Special Senses Flashcards
the raw input from the peripheral nervous system that arrive at the central nervous system
sensation
the interpretation of the sensations
perception
cells that detect stimuli
sensory receptors
sensory receptors that respond to physical stimuli such as sound and touch
mechanoreceptors
sensory receptors that respond to temperature
thermoreceptors
sensory receptors that detect tissue damage, extreme heat and cold, and chemicals released from damaged cells
pain receptors
sensory receptors that respond to light
photoreceptors
sensory receptors that detect chemicals
chemoreceptors
sensory receptors that detect position of body parts
proprioreceptors
the process by which a sensory receptor converts energy from a stimulus into electrical signals (action potentials)
transduction
a phenomenon in which sensations become less noticeable with prolonged exposure to the stimulus
sensory adaptation
generate fewer action potentials under constant stimulation
the response returns only if the intensity of the stimulus changes
sensory receptors
the __________ __________ detect touch, temperature, or pain with any part of the skin and in the internal organs
general senses
sense organ: skin
stimulus: pressure vibration
type of receptor: mechanoreceptor
touch
sense organ: skin
stimulus: heat, cold
type of receptor: thermoreceptor
temperature
sense organ: everywhere except the brain
stimulus: damage to body tissues
type of receptor: pain receptor
pain
sense organ: joints, muscles, ligaments
stimulus: stretching of muscles and ligaments
type of receptor: proprioceptor
position of body parts
the __________ __________ have specialized structures for vision, olfaction, gustation, hearing, and equilibrium
special senses
sense organ: nasal cavity
stimulus: airborne molecules
type of receptor: chemoreceptor
smell
sense organ: mouth and tongue
stimulus: dissolved molecules
type of receptor: chemoreceptor
taste
sense organ: eyes
stimulus: light
type of receptor: photoreceptor
vision
sense organ: ears
stimulus: air pressure waves
type of receptor: mechanoreceptor
hearing
sense organ: ears
stimulus: motion of fluid in inner ear
type of receptor: mechanoreceptor
equilibrium
elastic movable folds of skin over the eyes, protects the eyes from debris and or trauma
eyelids (palpebrae)
hair that grows at the edge of the eyelids for protection and aesthetics
eyelashes
hairy area of coarse skin above the eye for aesthetics and enhancement of facial expressions
eyebrows
consists of the lacrimal gland and ducts that drain lacrimal secretions into the nasal cavity
lacrimal apparatus
produces tears that cleanses, lubricates and protects the eyes
lacrimal gland
what is the enzyme in tears that destroys bacteria
lysozyme
tears drain to the minute opening called the __________ __________
lacrimal punctum
mucous membrane that lines the eyelids and covers part of the outer surface of the eye
conjunctiva
a thin transparent membrane that covers and protects the anterior portion of the white sclera
bulbar conjunctiva
coats the insides of the eyelids
palpebral conjunctiva
forms the junction between the bulbar and palpebral conjunctivas, loose and flexible, allowing the free movements of the lids and eyeballs
fornix conjunctiva
innervated by the cranial nerves controlling the movement of the eyes
the coordinated action of these allow the eyes to move in tandem, ensuring clear vision
extra-ocular muscles
what are the three cranial nerves that control eye movement
CN III Oculomotor, CN IV Trochlear, and CN VI Abducens
controlled by CN III Oculomotor; elevation, also contributes in abduction and medial rotation of the eyeball (upward)
superior rectus
controlled by CN III Oculomotor; depression, also contributes to adduction and lateral rotation of the eyeball (downward)
inferior rectus
controlled by CN III Oculomotor; adduction (inward)
medial rectus
controlled by CN VI Abducens; abduction (outward)
lateral rectus
controlled by CN IV Trochlear; depresses, abducts and medially rotates the eyeball (downward and outward)
superior oblique
controlled by CN III Oculomotor; elevates, abducts and laterally rotates the eyeball (upward and outward)
inferior oblique
what are the three layers of eye tunics (from superficial to deep)
fibrous layer (sclera & cornea)
vascular tunic (choroid, ciliary body, & iris)
nervous tunic (retina)
outer layer, superficial coat of the eyeball
