Chapter 3 F - special senses Flashcards
The general senses refer to both somatic senses and visceral senses:
- Somatic senses: include X sensations (touch, pressure, vibration, itch, and
tickle), X sensations (warm and cold), X sensations, and X
sensations. X sensations allow perception of both the static
(nonmoving) positions of limbs and body parts (joint and muscle position sense)
and movements of the limbs and head.
X tactile
X thermal
X pain
X proprioceptive
X proprioceptive
The general senses refer to both somatic senses and visceral senses:
- Visceral senses: provide information about conditions X, for
example, pressure, stretch, chemicals, nausea, hunger, and temperature.
within internal organs
The special senses include the sensory
modalities of smell, X, vision, X, and
equilibrium or balance
taste
hearing
Receptors for the special senses (smell, taste, vision, hearing, and equilibrium)
are anatomically similar to one another and are concentrated in specific
locations in the head.
true/false
false:
they are distinct
Special senses receptors are usually embedded in the epithelial tissue within complex sensory organs
such as the eyes and ears.
True/false
true
Neural pathways for the special senses are more complex than those for the
general senses.
true/false
true
The receptors for the sense of smell or olfaction are located in the X
of the nose.
olfactory epithelium
Olfactory receptor cells are the X neurons of the olfactory
pathway.
firstorder
Olfactory receptor cells contain olfactory receptor
X that detect inhaled chemicals
(odorant molecules).
proteins
Olfactory transduction:
olfactory
receptor cells respond to the chemical
stimulation of an odorant molecule by
producing a receptor X that triggers one or
more nerve impulses.
potential
(depolarization)
Bundles of axons of olfactory receptor
cells form the right and left olfactory
(I) X
nerves
Axons of olfactory receptor cells (first order neurons) converge onto X
neurons (mitral cells) forming the olfactory tract
second order
Some of the axons of the olfactory tract project to the primary olfactory area in the
X (temporal lobe), where X of smell occurs.
- Others project to the limbic system. These neural connections account for our X
responses to odors
cerebral cortex
conscious awareness
emotional
Peculiarities of the olfactory pathway:
- Unlike other sensory pathways, it consists of only one/two/three neuron(s).
- Furthermore, olfactory sensations are the only ones that reach the olfactory cortex
without first synapsing in the X..
two
thalamus
The receptors for sensations of taste are located in the taste buds, which are located in
elevations on the tongue called papillae.
- Taste buds contain X that project microvilli (gustatory hairs) to
the external surface. - X synapse with dendrites of the X neurons that form the
first part of the gustatory pathway.
gustatory receptor cells
Gustatory receptor cells
first-order
Taste transduction occurs in gustatory receptor cells: chemicals from food (tastants)
stimulate gustatory receptor cells causing a X receptor potential that
stimulates exocytosis of synaptic vesicles from the gustatory receptor cell.
depolarizing
- Neurotransmitter molecules liberated from
gustatory receptor cells trigger graded
potentials that may produce X
in the X sensory neurons that
synapse with gustatory receptor cells
nerve impulses
first-order
The dendrites of each first-order neuron
branch profusely and contact one/a few/many
gustatory receptor cells in several taste
buds.
many
From the taste buds, nerve impulses
propagate along X nerves (VII, IX and X)
to the gustatory nucleus in the medulla
oblongata (brainstem).
From the medulla, some axons carrying taste
signals project to the X system and the
hypothalamus and others project to the
X.
cranial
limbic (=zoogdierbrein)
thalamus
Taste signals that project from the thalamus to
the X in the cerebral
cortex give rise to the conscious perception of
taste and discrimination of taste sensations.
primary gustatory area
Photoreceptor cell (X and X) are located at the retina (inner tunic of the eyeball).
- Photoreceptor cells contain photopigments that undergo structural changes when
absorbing light
rods and cones
Phototransduction is the
process by which light energy
is converted into a X in the outer
segment of a photoreceptor.
receptor
potential
Activation of a photoreceptor
by light causes a
depolarizing receptor
potential.
true/false
hyperpolarizing
phototransduction: In this situation, the nerve
cells (ganglion cells) that form
the X (II) nerve are
stimulated.
optic
The axons of the retinal ganglion cells form the optic (II) nerve which provide output
from the retina to the brain
true/false
true
The arrival of action potentials in the primary visual area of the cerebral cortex allows
you to perceive shades.
true/false
false: allows you to perceive light
The spiral organ or organ of X is
a specialized sensory epithelium that
allows for the transduction of X into neural signals. It is
located within the cochlea.
Corti
sound
vibrations
- The organ of Corti is a coiled sheet of epithelial cells that includes X cells:
hair
The organ of Corti is a coiled sheet of epithelial cells that includes hair cells:
- Inner hair cells are arranged in three rows/in a single row: convert the mechanical vibrations of
sound (bending of the stereocilia) into electrical signals (generation of nerve
impulse). - Outer hair cells are arranged in one row/three rows: increase the sensitivity of the inner hair
cells.
Inner: one row
Outer: three rows
From cochlear branch of the vestibulocochlear (VIII) nerve, auditory information is
conveyed to the X, thalamus, and X in cerebral cortex.
brainstem
primary auditory area
Since many auditory axons decussate (cross over) at the pons while others remain on the
same side, the right and left primary auditory areas receive nerve impulses from one ear/both
ears.
both
Body movements that stimulate the receptors for X include:
- Linear acceleration or deceleration
- Tilting the head forward or backward
- Rotational (angular) acceleration or deceleration
equilibrium
Collectively, the receptor organs for equilibrium are called the X
vestibular apparatus.
Receptor organs of the vestibular apparatus include:
* Utricle and saccule of the vestibule (otolithic organs): dynamic/static equilibrium
* Semicircular ducts of the semicircular canals: dynamic/static equilibrium
- static
- dynamic
Attached to the inner walls of both the utricle and the saccule is a small, thickened
region called the macula.
true/false
true
The maculae consist of two types of cells:
1. cells: sensory receptors
2. X supporting cells: probably secrete the thick, gelatinous, glycoprotein
layer (otolithic membrane), that rests on the hair cells
Hair cells
Columnar
A layer of dense calcium
carbonate crystals, called
X extends over the
entire surface of the
X membrane.
otoliths
otolithic
Because the otolithic membrane sits on top of the macula, if you tilt your head forward,
the otolithic membrane (along with the otoliths) is pulled by gravity.
* It slides “downhill” over the hair cells in the direction of the tilt, bending the hair bundles
true/false
true
Bending of the hair bundles in the utricle or saccule, but not in the semicircular canals, causes the release of a neurotransmitter which generates nerve
impulses in the sensory neurons that innervate the hair cells
true or false
false: also in the semicircular canals
The hair cells synapse with
X sensory neurons of
the vestibular branch of the
X (VIII) nerve.
first-order
vestibulocochlear
Crista in the ampulla of semicircular duct consists of a group of hair cells and
supporting cells.
* Covering the crista is a mass of gelatinous material called the X
cupula
Bending of the hair bundles in the semicircular canals causes the release of a
neurotransmitter which generates nerve impulses in the sensory neurons that
innervate the hair cells.
gracias
From hair cells of the semicircular ducts, utricle, and saccule, vestibular information
is conveyed along the vestibular branch of the X (VIII) nerve and
then to the brainstem, cerebellum, thalamus, and the vestibular area in cerebral
cortex.
vestibulocochlear
The vestibular area in cerebral cortex is part of the primary somatosensory area to
provide us with the conscious awareness of the position and movements of the head
and limbs.
true/false
true
