membrane
Path of sound vibrations
- pinna
- external acoustic meatus
- tympanic membrane
- malleous
- incus
- stapes
- oval window
- bony labyrinth
- membranous labyrinth
- hair receptor cells
- CN VIII - Vestibulocochlear
