Transcript File


Once the dopamine is dropping due to the
hypothalamic and adrenal dopaminenorepinephrine conversion, followed by
oxytocin, the pituitary gland starts releases
another hormone called prolactin which turns
norepinephrine into the sympathetic nervous
adrenergic alpha receptors of the penile,
urethral and prostate arteries for constriction
and into the sympathetic nervous fire for
induction of prostaglandin E2 release, ready
for ejaculation; and then, you experience
sympathetic nervous Fight or Flight, where Fight
= Premature Ejaculation
The role of sensory receptors
Assessing sensory input
Sensation vs perception
Sensory neurons: detect changes in the
___________and ____________environment
 Types of sensory receptors:

› __________________________________
› ____________________________________
› _________________________________
› ___________________________________
› ____________________________________
Animals monitor the external environment
differently depending on their __________
and _______________of sensory receptors.
 Some animals have sensory receptors that
we lack.

› Some animals have sensory receptors that allow
them to detect ___________________________
› Others simply have _________________receptors
than we do.
› Honeybees can detect __________ and _________
radiation, whereas we detect only visible light.

The brain uses three variables to
determine the location and intensity of a
stimulus
› Nerve that delivers the action potentials
 ____________________________________
› Frequency of action potentials
 _____________________________________
› Number of sensory receptors firing
 _______________________________________

Sensory adaptation: sensory neurons
cease firing in spite of
_______________________________________
› Walk into a house where an apple pie is
baking and you notice the sweet scent of
baking apples immediately.
› Within a few minutes,
__________________________________________
› The odor does not change in intensity, but
_________________ in your nose undergo
sensory adaptation.
Sensation: _____________________________
 Perception: ___________________________
________________

Somatic and visceral sensation
Pain and pain relief
General senses involve action of receptors throughout the body
By contrast, special senses arise from receptors located in specific
sensory organs, such as eyes or ears

Somatic sensations: arise from sensory neuron
receptor endings in _____or ________________, or
________________
› Example: heat and cold arise from thermoreceptors
in skin


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Signals involved in somatic sensation travel
through the spine to the _____________________.
As in the motor cortex (Chapter 29), neurons in
the somatosensory cortex are arrayed like a
_______________________________.
As a result of this organization, somatic
sensations are easily localized to a specific
region of the body; it is easy for you to say
exactly _____________________________________.

Body parts that
appear
disproportionately
large in this diagram
(such as fingertips
and face) have the
_____________________
_____________________
_____________________

Visceral sensations: arise from sensory
receptors in the walls of ________________
› Example: feeling of full bladder arises from
______________________________

Signals from neurons involved in visceral
sensations do not map onto the cortex in
a region-specific fashion as somatic
signals do. So visceral sensations are not
as easily localized as somatic ones.
_______________________________________
_______________________________________

Pain: perception of ____________________
› Injured body cells release ______________and
________________that activate pain receptors
› Action potential travels to ________________
› Endorphins: __________interneurondependent pain perception (doesn’t send
signal to brain)
› Substance P: __________interneurondependent pain perception (makes neurons
send signal to brain)
Sense of smell
Sense of taste
Allows animals to detect _____, _______,
or _________, and helps them identify
_______________
 Olfactory receptors: respond to
___________________in the air or water
that surrounds it
 Most invertebrates sense the world
around them primarily through smell
 Vertebrates have olfactory receptors in
the lining of their _______________________


Animals produce and detect pheromones:
› _______________communication signals that are
secreted by one indiv and alter the behavior of
another member of its spp.
› For example, a female silk moth releases a sex
pheromone that a male silk moth can detect
from as far as a km away. The male has
receptors for the pheromone on his antennae.
› In land vertebrates, pheromone receptors are
typically clustered in a ___________________
organ at the base of the nasal cavity.
› Humans have a reduced version of this organ.
Whether we make and respond to pheromones
remains a matter of debate.
Helps animals avoid _________and
detect appropriate ____________items
 Taste receptor: ________________________
 Taste buds are in upper surface of the
tongue
 Sensory organs are located in
specialized epithelial structures, called
_________________________

