Special Senses Flashcards
_____ are modified sebaceous glands that produce an oily secretion to lubricate the eye.
Meibomian glands
_____ are modified sweat glands between the eyelashes.
ciliary glands
?
- Membrane that lines the eyelids
- Connects to the surface of the eye
- Secretes mucus to lubricate the eye
conjunctiva
_____ - produces lacrimal fluid
_____ - drains lacrimal fluid from eyes
lacrimal gland
lacrimal canals
_____ - provides passage of lacrimal fluid towards nasal cavity
lacrimal sac
_____ - empties lacrimal fluid into the nasal cavity
nasolacrimal duct
_____ - empties lacrimal fluid into the nasal cavity
nasolacrimal duct
_____ Layer
- Blood-rich nutritive tunic
- Pigment prevents light from scattering
- Modified interiorly into 2 structures
- _____ - smooth muscle
- _____
- pigmented layer that gives eye color
- pupil - round opening of
Choroid
Ciliary body
Iris
Sensory Tunic (_____)
Contains receptor cells (photoreceptors)
- _____ and _____
Signals pass from photoreceptors via a 2-neuron chain
* bipolar neurons and ganglion cells
Signals leave the retina toward the brain through the optic nerve
Retina
rods and cones
Sensory Tunic (_____)
Contains receptor cells (photoreceptors)
- _____ and _____
Signals pass from photoreceptors via a 2-neuron chain
* bipolar neurons and ganglion cells
Signals leave the retina toward the brain through the optic nerve
Retina
rods and cones
Structure of the Eye
Fibrous tunic - _____ layer
_____ - middle layer
_____ - inside layer
outside
choroid
sensory tunic
The Fibrous Tunic
_____
- the white, connective tissue layer
- seen anteriorly as the “white of the eye”
sclera
_____
- transparent, central anterior portion
- allows for light to pass through
- repairs itself easily
- the only human tissue that can be transplanted without fear of rejection
cornea
Neurons of the Retina and Vision
_____
- most are found towards the edges of the retina
- allow dim light vision and peripheral vision
- perception is all in gray tones
rods
_____
- allow for detailed color vision
- densest in the center of the retina
- _____ - the area of the retina with only cones
No photoreceptor cells are at the optic disc, or blind spot
cones
fovea centralis
_____
- allow for detailed color vision
- densest in the center of the retina
- _____ - the area of the retina with only cones
No photoreceptor cells are at the optic disc, or blind spot
cones
fovea centralis
_____
- biconvex, crystal-like structure
- held in place by a suspensory ligament attached to the ciliary body
lens
Internal Eye Chamber Fluids
_____
- watery fluid found in chamber between the lens and cornea
- similar to blood plasma
- helps maintain intraocular pressure
- provides nutrients for the lens and cornea
- reabsorbed into venous blood through the canal of Schlemm
aqueous humor
_____
- gel-like substance behind the lens
- keeps the eye from collapsing
- lasts a lifetime and is not replaced
vitreous humor
The _____ Ear
- Involved in hearing only
external
Bones of the Tympanic Cavity 3 bones span the cavity - \_\_\_\_\_ (hammer) - \_\_\_\_\_ (anvil) - \_\_\_\_\_ (stirrup)
malleus
incus
stapes
Inner Ear or Bony Labyrinth
- Includes sense organs for hearing and balance
- Filled with _____
perilymph
Static Equilibrium
_____ - receptors in the vestibule
* report on the position of the head
* send information via the vestibular nerve
Maculae
Dynamic Equilibrium
_____ - receptors in the semicircular canals
* tuft of hair cells
* cupula (gelatinous cap) covers the hair cells
crista ampullaris
Chemical Senses - Taste and Smell
- Both senses use chemoreceptors
- Stimulated by chemicals in solution
- Taste has 4 types of receptors
- Smell can differentiate a large range of chemicals
- Both senses complement each other and respond to many of the same stimuli
- Olfactory receptors are in the roof of the nasal cavity
- neurons with long cilia
- chemicals must be dissolved in mucus for detection
- Impulses are transmitted via the olfactory nerve
- Interpretation of smells is made in the cortex
