ch 2 quiz Flashcards
what 4 cranial nerves are involved in breathing?
glossopharyngeal IX
hypoglossal XII
vagus X
accessory XI
what do each of the cranial nerves involved in breathing do?
- glossopharyngeal IX, hypoglossal XII, and vagus X all dilate the larynx and stiffen the upper airway
- accessory XI elevates the rib cage
what spinal nerves run through the rib cage wall?
C1-L2
what spinal nerves run through the diaphragm?
C3-C5
what spinal nerves run through the abdominal wall?
T7-L1
explain afferent vs efferent
SAME
DAVE
afferent is sensory neurons going to the cns
efferent is motor neurons coming from the cns
tidal breathing
- automatic breathing
- controlled be brainstem (medulla)-special groups of neurons generate rhythmic breathing patterns and regulate gas levels
- influenced stongly by afferent info, but can be influenced by other senses like visual, emotions, awareness, etc
where does afferent information used by the medulla to control breathing come from?
mechnoreceptors and chemoreceptors
chemoreceptors
sensitive to chemical status
central vs peripheral chemoreceptors
central: located on front and side of medulla, respond to carbon dioxide level in cerebrospinal fluid
peripheral: located in common carotid arteries, responds to oxygen levels
mechanoreceptors
- mechanical change (stretching, pulling, etc)
- located in chest wall (sense changes in muscle length)
- and pulmonary apparatus (respond to stretching of smooth muscles, airway irritants, and distortions in the alveolar wall
special acts of breathing
- anything that’s not tidal breathing
- controlled by higher brain centers that can override the brainstem
- ie, brain overrides brainstem for non-tidal (special) acts of breathing (eg. blowing, talking, holding breath)
purposes of resting tidal breathing
ventilation (moving of air into and out of the breathing apparatus) and gas exchange
gas exchange
- occurs at the level of the alveoli
- alveoli makes contact with the bloodstream to deliver oxygen and take up carbon dioxide
resting tidal breathing
lots of random stuff
- follows regular in/out pattern
- expiration & inspiration about = duration
- driven by pressure gradient creating by changing alveolar pressure
- breathing patterns change based on different people and body positions
- diaphragm is primary driver of inspiration
- passive force (recoil) is primary drive of expiration
- rib cage wall muscles activate slightly to stiffen
- abdominal muscles are active and upright
- when supine, ab muscles aren’t active becauase gravity is already bringing abdominal wall in
breathing and speech production overview
2 forms
extended steady utterance: long note, extended monologue
running speech: converstation (taking turns, etc)
extended steady utterance
- uses deepest inspiration and continues until movable air supply is depleted (most of vital capacity)
- sustained vowel, sung note, etc
- lung volume, alveolar pressure, rib cage and abdominal wall volume are affected differently
can’t produce speech without pressure in the lungs allwoing it to occur
checking action expiratory muscles
as an utterance uses up most of our vital capacity, the expiratory muscles will engage to maintain enough pressure for speech production
checking action inspiratory muscles
- speech requires a slower release of air than tidal breathing
- to generate pressure needed for sustained utterances, the inspiratory muscles must hold back the high expiratory relaxation pressure needed to expire
- ie inspiratory muscles check the speed of expiration
misc fact about extended steady utterance
constantly changing muscle activities are required to maintain target alveolar pressure
running speech
- uses about twice the resting tidal volume and continues until near resting tidal volume (midrange of vital capacity), but varies by speech activity
- normal speech
- inspirations are fast, expirations are slow
memorize the first point!
running speech pressure
- similar to breathing for ESU both relaxation pressure and muscular pressure contribute to running speech breathing
- pressure for rs is usually higher than tidal relaxation pressure
- muscular pressure is needed to increase alveolar pressure to target range
- only expiratory muscles (rib&abdominal) are used
- louder speech needs higher alveolar pressure (starts with larger lung volumes to create larger relaxation pressure) & increased muscular pressure
- soft speech is the opposite
boyle’s law
pressure and volume are inversely related, only applies if we are holding our breath because the breathing system is an open system
running speech shape
- the shape of the chest and abdominal walls can tune the breathing apparatus for quick inspiration and pulses of expiration (needed for normal speech)
- fills the need for checking action
- abdominal wall displaced inwardly (less than relaxed)
- diaphragm is pushed up
- chest wall displaced out (more than relaxed), because diaphraphm is pushing up
the diaphragm
(all pertinent information)
- primary driver of inspiration
- responsible for changing the volume of the thorax (key to respiration)
contraction of diaphragm - down and forward=vertical thoracic expansion
- elevation of lower ribs=vertical thoracic expansion
passive and active forces of breathing
- active: muscle contraction
- passive: natural recoil–surface tension of alveoli–pull of gravity–rib torque
new sneakers perfect running
vertical exscursion of rib front end
- upward & forward or down and back movement
- results in increase or decrease of front to back rib cage diameter
vertical excursion of side of rib cage
- upward & outward or downward and inward movement
- results in increase or decrease of side to side diameter
tidal volume
The volume of air inspired or expired during the breathing cycle.
inspiratory reserve volume
The maximum volume of air that can be inspired from the tidal end-inspiratory level
expiratory reserve volume
The maximum volume of air that can be expired from the tidal end-expiratory level
residual volume
The volume of air remaining at the end of a maximum expiration
vital capacity
The maximum volume of air that can be expired after a maximum inspiration (or inspired after a maximum expiration)
functional residual capacity
The amount of air in the pulmonary apparatus at the resting tidal end-expiratory level
total lung capacity
the volume of air in the pulmonary apparatus after a maximum inspiration
inspiratory capacity
the maximum volume of air that can be inspired from the resting end-expiratory level
describe the relaxation pressure curve
-at maximum inspiratory pressure you have exhaled all the air that you can, so you have a low vital capacity and also a low, negative alveolar pressure
-at maximum expiratory pressure you have inhaled all the that you can, so you have a high vital capacity and high alveolar pressure
-the relaxation curve is just your normal breathing and it doesn’t have extreme pressures on either side
