Anatomy - Ch. 17 Special Senses LECTURE

Olfaction and gustation are ___ senses.

chemical

The human nose contains ___ to ___ receptors for smell (olfaction) in the olfactory epithelium of the superior part of the nasal cavity

10 million -100 million

What 3 cells are involved in olfaction?

1. Olfactory receptor cells

2. Basal cells

3. Supporting cells

Supporting cells (columnar epithelium): located in the ___ ___ lining of the nose.

mucous membrane

Olfaction: [ Supporting cells, basal stem cells, olfactory glands ] are used for physical support, nourishment and electrical insulation for olfactory receptor cells

supporting cells (columnar epithelium)

[ Supporting cells, basal stem cells, olfactory glands ] undergo mitosis to replace olfactory receptor cells

Basal stem cells

[ Supporting cells, basal stem cells, olfactory glands ] produce mucus that is used to dissolve odor molecules so that transduction may occur

olfactory glands

Olfaction: Receptors in the nasal mucosa send impulses along branches of the ____ nerve

olfactory (I)

In olfaction, impulses synapse with the ___ ____ and then travel along the ___ tract.

olfactory bulb, olfactory tract

Where are olfaction impulses/signals interpreted?

In the primary olfactory area in the cerebral cortex (temporal lobe)

Olfaction is the only sensory system that has direct ____ projections without first going through relay stations in the ____.

cortical projections, thalamus

Olfactory sensory pathways (centrally) are [ slowly, rapidly ] adapting, decreasing activity by [ 10, 25, 50, 75 ] % in the first second

rapidly, 50%

How/why do certain odors cause our eyes to tear or noses to run?

The Facial (VII) nerve innervates the olfactory supporting cells/glands which provides parasympathetic motor innervation to the lacrimal glands and mucous membrane.

____ _____ is the process of binding of an odorant molecule

to an olfactory receptor protein

Olfactory Transduction

In olfactory transduction, ____ (___) cause depolarization,

cyclic AMP (cAMP)

In olfactory transduction, an impulse travels to the ___ (lobe) for odor identification.

frontal lobe

What are the 5 primary tastes?

1. sweet

2. salty

3. sour

4. bitter

5. umami (meaty, savory)

Umami is believed to arise from taste receptors that are

stimulated by ___ ___ (___).

monosodium glatamate (MSG)

Approximately [ 10 / 1,000 / 10,000 / 100,000 ] taste buds are found on the tongue of a young adult and on the soft palate, pharynx, and epiglottis

10,000

What 3 types of epithelial cells are located in taste buds?

1. supporting cells

2. basal cells

3. gustatory receptor cells

Taste buds are located in elevations on the tongue

called ___.

papillae

What are the 3 kinds of papillae that contain taste buds?

1. Vallate Papillae

2. Fungiform Papillae

3. Foliate Papillae

What type of papillae DOES NOT contain taste buds?

Filiform papillae

____ papillae - located in lateral trenches of the
tongue (most of their taste buds degenerate in early
childhood)

Foliate papillae

____ papillae - scattered over the tongue with
about 5 taste buds each

Fungiform papillae

___ papillae - about 12 that contain 100–300 taste buds

vallate papillae

____ papillae cover the entire surface of the tongue

filiform papillae

What three cranial nerves are involved in the sense of taste?

1. Facial (VII)

2. Glossopharyngeal (IX)

3. Vagus (X)

We are most sensitive to ___ tastes.

bitter

Complete adaptation to a specific taste can occur in ___ to ___ minutes of continuous stimulation

1-5 minutes

Vision uses visible light which is part of the

electromagnetic spectrum with wavelengths from about

___ to ___nm

400 - 700 nm

What structure is the blind spot for vision?

The optic disc (where the optic nerve exits the eye)

The exact center of the retina is the ___ ___.

macula lutea

What area in the eyeball is the area of highest visual activity?

The fovea centralis

The anterior chamber (between the iris and cornea) is

filled with ____ ____

aqueous humor

The posterior chamber is filled with ___ ___ liquid.

vitreous humor

The ____ admits and refracts light.

cornea

myopia

nearsightedness

A ___ lens is used to correct nearsightedness.

concave

A ___ lens is used to correct farsightedness..

convex

____ occurs when the eyeball is longer than it should be.

myopia (nearsightedness)

____ occurs when the eyeball is shorter than it should be.

hyperopia (farsightedness)

hyperopia

farsightedness

In [ nearsightedness, farsightedness ] the eyeball is shorter than it should be.

farsightedness

____ is a condition where either the cornea or the lens (or both) has an irregular curve and causes blurred or distorted vision

astigmatism

Rods only contain the photoreceptor ____.

rhodopsin

Cones contain ___ different photopigments, one for each of the three types of cones (___, ___, and ___)

3 - red, green, blue

Light adaptation (dark to light) occurs in ____.

seconds

Dark adaptation (light to dark) takes ____.

minutes

The different times for light adaptation and dark adaption is due to the rates of ___ and ___ of photopigments in rods and cones.

bleaching, regeneration

Light causes rod photoreceptors to decrease their release of the inhibitory neurotransmitter ___.

glutamate

Night blindness is due to the inability to make a normal amount of ___.

rhodopsin

Color blindness is due to the absence of certain ___ photopigments.

cone

Night blindness is possibly due to the deficiency of vitamin __.

A

What is the pathway for vision?

optic chiasm → optic tract → lateral geniculate nucleus of the thalamus → info is sent/processed in occipital lobes for perception

In conversion (vision), ___ cone cell synapses onto one bipolar cell

1

In conversion (vision), ___ rod cells synapse on a singular bipolar cell

600

In conversion (vision), ___ (#) photoreceptor cells converge into ___ (#) ganglion cells.

126 million photoreceptor cells, 1 million ganglion cells

What 3 regions is the ear divided into?

1. external ear

2. middle ear

3. internal ear

The transduction of sound vibrations by the ear’s
sensory receptors into electrical signals are ___ times
faster than the response to light by the eye’s
photoreceptors

1,000

What structures make up the external ear? (3)

1. Auricle

2. External auditory canal

3. Tympanic membrane (eardrum)

The middle ear contains __ auditory ossicles (smallest bones in body).

3

What are the 3 auditory ossicles?

malleus, incus, stapes

The auditory ossicles help to transmit sound vibrations from the ___ to the ___ ___.

eardrum, oval window

What structure helps to regulate air pressure in the middle ear?

The auditory tube

The internal ear contains the ___ (structure) that translates vibrations into neural impulses that the brain can interpret as sound.

cochlea

The ___ ___ works with the ___ for balance and equilibrium.

semicircular canals, cerebellum

sounds heard best = ___-___ Hertz; range = ___ to ___

Hz (cps)

1,000-4,000 ; 20-20,000

Frequency of a sound vibration = ____

pitch

Speech is ___ to ___ Hz

100 - 300 Hz

What unit is used to measure sound?

decibels (dB)

What unit is used to measure sound waves?

Hertz (Hz)

Conversation = ___ dB

60

Pain = above __ dB

140

slide #74