Perceived taste arises from a
combination of signals
 Humans can taste:

› Sweetness (_______________________________)
› Sourness (_____________)
› Saltiness (_________________________________)
› Umami (__________________)
› Fattiness (_________________)
Diversity of visual systems
Anatomy of the human eye
Focusing mechanisms

Vision: detection of _______in a way that provides
a __________image of objects in the environment
› Requires eyes (sensory organs with __________________)
with a ___________
› And a ___________that can interpret visual stimuli

Insects have compound eyes
› ____________________________________________________

Cephalopod mollusks (octopi) have camera
eyes
› Eye with an adjustable opening and a ___________that
focuses light on a ___________(innermost membrane)
A human eyeball sits in a protective,
cuplike, bony cavity called the ________.
 ________________that run from the rear of
the eye to bones of the orbit move the
eyeball.
 _______, __________, and _______protect
the eye tissues.
 Periodic blinking _______________________
_______________________________________.

Light rays reflected from near and distant
objects hit the eye _____________________
 Visual accommodation: ciliary muscles
adjust the shape of the _______so all rays
become focused on ____________
 Flat lens: _______________________________
___________________________
 Round lens: ____________________________
________________________

contracted
ciliary
muscle
relaxed
ciliary
muscle
fibers
slack
fibers
taut
rounded
lens
A Near vision
flattened
lens
B Distance vision
Cornea and lens bend light rays to converge on retina.
Two types of light detecting cells (photoreceptors):
Rod cells: ________________, detects dim light, responds to
change in light intensity. Provide course vision and detects
Cone cells: provide acute daytime vision, detects __________
Three types: one absorbs ____light, one absorbs _____
light and one absorbs _______light
Fovea: greatest density of cones
The region of the retina through which the optic nerve exits lacks
photoreceptors. It cannot respond to light and thus causes a
“______________________”
6 common visual disorders

Color blindness: one or more types of
cones are __________________________
› Red–green color blindness: X-linked
_______________ trait

Astigmatism: vision is blurred at all
distances by an ________________________
_______________________

Nearsightedness: ________objects are out of
focus
› Distance from the cornea to the retina is _______
than normal; ciliary muscles contract too much

Farsightedness: __________objects are out of
focus
› Distance from the cornea to the retina is
unusually _________; ciliary muscles are too weak

Cataract: scatters light and ___________vision
› Lens may become fully ________, causing blindness

Age-related macular degeneration (AMD):
destruction of ________________in the macula
clouds the center of the visual field
› Macula: part of the retina around and including
the fovea

Glaucoma: too much aqueous humor builds
up inside the eyeball
› Increased fluid pressure damages ____________and
ganglion cells
Properties of sound
Vertebrate ears
Hearing is the detection of sound: a form
of ______________________________
 Sounds arise when a vibrating object
causes __________________________

› Amplitude: _________of the waves;
determines how ____________a sound is
› Frequency: ____________of wave cycles per
second, or hertz (Hz); determines the
__________ of a sound
Low
note
Soft
Loud
High
note
A Same frequency,
different amplitude.
B Same amplitude,
different frequency.
Outer ear: the ______collects sound
waves and funnels them ____________
 Middle ear: consists of the __________and
______________________

› ___________________________________________
___________________________________________

Inner ear: consists of the vestibular
apparatus and the ________________
› Functions in _____________ and ____________

Cochlea: pea-sized, fluid-filled structure
that resembles a _______________________
› Consists of ________________________________

Sound waves vibrate three tiny bones of
the middle ear
› One of these bones (__________) pushes
against the _____________and creates a
______________ in the cochlea’s fluid
› Walls of the cochlea’s three ducts __________

Organ of Corti: sits on the base of the
membrane in the _____________________
› Contains mechanoreceptors (_____________)
involved in hearing
Sound-derived pressure waves cause the
membrane to move and the cilia of hair
cells to bend; __________________________
 Auditory nerve carries action potentials
from each cochlea to the _____________

Monitor body’s ___________and ___________
 Vestibular apparatus contain fluid filled
organs of Equilibrium

› ____________________________________
› ____________________________________
› They contain _________________________
› Changes in pressure triggers __________________