Chap 17&18 Flashcards
the conscious or subconscious awareness of changes in the external or internal environment.
sensation
what are the two types of senses
general or somatic or tactile and
special senses
this sense involves touch pressure and vibration
somatic senses
this sense include smell taste
special senses
this sense include thermal sensations like warm and cold
somatic senses
this sense include vision and hearing
special senses
this sense includes balance
special senses
this sense includes pain sensations and proprioceptive like joint and muscle position movements
somatic senses
where are the receptors for your special senses located
in the head in your sensory organs, eyes, mouth, nose, ears
the science of the eye and its disorders
ophthalmology
the science that deals with the ears, nose, and throat and their disorders
otorhinolaryngology
eyebrows, eyelashes, eyelids, and extrinsic eye muscles(move eyeballs) and the lacrimal apparatus (produces tears) are considered what kind of structures
accessory structures
what are the three layers of the eyeball
fibrous tunic
vascular tunic
retina
what does the fibrous tunic include
sclera and cornea
what does the vascular tunic include
choroid, ciliary body, and iris
what does the retina contain
photoreceptors (this is your neural layer)
how many layers does the retina consist of and what are they called
1) neural layer
2) pigmented layer
the photoreceptor layer, bipolar cell layer, and ganglion cell layer are all part of what layer of the retina
neural layer
a sheet of melanin-containing epithelial cells is what layer of the retina
pigmented layer
what divides the interior of the eyeball into two cavities
the lens
what is the name of the two cavities that the lens divides the interior of the eyeball into
the anterior cavity
the vitreous chamber
this cavity is a space between the cornea nd the lens that is filled with watery aqueous humor
the anterior cavity
this cavity is the larger posterior cavity located between the lens and the retina and it contains the vitreous body
vitreous chamber
this watery substance is found in front of the lens and produces intraocular pressure within the eye
aqueous humor
this cavity is filled with a gel like substance and is found behind the lens and helps the eyeball from collapsing and holds the retina flat against the choroid
vitreous body
describe the flow of tears
1) the lacrimal gland found under the eyebrow behind the top outer portion of the eyelid secretes tears into
2) the excretory lacrimal ducts which extend down from the lacrimal gland like little fingers which distribute tears over the surface of the eyeball the tears then flow towards
3) the superior or inferior lacrimal canaliculi which are found in the upper and lower inside corner of the eye which drain the tears into
4) the nasolacrimal duct found in the outside area of the nose on each side between the eyes and cheeks which drains the tears into
5) nasal cavity (causes runny nose when crying)
these are found below the eyebrow under the top portion of the eyelid and secrete tears
lacrimal gland
these are fingers that come off of the lacrimal gland that distribute tears over surface of the eyeball
excretory lacrimal ducts
these are found in a circular area I the corner of the eye that drain tears into the nasolacrimal duct
superior or inferior lacrimal canaliculi
these are found on each side of the nose, extending down from the corner of the eye almost to the end of the nose and drain tears into the nasal cavity
nasolacrimal duct
the colored part of the eye found under the cornea
iris
the tough white part of the eye that forms the majority of the eyeball and is found under the conjunctiva layer
sclera
the black center or hole in the eye found under the cornea that allows light to enter the eyeball and changes size in response to the intensity of light
pupil
the thin protective mucous membrane that covers the anterior eye and folds to cover the inner eyelid.
conjunctiva
what is the pupils response to bright light
the pupil constricts as circular muscles of the iris contract this is a parasympathetic response
what is the pupils response to dim light
the pupil dilates as radial muscles of the iris contract, this is a sympathetic response
what are the two types of photoreceptors
rods and cones
these photoreceptors work best in dim light, they detect different intensities of gray
rods
these photoreceptors work best in bright light, they detect colors and come in three types
cones - red, blue, and green
if you are lacking one or more cones you will have this condition which is more prominent in men
colorblindness
what is the most common cone to be missing in a person with colorblindness
red or green
explain how vision works
refraction of light rays by the cornea and lens, which focus and inverted image on the central fovea of the retina.
what happens when you are viewing close objects
accommodation - the lens increases its curvature and the pupil constricts to prevent light rays from entering the eye through the periphery of the lens
what are the three types of improper refraction
myopia
hyperopia
astigmatism
this is when you can see clearly close up but things far away are blurry
myopia (nearsightedness)
this is when you can see clearly far way but things close up are blurry
hyperopia (farsightedness
this condition is when you have an irregular curvature of the cornea or lens
astigmatism
the movement of the eyeballs towards the nose to view an object is called
convergence (crossing eyes)
an automatic reflex for light rays is called
constriction of pupil
this type of test measures the ability of the lens to focus light on the central fovea
visual acuity tests
this is when the lens changes shape to focus light rays on the central fovea and or lens bulges to focus on objects that are close
accommodation
the closest distance that a person can focus on an object is known as
near point