Chapter 9: Senses Flashcards
process initiated by stimulating sensory receptors
Sensation
receptors distributed over a large part of the body
General Senses
Provide sensory information about the body and the environment
Somatic Senses
provide information about internal organs, mainly pain and pressure
Visceral Senses
sensory nerve endings or specialized cells capable of responding to stimuli by developing action potentials
Sensory Receptors
Types of Sensory Receptors
- Mechanoreceptors
- Chemoreceptors
- Photoreceptors
- Thermoreceptors
- Nociceptors
sensory receptors that respond to temperature changes
Thermoreceptors
Sensory receptor that respond to stimuli that result in the sensation of pain
Nociceptors
sensory receptor that respond to mechanical stimuli
Mechanoreceptors
sensory receptor that respond to chemicals
Chemoreceptors
sensory receptor that respond to light
Photoreceptor
Type of sensory receptor thay consists of specialized cells that detect diff odor molecules present in the air
Olfactory Receptors
responsible for processing and interpreting information about different smells detected by our olfactory receptors in the nose
Olfactory Bulb
bundle of nerve fibers that connects the olfactory bulb to other regions of the brain, specifically the primary olfactory cortex
Olfactory Tract
primary means by which the sense of smell is transmitted to the CNS
Olfactory Nerves
sensory receptor responsible for sense of hearing
Hair cells
responsible for converting sound vibrations into electrical signals that can be interpreted by the brain
Cochlea
bundle of nerve fibers that carries auditory information from cochlea to the brain
Auditory Nerve
primary area responsible for processing auditory information including the perception and interpretation of sounds
Auditory Cortex
specialized in detecting mechanical stimuli such as pressure, touch, vibration, and stretch
Mechanoreceptors
sensitive to light touch and low-frequency vibrations
Meissner’s corpuscles
respond to sustained pressure and play a role in the perception of shapes and edges
Merkel Discs
Mechanoreceptors that are sensitive to rapid changes in pressure or vibration
Pacinian Corpuscles
Respond to sustained pressure and stretching of skin
Ruffini Corpuscles
responsible for our sense of taste allowing us to perceive and distinguish diff flavors
Taste Buds
key players in taste process
taste receptor cells
taste receptor cells have microscopic hair-like projections called __ __ or __
taste hairs or microvilli
Taste hairs or microvilli extend into a small opening called __ __
taste pore
sense of movement and position of the body and limbs
proprioception
simplest and most common receptors which are relatively unspecialized neuronal branches similar to dendrites
free nerve endings
- structurally more complex than free nerve endings
- many are enclosed by capsules
touch receptors
types of touch receptors
- merkel disks
- hair follicle receptors
- meissner corpuscles
- ruffini corpuscles
- pacinian corpuscles
- characterized by a group of unpleasant perceptual and emotional experiences
- serves as one of the paramount signals our body provides to ensure our survival
pain
2 types of pain sensation
- localized, sharp, pricking, or cutting pain
- diffuse, burning, or aching pain
resulting from rapidly conducted action potentials
localized, sharp, prickling, or cutting pain
resulting from action potentials that are propagated more slowly
diffuse, burning, or aching pain
use of medicines to prevent pain during surgery and other procedures
anesthesia
anesthesia may be given through:
- injection
- inhalation
- topical lotion
- spray
- eye drops
- skin patch
types of anesthesia
- local anesthesia
- general anesthesia
a treatment where chemical anesthetics are injected near a sensory receptor or nerve, resulting in reduced pain sensation
local anesthesia
a treatment where chemical anesthetics that affect the reticular formation are administered
general anesthesia
proposes the existence of neurological ‘gate’ within the spinal cord that regulates the transmission of pain signals to the brain
gate control theory
- closely related, both structurally and functionally
- both are initiated by the interaction of chemicals with sensory receptors
smell and taste
initiated by the interaction of light with sensory receptors
vision
occurs in response to sound waves
hearing
occurs in response to gravity or motion
balance
sense of smell which occurs in response to airborne molecules called odorants that enter the nasal cavity
