Flashcards in general and special senses Deck (48)
Conscious awareness of incoming sensory information is
Stimulus that reaches the cerebral cortex of the brain results in
sensation of that stimulus
Stimuli are detected by
(temperature, pain, touch, stretch, and pressure)
receptors are distributed throughout the skin and organs.
(gustation, olfaction, vision, equilibrium, and hearing)
receptors are housed within complex organs in the head
Range in complexity from single-celled dendritic ending of a neuron to complex sense organs.
Monitor both external and internal conditions and conducts information about those stimuli to the CNS.
precise localization and sensitivity are easily determined.
small receptive field
only detects the general region of the stimulus.
broad receptive field
involved in maintaining our balance to keep our head upright.
signal the increased pressure on our skin
(tune out after a while, acclimation)
which is a reduction in sensitivity to a continually applied stimulus.
receptors in skin or mucous membranes, open to outside of body
receptors located within walls of viscera
receptors in skeletal muscle, tendons, joint capsules
Detect chemicals; specific molecules dissolved in fluid (odor/taste)
Detect changes in temperature
Detect changes in light intensity, color, movement in light rays
Detect physical deformation, (touch, pressure, vibration, stretch)
Detect changes within body structure
Detect tissue damage, pain receptors
gustatory receptors are housed in specialized taste buds on the surface of tongue.
Taste buds lie along sides of epithelial projection (papillae), each bud contains 40 gustatory cells
Works with olfaction
sense of taste
on the anterior 2/3 of the tongue
don’t house taste buds, no sensory role
primarily on the tip and sides
contain only a few taste buds each
(circumvallate): arranged in an inverted V on the posterior dorsal surface
least numerous yet largest, high # of taste buds
each is surrounded by a deep, narrow depression
extend as ridges on posteriolateral sides
house only a few taste buds during childhood, not well developed on the human tongue.
The tongue detects five basic taste sensations:
salty: metal ions (sodium, potassium)
sweet: organic compounds (sugar)
sour: hydrogen ions from acids (lemon)
bitter: alkaloids (brussel sprouts, poisons)
umami: detects amino acids., pleasant taste, chicken-soup
detect odors, bipolar neurons synapse with olfactory bulbs
sandwich the olfactory nerves and sustain and maintain the receptors
function as stem cells to replace olfactory epithelium components
(photoreceptors) in the eyes to detect light, color, and movement.
provide a superficial covering over its anterior exposed surface
prevent foreign objects from coming into contact with eye
Eyebrows, eyelashes, & eyelids
keep the exposed surface moist, clean, and lubricated
Blind spot because no image forms there.
lateral to the optic disc is a rounded, yellowish region of the retina, containing a pit called the fovea centralis (the area of sharpest vision). (contains the highest proportion of cones and almost no rods
space anterior to the lens and posterior to the cornea (aqueous humor)
between the iris and cornea
area behind the lens (vitreous humor)
is between the lens and the iris
maintain shape of eye, thick gelatinous material
removes waste products, fluid
secreted into the posterior chamber, flows around lens, through pupil & into anterior chamber
drains via canal of Schlemm (scleral venous sinus)
processed by the thalamus and then interpreted by visual association areas in the cerebrum.
Visual stimulus information
some axons from the optic nerve decussate.
on each side then contains axons from both eyes.
The optic tract
conducts visual stimulus information
Each optic nerve
External Auditory Canal/Meatus
Function: helps to funnel sounds into canal
Contains an air-filled tympanic cavity.
Medially, a bony wall of the oval window and round window separates the middle ear from the inner ear.
Maintains an open connection with the atmosphere through the auditory tube (Eustachian tube).
Houses the auditory ossicles.
malleus, incus, and stapes
the middle ear
opens into the nasopharynx (upper throat) from the middle ear
air movement through this tube (as a result of chewing, yawning, and swallowing) allows the pressure to equalize on both sides of the tympanic membrane
Receptors sense hearing and equilibrium; housed in fluid-filled tubes/chambers
Membranous labyrinth (endolymph), bony labyrinth (perilymph)
Vestibule, semicircular canals, utricle, saccule, ampulla/cupula, maculae, otolith/statoconia
Cochlea; cochlear, tympanic and vestibular ducts; organ of corti, tectorial membrane
the inner ear