fibrous layer (tunica fibrosa)
the white coating of the eye, white tough fibrous connective tissue protecting the inner structures of the eye
it helps maintain the shape of the eyeball
sclera
the sclera becomes __________ because of hepatitis
yellow
a modified part of the sclera toward the front of the eye which is a transparent avascular curved window that bends incoming light rays
cornea
also known as the Uvea, middle layer of the eyeball
vascular tunic (tunica vasculosa)
the layer internal to the sclera which is the vascular layer of the eye
choroid
anterior continuation of the choroid that controls the lens’ thickness using its ciliary muscle
with the coordinated actions of the iris’ muscles, it regulates light passing through the lens to the retina
ciliary body
the ciliary body secretes a fluid called __________ __________
aqueous humor
a modified part of the choroid behind the cornea which is the colored part of the eye and regulates the size of the pupil
iris
the hole in the middle of the iris that regulates light entering the eye
pupil
layer of the eyeball that transmits nerve impulses
nervous tunic (tunica nervosa)
a sheet of photoreceptors that forms the innermost layer of the eye
retina
the optic nerve connects to each __________ to the brain
sensory portion of the eye
retina
located near the center of the retina lateral to the optic disk
it is slightly darker than the rest of the retina
macula
it provides the sharpest vision, allowing us to read and recognize faces (central vision)
macula
slight depression within the macula, contains the heaviest concentration of cones and provides the clearest vision and color perception
fovea centralis
a well-defined round or oval area within the retina
the ganglion nerve fibers (axons) exit the retina through this area to form the optic nerve
optic disk
it is a light colored depression within the temporal side of the optic disk where blood vessels enter the retina
physiologic cup
are photoreceptors which are concentrated around the edges of the retina
these cells provide black and white vision in dim light and enable us to see at night (scotopic or night vision)
rod cells
are photoreceptors which are concentrated toward the center of the retina
they require more light and they detect color (photopic or day vision)
cone cells
transparent, flexible tissue located directly behind the iris and the pupil which further bends the incoming light to focus light and images
lens
fluid found between the cornea and the lens that helps bend light rays and focus them on the retina
this fluid cleanses and nourishes the cornea and the lens and maintains that shape of the eyeball
aqueous humor
jellylike substance that fills most of the eyeball’s volume
vitreous humor
it is located right in front of the lens, filled with the aqueous humor, as it flows through the pupil into the anterior chamber, the fluid bathes the lens capsule
posterior chamber
aqueous fluid is manufactured in the __________ __________ by the ciliary body
posterior chamber
the amount of aqueous humor in the __________ __________ varies to maintain the pressure in the eye
anterior chamber
fluid drains from the __________ __________ through collecting channels (trabecular meshwork) into the Schlemm’s canal
anterior chamber
it is a circular lymphatic-like vessel in the eye that collects aqueous humor from the anterior chamber and delivers in into the episcleral blood vessels via aqueous veins
Schlemm’s canal (scleral venous sinus)
the __________ __________ develops during the 1st trimester at the same time as the kidneys and urinary tract
congenital problems may mean a problem in the urinary system
outer ear
shell shaped projecting structure of the external ear that collects and directs sound waves
auricle/earlobe
short and narrow sound passageway that leads from the outer to the inner ear
auditory canal
the ceruminous gland secretes __________
cerumen/earwax
__________ __________ is important when wearing headphones so that you can hear sounds through bone conduction and airwaves
mastoid process
lines the wall of the auditory canal and secretes a waxy yellow substance called ear wax
ceruminous gland
the bony ridge located over the temporal bone and behind the auricle
mastoid process
are thought to protect the delicate structures of the ear, regulate ear pressure and possible protect the temporal bone during trauma
the air filled spaces are important for sound transmission