olfaction
bipolar neurons within the olfactory epithelium which lines the superior part of the nasal cavity
olfactory neurons
supporting the head’s structures and protecting the brain, including the eyes and nasal passages
frontal bones
- first cranial nerve
- enables the sense of taste
fibers olfactory nerve
transmits the olfactory nerves that carry the sense of smell
cribriform plate of ethmoid bone
- warms and humidifies the air as you breathe
- acts as a barrier for the immune system to keep harmful microbes from entering the body
nasal cavity
- connect your nasal passages to the rest of your respiratory system
- allows air to get from your nose to your lungs
nasopharynx
involved with feeding, breathing, swallowing, and speech
palate
- thin, clear liquid consisting of water, salts, and protective immune cells
- protects the tissue that lines your lungs, throat, and nasal and sinus passages and keeps them from drying out
mucus
accessory structures (vision)
- eyebrows
- eyelids
- conjunctiva
- lacrimal apparatus
- extrinsic eye muscles
prevent perspiration and direct sunlight from entering the eyes
eyebrows
- lined with eyelashes
- protects the eye from foreign objects
eyelids
thin, transparent mucus membrane, covering the inner surface of the eyelids and the eye’s anterior surface
conjunctiva
produces tears
lacrimal gland
collects tears
lacrimal canaliculi
opening to nasal cavity
lacrimal sac
enables the movement of the eyeball
extrinsic eye muscles
hollow, fluid-filled sphere
eyeball
3 tissue layers or tunics of the eyeball’s wall
- fibrous tunic
- vascular tunic
- nervous tunic
outer and black part of the eye
fibrous tunic
middle layer
vascular tunic
inner and colored part of the eye
nervous tunic
chambers of the eye
- anterior chamber
- posterior chamber
- vitreous chamber
- filled with aqueous humor
- help maintain pressure, refracts light, and provide nutrients to inner surface of eye
anterior chamber
contains aqueous humor
posterior chamber
- filled with vitreous humor
- help maintain pressure, hold lens and retina in place, refracts light
vitreous chamber
leaves eye and exits orbit through optic foramen to enter cranial cavity
optic nerve
where 2 optic nerves connect
optic chiasm
route of ganglion axons to the thalamus
optic tracts
extend from the thalamus to the visual cortex in the occipital lobe
optic radiations
nearsightedness
myopia
farsightedness
hyperopia
lens becomes less elastic
presbyopia
irregular curvature of lens
astigmatism
absence or deficient cones
colorblindness
increased pressure in eye
glaucoma
part extending from the outside of the head to the tympanic membrane
external ear
- fleshy part of the external ear on the outside of the head
- opens into the external auditory canal
auricle
lined with hairs and ceruminous (wax) glands, which produce cerumen (earwax)
auditory canal
- eardrum
- thin membrane that separates the external ear from the middle ear
tympanic membrane
air-filled chamber medial to the tympanic membrane
middle ear
3 auditory ossicles of the middle ear
- malleus (hammer)
- incus (anvil)
- stapes (stirrup)
consists of interconnecting tunnels and chambers within the temporal bone
inner ear
involved in balance
- vestibule
- semicircular canals
create sound waves
vibrations
collected by the auricle and conducted through the external auditory canal toward the tympanic membrane
sound waves
2 components of equilibrium
- static equilibrium
- dynamic equilibrium
associated with the vestibule and is involved in evaluating the position of the head relative to gravity
static equilibrium
associated with the semicircular canals and is involved in evaluating changes in the direction and rate of head movements
dynamic equilibrium
mechanical deficiency in transmission of sound waves from outer ear to spiral organ
conduction deafness
deficiencies of spiral organ or nerve pathways
sensorineural hearing loss
phantom sound sensations such as ringing in ears
tinnitus
can damage or rupture tympanic membrane in extreme cases
middle ear infection
- can decrease detection of sound and maintenance of balance
- may be caused by chronic middle ear infections
inner ear infection
caused when information to brain from semicircular canals conflicts with the information from eyes and position sensors in back and lower limbs
nausea
- vertigo, hearing loss, tinnitus, and a feeling of fullness in the affected ear
- most common disease involving dizziness from inner ear
meniere disease
