59 terms

Chapter 8- Special Senses

Smell and Taste are
Chemical senses
What do we sample the environment for?
What does sense of smell cause us to recall?
Why do chemicals detected by our sensory systems need to be volatile?
so they can vaporize reach the nose and dissolve in the mucus
What percent of what we perceive as taste comes from our sense of smell?
What happens when you put food in your mouth?
odor molecules from the food travel in the passage between your nose and mouth to olfactory receptor cells
What happens if the mucus in your nasal passages becomes to thick?
Air and odor molecules cannot reach your olfactory receptor cells.
What is a result of the mucus in your nasal passages becoming to thick?
the brain receives one signal identifying the odor and everything you eat tastes the same
What is another result of the mucus in your nasal passages becoming to thick?
you can feel the temperature and texture of the food but the brain doesnt recognize what it is
How many brain molecules does the brain analyze?
over 300
How many different molecules can a person analyze?
between 4,000 and 10,000
Odors can only be detected in what form?
How do our airborne molecules to our nose?
they combine with receptors in nasal cells
What are cilia?
hairlike receptors that extend from cells inside the nose, are covered with thin clear mucus that dissolves odor molecules not already in vapor form.
What happens when mucus becomes thick?
it no longer liquefies molecules
When is your smell least acute?
in the morning
A womans sense of smell is
greater than a mans
What are taste buds?
found on soft palate pharynx larynx
Where are gustatory receptors located?
on gustatory cells
Where are the taste buds on the tongue located?
What contributes to our sense of taste?
smell temperature and texture
What is the outer ear made of?
pinna, lobe, and external auditory canal
What is the pinna?
thin plate of elastic covered by skin
designed to collect sound waves
External auditory canal
fine hairs
oil glands called ceremonious glands which produce wax
What bones do vibrations hit in the middle ear?
What are bones in the ear called?
What is the main purpose of the middle ear?
to magnify and intensify sound waves
What is the middle ear made up of?
tympanic membrane
What is the inner ear made up of?
semicircular canals
What does the inner ear help the body do?
helps it cope with changes in position, acceleration, and deceleration and not hearing
snail shell appearance
central chamber
Semicircular canals
at right angles to each other allowing each one to be oriented to one of the three planes of space
Why are hearing and equilibrium in the same section?
because both sensations are received in the inner ear
How many branches does the vestibucochlear nerve have?
What is the Vestibular nerve?
carries nerve impulses by equilibrium receptors
What is the Cochlear branch?
nerve that carries nerve impulses by the hearing receptors
What is Conduction deafness?
decreased ability to conduct the energy of sound waves
can be caused by ear wax buildup
What is sensorineural deafness?
caused by damage to hearing receptors, cochlear branch, or damage to the vestibulocochlear nerve
What is static equilibrium?
the position of the head with respect to gravity
What is dynamic equilibrium?
changes in the motion of the head
What is the eustachian tube/auditory tube?
equalizes air pressure on both sides of the ear drum
What do the eyebrows do?
keep sun out of the eye and some sweat
What is the meibomian gland?
ducts at the edges of eyelids which produce oily secretions
What are the ciliary glands?
modified sweat glands
What is conjunctiva?
produce lubricate mucus to keep the eyes from drying out
What is conjunctivitis?
pink eye
What is lacrimal apparatus?
releases a dilute saline solution called tears
What do tears contain?
What do the extrinsic eye muscles do?
produce gross eye movement that allow the eye to follow a moving object
What makes you nearsighted or farsighted?
depends on the curvature of the lens
Why does astigmatism occur?
the cornea is not curved in uniform as a result part of the image is unfocused in the retina
What is glaucoma?
pressure within the eye that increases dramatically when drainage is blocked
What is color blindness?
lacking cones in the eye. Males are more likely to get it
What is cataract?
growth on the cornea, a thin film forms over the cornea
What is the number one cause for cataracts?
UV rays
What is optic chiasma?
fibers cross from each eye to the other
What is aqueous humor?
clear watery fluid
What is the vitreous humor?
gel like substance