ch5.3

Question 1

what do smell and taste involve together

Answer 1

Together are called the chemical senses because they
involve responses to particular chemicals

Question 2

how did olfactory and gustatory senses evolve

Answer 2

both emerged early in evolutionary history
* The smell is of lesser importance to humans than other
species
* Both are important (e.g., smelling or tasting rotten food,
noxious gases, smoke)

Question 3

odorants

Answer 3

airborne chemicals that are
detected as odours

Question 4

olfactory receptor neurons

Answer 4

the receptor
cells bind odorant molecules into a neural
impulse (transduction) and send that
impulse to the brain

Question 5

taste

Answer 5

What we call ‘taste’ is actually flavour, a combination of taste
and smellp

Question 6

bumps that cover the surface of the tongue

Answer 6

papillae

Question 7

clusters of sensory receptor cells (in the
papillae) that bind the food molecules that dissolve in our
saliva and turn this information into a neural impulse
(transduction)
* Each one contains 60-100 sensory receptor cells for taste

Answer 7

taste bud

Question 8

5 taste receptors

Answer 8

We have 5 taste receptors
1. Sweet
2. Sour
3. Bitter
4. Salt
5. Umami – taste of glutamate
(MSG)

Question 9

what is one thing eating includes that we dont expect

Answer 9

Eating also includes touch or tactile sense and plays a large role in our food preferences (e.g., oysters, ricotta
cheese, green beans)
* Spicy food can activate our pain receptors through the
release of a chemical called capsaicin
* Couple the pain with food texture and flavour can produce a pleasurable sensation, it can even become ‘addictive’

Question 10

Signals from olfactory nerves travel to the

Answer 10

olfactory bulb

Question 11

where is olfactory information sent in the brain

Answer 11

The olfactory information is sent to other
regions of the cerebral cortex to recognize
and discriminate odours

Question 12

The olfactory bulb sends information to the

Answer 12

amygdala
and indirectly to the hippocampus
* Smell can evoke memories

Question 13

Taste receptors send information to the

Answer 13

thalamus and,
eventually, the gustatory cortex in the frontal lobe

Question 14

• Taste and smell converge in the

Answer 14

neocortex (prefrontal)

Question 15

The Development of Smell and Taste

Answer 15

• Smell is well developed at birth and within hours can
  detect moms compared to other women
• Taste is also well developed at birth, with an innate
  preference for sweet and an aversion to bitter or sour
  tastes
• By 7 yrs, children begin to develop a preference for
  sour, but remain averse to bitter until young adulthood
• Taste and smell receptors are constantly changing

Question 16

inability to taste

Answer 16

ageusia

Question 17

phantom averse to taste most common

Answer 17

dysgeusia

Question 18

inability to smell, can still taste but not
‘flavours’

Answer 18

anosmia

Question 19

The tactile or somatosensory system

Answer 19

is a
combination of skin senses:
*Pressure, touch, temperature, vibration, and
painta

Question 20

tactile senses rely on

Answer 20

a variety of
receptors located in different parts of the skin

Question 21

light pressure

Answer 21

merkells disk

Question 22

lower pressure and lower frequency vibration

Answer 22

messners corpuscle

Question 23

transient pressure and higher frequency vibrations

Answer 23

pacinian corpuscle

Question 24

detects stretch

Answer 24

ruffini corpuscles

Question 25

how does pain differ from other sensation

Answer 25

No one stimulus triggers pain

Question 26

Pain is triggered by a group of sensory
receptors called

Answer 26

nociceptors

Question 27

nociceptors

Answer 27

Pain is triggered by a group of sensory
receptors called nociceptors
*Free nerve endings in the skin, muscles, joints,
organs
*Detecting temperature, pressure and chemicals
(eg., Capsaicin)

Question 28

what type of cognition is pain

Answer 28

*Pain is both bottom-up and top-down cognition
*Pain is a biopsychosocial event

Question 29

what influecnes pain

Answer 29

Genes influence the experience of
pain and other physical
characteristics.
* Women have a lower threshold for
pain and experience greater
intensity
* Men may be less willing to admit
when they feel pain

Question 30

gate control theory

Answer 30

• The spinal cord contains a neurological gate that controls the
  transmission of pain to the brain.
• Small spinal cord nerve fibres conduct most pain
• An injury activates these fibres and opens the gate, the signal is then
  relayed to the brain
• Large fibre activities (eg., Massage) closes the gate
• Chronic pain can be treated by gate-closing stimulation such as
  massage, acupuncture etc.
• Endorphins are also released in response to severe pains
• The brain can also create pain (eg., Phantom limb sensation)

Question 31

tactile senses and the brain

Answer 31

Neural impulses travel from the tactile
receptors and nerve endings to the
medulla, thalamus and the
somatosensory cortex

Question 32

psychosocial influences on pian

Answer 32

Perception of pain is influenced by attention.
*Pain is a product of our expectations. and culture
as well.
*We tend to perceive more pain when others also
seem to be experiencing pain
*When people feel empathy for another person’s
pain, their own brain activity partly mirrors the
activity of actual brain pain

Question 33

development of tactile sense

Answer 33

• Generally well-developed at birth
• Infants respond to touch at birth
• Harlow’s rhesus monkey experiment showed that touch
  is necessary for normal development
• Other senses influence tactile sensations like not
  seeing something (e.g., expectation)

Question 34

kinesthetic

Answer 34

receptor cells (proprioceptors) in your
muscles, joints, and tendons tell the brain when we
are moving and where our body parts are in space

Question 35

vestibular

Answer 35

located in the semicircular canals and
vestibular sacs of our inner ears. The movement of
fluid in these canals tells us if we are standing up
or swaying from side to side.
* Helps us to maintain balance