Speech mech chapter 8 part 2 Flashcards
Eating involves the following
criteria
Important for eating to be pleasant
*hint: Hunger will drive people to acquire
nutrition
Food should be
palatable to be eaten in
sufficient amounts for good nutrition
Stages of swallowing must be
supported by an adequate
neuroanatomical substrate
gustation is also called
Critical component of chewing,
sucking, and swallowing (CSS)
Taste receptors (buds or cells) found
in
papillae of tongue epithelium are
chemoreceptors for gustation
*hint : Transmit information to the brain about
taste
Tastes can be sensed all over tongue. What Types of taste do you have ?
Salty, sweet, sour, bitter, and umami
* Umami is meaty taste of monosodium glutamate
Taste sense determines
whether a
bolus is ingested or ejected from
mouth
taste is Mediated by the
VII facial, IX
glossopharyngeal, X vagus and V
trigeminal nerves
Oral chemethesis
- Detecting chemical stimuli by oral
thermal and pain receptors
– Can sense bacterial invasion and
trigger sneeze
Oral Chemethesis Therapeutic use of carbonation or
citrus reduced
swallowing latency in
individuals with dysphagia although
the bolus was so strong to be
unpalatable
Olfaction is the
sense of smell
Olfaction plays vital role in
appetite and
taste
Olfactory sensors have
a short life
and are continually replaced
Olfaction arrives
at cerebral
cortex through multiple pathways
involving olfactory discrimination
Pleasant food odors
produce
salivation
Unpleasant food odors
produce
gagging or even vomiting
Sense of touch mediated by many
mechanoreceptors (sensors)
Sensors that are sensitive to physical contact. This is….
Broadly distributed about the body
*Differentiated by type of stimulus causing
response
Glabrous (hairless) skin contains
Meissner’s corpules and Merkel disk receptors-
transmit movement and pressure
Deep cutaneous skin contains:
Pacinian corpules and Ruffinni ending- respond to
deep pressure and stretch
Vibration sense
Subclass of tactile sense
; Sensed by deformation of tactile
receptors
Two point discrimination
Measuring sense of touch by
perceiving two probes as two versus
one stimulus
Four classes of thermal receptors
Warm, hot, cool, and cold
what do Pain sensors (Nociception)
- Produce perception of pain when
traumatized
– Important in development of structural
disorders of swallowing
– May respond to traumatic or thermal
trauma
Muscle stretch is sensed by
muscle spindle fibers
– Found within the oral musculature
* Mandibular elevators richly endowed with
sensors
Muscle tension is sensed by
Golgi tendon organs (GTOs)
*hint : found within the tendons and fascia and Respond to active contraction of muscles
salivation Result of
release of saliva into the
oral cavity, motor response
salivation is a component of
mastication and
deglutition
Product of three major glands
– Parotid gland secretes serous saliva
– Submandibular gland produces thin
serous secretions and mucus
– Sublingual gland produces thick
mucus
Reflexive Circuits of Mastication
and Deglutition
individual reflex circuits
Processes dealing with eating and
drinking
Chewing, rooting, and sucking reflexes
* Uvular, gag, retch, and vomit reflexes
* Cough reflex
* Tongue base retraction and elevation
* Pain and respiration reflexes
chewing reflex is triggered by
deep pressure on
roof of mouth
chewing reflex is involves
rotary motion of
mandible
*hint: Bolus is moved into and off of the molars
Chewing center located within
midbrain
Center involved in reflexive movements
of tongue for sucking and licking
rooting and sucking reflexes are
Important for neonates and
infants
Rooting reflex
Tactile stimulation of cheek causes
infant’s mouth to open
Sucking reflex
Created by soft contact with inner
margin of lips
* Causes a sucking response
Uvular (Palatal) Reflex
Mediated in manner similar to gag reflex
Gag (pharyngeal) reflex
Helps individuals avoid aversive stimuli
– Tactile stimulation of faucial pillars,
posterior pharyngeal wall or posterior
tongue
Gag (pharyngeal) reflex can be
elicited by taste
* Causes respiration to cease
* Causes pharynx to elevate and constrict
Retching
Involuntary attempt at vomiting
– Caused by noxious smells, tastes,
gastrointestinal distress, vestibular
dysfunction, upsetting visual
stimulation
Vomiting (emesis)
Oral expulsion of gastrointestinal
contents
cough reflex is Initiated by
noxious stimuli of
the pharynx, larynx, or
bronchial passageway
Cough Reflex Involves
laryngeal adduction
and abdominal contraction
– Increases subglottal pressure
– Produces forceful exhalation
Pain withdrawal reflex
Affects mastication and swallowing
* Causes a natural withdrawal from noxious
stimulus
Oral and pharyngeal pain responses
Individual acts to remove excessively hot or
spicy food by swallowing or expectoration
Apneic reflex-
Stimulation of oral cavity, pharynx or
larynx
*hint: Cease respiration
Respiratory reflex
– Under partial voluntary control
– Respiratory centers located in lower
medulla
– When oxygen levels decline below
criteria, respiration rate increases
Causes of respiration
– Inadequate oxygenation in the blood
– Increased carbon dioxide in the blood
– Increased acidity
Mastication and deglutition are
governed by
unconscious,
automatic sensorimotor system but
can be consciously controlled
what is Centrally generated processing
(CPG)
– Two networks in medulla oblangata:
* Dorsal swallowing group- generate swallow
pattern
* Ventral swallowing group- activate motor
response