mastoid air cells
is an air filled cavity which includes the tympanic membrane
it is connected by the Eustachian tube to the nasopharynx and is continuous with the air filled cells in the adjacent mastoid bone
middle ear
a membrane that vibrates in response to sound waves and is the partition between the external auditory canal and the middle ear
ear drum/tympanic membrane
1 mm wide and 35 mm long canal that connects the ear to the nasopharynx
auditory tube/eustachian tube
what are the three smallest bones of the body which amplify the sound and transmit the vibratory motion of the eardrum to the fluids of the inner ear
ossicles (malleus, incus, stapes)
the first bony ossicle where the eardrum is attached
malleus (hammer)
attached to the malleus and stapes
incus (anvil)
attached to the oval window
stapes (stirrups)
two covered openings at the end of the ossicles
it separates the middle ear from the inner ear
windows
window where the vibration enters
oval window
window that is the exit point of vibration
round window
the portion of the ear responsible for balance, equilibrium and hearing housed in the temporal bone
inner ear
it houses the organ of hearing as well as the facial and vestibulocochlear nerves
inner ear
auditory portion of the inner ear filled with fluids which moves in response to the vibrations coming from the middle ear via the oval window stimulating the hair cells
cochlea
found in the space between the membranous and bony labyrinth (tunnels and chambers)
perilymph
found in the membraneous labyrinth
endolymph
sensorineural organ of the cochlea which is composed of hearing receptors called hair cells
organ of corti
specialized sensory cells that change the vibrations into electrical signals that are sent to the brain through the cochlear nerve
hair cells
sensory apparatus of the inner ear that responds to changes in the position of the head with respect to gravity to maintain body balance, signals that are sent to the brain through the vestibular nerve
vestibule (static equilibrium)
sensory apparatus of the inner ear that responds to rotational movements and helping the body maintain postural equilibrium, signals that are sent to the brain through the vestibular nerve
semicircular canal (kinetic or dynamic equilibrium)
sound travels over the air filled external and middle ear through vibration of the tympanic membrane and ossicles
air conduction
sound travels directly through bone to the inner ear bypassing the tympanic membrane and ossicles
bone conduction
__________ __________ is more preferred for cyclists, runners, and swimmers to hear ambient sounds
bone conduction
body balance is maintained by: (4)
muscles/joints (proprioception)
eyes (vision)
ears (vestibular)
cerebellum (cerebellar)
a structure projecting from the face for breathing and smelling
nose
located at the extreme superior region of the nasal cavity that is lined with a specialized epithelium called the olfactory epithelium which contains approximately 10 million olfactory receptor cells
olfactory region
olfactory receptor neurons that are responsible for the detection of odorants which give rise to the sense of smell
olfactory receptor cells
long cilia that protrude from olfactory receptors at the nasal epithelium and are continuously bathed by a layer of mucus
olfactory hairs
the __________ __________ and __________ once stimulated by chemicals dissolved in the mucus will transmit impulses along the olfactory nerve
olfactory receptors and hairs
a neural structure that transmits smell information from the nose to the brain through the olfactory nerve tract
olfactory bulb
what is the medical term for booger
dried nasal mucus
a muscular organ in the mouth that manipulates food mastication and is used in the act of swallowing
tongue
it has importance in the digestive system and is the primary organ of taste in the gustatory system
tongue
are small peglike projections on the dorsal tongue surface that houses the taste buds
papillae
contain the chemoreceptors that detect the flavor of food
taste buds
the receptor cells that make up a taste bud synapse on sensory neurons, which convey the information to the brain
taste buds
are the specific epithelial receptor cells in the taste buds that respond to chemicals dissolved in the saliva
gustatory cells
long microvilli protrusions of gustatory cells that transmit impulses to the brain
gustatory hairs