respiratory function Flashcards
air exchange vs. ventilation
oxygen in CO2 out
accomplished by chemical diffusion
respiration is
mechanical
ventilation process that brings ____ air and removes ____ air
oxygenated, deoxygenated
speech rides on
the ventilation mechanism
as ability to ventilate is compromised so is speech
breathing proceeds automatically
controlled by medulla
active when sleeping, reading quietly, most of infancy
changes is pattern are volitional or innate
-must temporarily override basic life support pattern
learn a pattern that supports an activity *like speech
switch to a different automatic pattern for crying, laughing or swallowing
respiratory cycle
one inhalation and one exhalation (inspiration and expiration)
includes air exchange within lungs
quiet tidal respiration
12-18 cycles per minute
500 ml per cycle
active respiration
activity/stress induced changes
other modes of respiration
speech respiration
singing respiration
pathological patterns
contrast tidal vs. speech
quiet tidal breathing is the automatic respiration when at rest
symmetry of inhalation and exhalation
active muscle force during inhalation not exhalation
active force during respiration
muscle actions
muscle activity only required for inhalation during passive respiration
complex combos of muscle activity modify inhalations during speech, song, and for higher respiratory demands
passive force during respiration
elastic restoring forces drive passive exhalation always present
elasticity
the tendency of a body to return to its original shape after it has been stretched or compressed
gravity
assists exhalation in upright position
inhalation
contraction of inspiratory muscle expands lungs
creates negatice pressure within lungs relative to atmospheric pressure
pattern of air in inhalation
- air is drawn into lungs
- eventually reaches terminal bronchioles
- oxygen rich air reaches alveoli
- alveoli are the air exchange cells (300 million)
respiration mechanism
rich distribution of alveoli makes lungs spongy
-each alveolus supplied with capillaries from pulmonary artery
most inhalation through nose
-inhalation warms and moistends air which promotes air exchange
-contaminants within air are trapped by cilia within nose and mucus or picked up by lymphatic system
single passive respiration cycles:
diaphragm and ext intercostals contract
diaphragm fibers contract pulling down central tendon
increases vertical dimension of thorax
compresses abdominal contents
single passive respiration cycle:
external intercostals elevate ribs enlarging anteroposterior and lateral dimension of thorax
intercostals and intercartilaginous inter intercostals evert (rotate) ribcage
negative pleural pressure binds lungs to throacic cavity
single passive respiration cycle:
expansion of thorax expands lungs
generates a slight negative alveolar pressure within lungs relative to atmospheric pressure
air flows in until alveolar pressure equals atmospheric
muscles of inhalation cease activity
single passive respiration cycle:
passive forces of exhalation take over “elastic rebound”
abdomen rebounds pushing diaphragm upwards
rib cage untwists (rotates) bacj to original position through elastic rebound
single passive respiration cycle:
alveolar pressure rises slightly relative to atmospheric pressure
air is pushed out of the lungs
default mode of breathing
tidal breathing
an easy, slow, symmetrical pattern of air flow on inhalation and exhalation
-driven by a “circuit” in brainstem that seeks to achieve automatically
how does respiration change during speech
basic life support automatically over-ridden
respiration must now support the volational goal of info exchange
speech pattern breathing
becomes highly regular and sinks below awareness
speech is ____ inspiration and a _________ expiration
- active, passive & active
- exhalation slowed by “checking action” of inhalation muscles
typical speech still does not stress respiratory system
- typical speech requires higher volume of air exchange than quiet respiration
- should never stress the healthy system
speech vs tidal breathing
speech involves increased proportion of “vital capacity” relative to quiet respiration
- air we use during functional activities
- loud speech increases proportion of vital capacity
pressure demands for speech
- pressure required during exhalation
- air pressure generated with trachea below larynx - tracheal pressure
minimum pressure to initiate phonation
2-3 cm H20
conversational speech
7-10 cm H20
loud speech, shouting and singing
15-20+ cm H20
how do we control these pressures
elastic rebound of lungs and ribcage should set limits for passive forces
different volumes of air are exchanged depending on the activity
- certain volumes of air represent a reserve
- air that can be drawn in or expelled
- includes typical air exchange and volumes beyond this range
- volumes and capacities can represent function and limits of respiration across entire range of air exchange
volumes
discrete amount of air held in certain cavaties
- do not overlap
- volumes differ from person to person and change over time
capacities
combinations of volumes that express functional range of system
-capacities include more than one volume and are more variable
tidal volume
amount of air exchanged during a single respiration cycle
young adult males tidal volume
675-895 ml
young adult females tidal volume
285-393 ml
young adult males during light-heavy exertion
1670 ml - 2030 ml
inspiratory reserve volume
amount of air that can be inhaled beyond inspiratory reserve
1500-2500 ml
expiratory reserve volume
amount of air that can be forcibly exhaled following a passive or quiet exhalation
(resting lung volume)
residual volume
the amount of air remaining in the lungs and airways even after a maximum exhalation
- a certain amount of air must fill trachea at any given time
- cannot be expelled, cannot be used functionally, but provides necessary air in the lungs for gas exchange
total lung capacity
sum of all the volumes
-total amount of air that can be held in the lungs
inspiratory capacity
maximum volume of air that can be inhaled from the resting expiratory level
tidal volume + inspiratory reserve volume
functional residual capacity
quantity of air in lungs at the resting expiratory level
expiratory reserve volume + residual volume
vital capacity
quantity of air that can be exhaled after as deep an inhalation as possible
tidal volume + inspiratory reserve volume + expiratory reserve volume
-functional range of respiration
-encompasses all demands on respiration
-far exceeds speech respiration demands in normal hearing
all respiration activities occur within
vital capacity
young adult male vital capacity
4.6 liters
young adult female vital capacity
3.1 liters
athlete vital capacity
can expand range by 30-40%
capacities and volumes _____ when lying down relative to standing
decrease
- gravity no longer supports respiration
- inhalation must work against gravity using muscle action
- RLV decreases from standing to supine
- elastic forces do not expand thorax to same degree
- more effort required for inspiration
levatores costarum
origin: tip of transverse process
insertion: attaches to superior border and external surface of rib
innervation: cranial and thoracic nerves
function: elevates ribs
breathing apparatus
active forces: inhalation & exhalation
passive forces: inhalation & exhalation
pulmonary apparatus
passive forces: exhalation
chest wall
active forces: inhalation & exhalation
passive forces: inhalation & exhalation
rib cage wall
active forces: inhalation & exhalation
passive forces: inhalation & exhalation
diaphragm
active forces: inhalation
passive forces: inhalation
abdominal wall
active forces: exhalation
passive forces: inhalation & exhalation
pulmonary apparatus
passive
trachea
pulmonary airways
lungs
chest wall
active rib cage wall abdominal wall diaphragm chest wall
pulmonary-chest wall unit
active & passive
-speech can extend beyond resting lung volume (RLV) by
contracting muscles of expiration
