Synesthesia
a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway
Somatic (general) Senses
receptors found throughout the body including joints and organs
Special Senses
specialized receptors found in the head (sight, smell, sound, taste)
Sensation
feeling that occurs when a brain interprets a sensory nerve impulse
Projection
the brain causes a feeling to stem from a source
Sensory adaptation
sensory receptors stop sending signals when they are repeatedly stimulated
Receptor cells in the PNS are activated by …
stimuli in the environment
What are the three different criterias for receptor cells?
cell type, position, function
Free nerve endings
dendrites embedded in tissue as receivers which respond to pain and temperature
Encapsulated
embedded in connective tissue to increase sensitivity (pressure and touch)
Specialized
receptors in the retina of the eye
Exteroceptor
located near external environment (skin)
Interoceptor
interprets stimuli from internal organs
Proprioceptor
located near moving body parts, interprets position
Chemoreceptor
chemicals, mostly found in nose/mouth
Photoreceptor
light
Osmoreceptor
respond to solutes in body fluids
Thermoreceptor
temperature
Mechanoreceptor
pressure, vibration, body position, movement
Visceral pain
occurs in visceral tissues such as heart, lungs, intestine
Referred pain
feels as though it is coming from a different part
Acute pain
originates from skin, usually stops when stimulus stops
Chronic pain
dull aching pain
FLACC
Face, Legs, Activity, Cry, Consolability Scale
Overview of how opioids work
nerve sends signals
opioids slow/block signal
limbic system (emotional) and reward pathway are stimulated
Special Senses
Olfactory, Gustatory, Hearing and Equilibrium
Olfactory
odor
receptor cell
olfactory bulb
olfactory tract
Gustatory
papillae (taste buds)
Taste sensations
sweet
salty
bitter
sour
savory
Umami
A savory taste →mixture of 2 or more tatse
Genetics play a role in
whether you like certain foods
Auricle (pinna)
outer ear
Auditory canal
ear canal
Auriculares
responsible for ear movement
Ear wiggling is considered
vestigial trait
Vestigial Trait
a trait that no longer functions but is part of our evolutionary past
Middle ear
tympanic cavity
Eardrum
tympanum
Auditory Ossicles
malleus, incus, stapes
The malleus, incus, and stapes transmit …
vibrations and amplify the signal
Auditory Tube (Eustachian tube)
connects the middle ear to the throat →helps maintain air pressure
Labyrinth
communicating chambers and tubes
Semicircular canals
sense of equilibrium
Cochlea
snail shaped, sense of hearing
Organ of Corti
contains hearing receptors, hair cells detect vibrations
Loud noises can damage the …
hair cells located in the cochlea
Tinnitus
ringing in the ear
Static equilibrum
maintain stability and posture
Dynamic equilibrum
balance during sudden movement
Cerebellum
interprets impulses from the semicircular canals and maintains overall balance
Otolaryngology
study of ear, nose, and throat
Anosmia
no smell
Anhidrosis
inability to sweat
Congenital Analgesia (CIP)
feel no pain
Syndrome
disease that has more than one feature or symptom
Usher syndrome can also cause …
vision problems
Deafness can also be caused by …
prenatal infections
Prenatal infections
toxoplasmosis
rubella
cytomegalovirus
herpes
Postnatal infections
meningitis
streptococcus
influenza
listeria
Prebycusis
age related hearing loss
Eyelid
covers and protects the eye, thin skin will not protect you from intense radiation
Eyelashes
fine hair that function to protect the eyes from dust and debris
Trichiasis
inversion of the eyelashes, which can irritate the eye
Conjunctiva
a covering around the eye and under the eyelids
Pink eye
conjunctivitis
Extrinsic eye muscles
superior rectus - inferior rectus
medial rectus - later rectus
superior oblique - inferior oblique
Lacrimal glands
produce tears, which drain into the nasal cavity via the lacrimal duct
Tears function to …
moisten and lubricate the eye surface, and it has enzymes that kill bacteria
Cornea
transparent dome that focuses light
Sclera
continuation of cornea, going toward the back of the eye (white part)
Optic nerve
exits at optic disk and transmits information from the eye to occipital lobe of the brain
Optic neuritis
sudden vision loss
Choroid
contains blood vessels
Ciliary body
holds the lens in place
Lens
focusing
Iris
colored portion of the eye
Pupil
opening for light to enter
Aqueous humor
liquid surrounding the lens
Melanin
browish pigment that adds color to your hair, eyes, and skin
Heterochromia
one eye is a different color than the other
Pupils
dilate or constrict to adjust light entering eye
Red eye
light reflecting off the retina
Retina
visual receptor cells
Fovea centralis
region of the sharpest vision, also called macula
Optic disk
where nerve fibers leave eye creating a blind spot
Vitreous humor
supports internal parts, fluid within the eye
Blind spot
the region where the optic nerve and bloods vessels meet. Has no photoreceptors
Photoreceptors in the retina are
sensors for light
Rods
monochromatic (black and white)
Cones
color vision
Accommodation
lens change shape to facilitate focusing
Images are projected to the back of the eye and then …
the lens reverses the image
Zonules of Zinn
connect ciliary body to lens
can change the shape of the lens
also called suspensory ligament
Cataracts
clouding of the eye
Aniridia
a condition where a person is born without an iris
Onchocerciasis
river blindness →disease caused by infection by a parasitic worm
Color blindness
genetic trait that effect boys more than girls
Floaters
occur when the vitreous substance clumps and casts shadows on the retina
Retinsl detachment
occurs ehrn the retina is pulled away from its normal position
Glaucoma
pressure from vitreous humor damages the optic nerve and can lead to blindness