Chapter 13 (resp) Flashcards
t/f: inspiration always requires muscle contraction
TRUE
t/f: during expiration, intra-alveolar pressure increases
true
t/f: muscles of respiration are smooth muscle
false
purpose of respiration
gas exchange (o2 & co2) heat exchange water loss acid/base balance communication (breathing and talking)
respiratory system steps of external respiration
- ventilation or gas exchange between the atmosphere and air sacs (alveoli) in the lungs
- exchange of o2 and co2 between air in the alveoli and the blood in the pulmonary capillaries
Circulatory system steps of external respiration
- transport o2 and co2 by the blood between the lungs and the tissues
- exchange co2 and o2 between the blood in the systemic capillaries
- cellular respiration
t/f: increasing volume decreases the pressure
true
inspiration muscles
- diaphragm
- external intercostal muscles
- scalenus and sternomastoid muscles
expiration muscles
- abdominal muscles
- internal intercostals
t/f: inspiration can be passive or active
false
t/f: expiration can be passive or active
true
how does the diaphragm move when contracted?
downward
how do the external intercostal muscles move when contracted?
upward and inward to elevate the ribs
what happens if you damage the diaphragm?
respiratory paralysis
t/f: active expiration decreases lung volume
true
what is compliance?
how much effort is required to stretch
what happens to transmural pressure when compliance increases
increases
how do you see an increase in transmural pressure
intrapleural pressure being greater than the atmospheric pressure
increasing compliance does what (expand/contract) to the thoracic cavity and how?
expands thoracic cavity via stronger contraction of inspiratory muscles
increasing compliance does what to surfactant production
increases
decreasing compliance does what to surface tension
increases
surface tension is reduced by
surfactant
surfactant is produced by what cells
type 2 alveolar cells
how does increasing alveolar radius affect inward collapsing pressure?
decreases
what does surfactant do?
decrease hydrogen bonds to decrease water particle attraction
what is surfactant made of
lipids and proteins
decreasing radius without surfactant does what to inward collapsing pressure (collapse tendency)
increases
what is elastic recoil
how readily the lungs rebound after being stretched
how is elastic recoil affected by emphysema
increased
a decrease of elastic recoil causes:
difficulty breathing (with increased resistance)
t/f: elastic recoil is decreased by surfactant
true
t/f: compliance is a measure of the change in lung volume from a change in transmural pressure gradient
true
t/f: surfactant discourages against alveolar collapse
true
t/f: surfactant facilities lung expansion
true
what forces keep the alveoli open
transmural pressure gradient and pulmonary surfactant
what forces promote alveolar collapse
elasticity of stretched pulmonary connective tissue fibers (recoil) and alveolar surface tension
atmospheric pressure
760 mmHg
intraalveolar pressure is found where
inside the lungs
intrapleural pressure is found where
in thorax- not in lungs
what pressures keep the alveoli open
intra-alveolar pressure (out pushing) > intrapleural pressure (in pushing)
pressure changes during inhalation
- expand chest cavity
- decrease intrapleual pressure
- decrease intra-alveolar pressure below atmospheric
- draw air into alveoli
pressure changes during exhalation
- decrease intrathoracic volume
- increase intrapleural pressure
- increase intra-alveolar pressure above atmospheric pressure
- air leaves alveoli
pressure changes between breaths
intra-alveolar pressure = atmospheric pressure
when does intrapleural pressure exceed intra-alveolar pressure?
forcefully coughing
what is the main characteristic of pneumothorax
air in pleural cavity due to compromise or piercing from outside
why do the lungs collapse during pneumothorax?
intra-alveolar pressure is equal to atmospheric pressure
- increased volume
- decreased pressure
t/f: resting expiration is passive
true
t/f: exercise expiration is active
true
what muscles cause active expiration
accessory expiratory muscles
t/f: parasympathetic tone increases resistance which cause bronchoconstriction
true
t/f: sympathetic tone decreases resistance which causes bronchodilation
true
what receptor contributes to sympathetic tone causing bronchodilation
beta 2 agonist- has no affect on the heart and counteracts constriction
t/f: intrapleural pressure is always below intra-alveolar pressure
true
t/f: pressure increases in the thoracic cavity as volume decreases
true
what is tidal volume
air entering/leaving per breath
inspiratory reserve volume
extra volume that be inspired beyond regular tidal volume
inspiratory capacity
maximum in quiet inspiration (TV + IRV)
expiratory reserve volume
extra volume that can be expired beyond regular tidal volume
residual volume
minimum volume remaining after max. expiration
functional residual capacity
volume remaining after passive expiration (ERV + RV)
Vital Capacity
maximum volume moved out during one breath following max. inspiration
t/f: only 3% of total body energy is spent on breathing
true
Increasing respiratory volume effects:
- decrease compliance
- increase resistance
- decrease recoil
- increased demand
COPD affect on resistance and respiratory volume
increase; decrease
t/f: increasing respiratory volumes causes inadequate passive expiration
true
obstructive pulmonary disease
harder to breath out than in
- airflow limiting disorder
causes of obstructive pulmonary disease
- cystic fibrosis
- asthma
- bronchiectasis
- bronchitis
- emphysema
cystic fibrosis
mainly affects males; causes thick mucus production and lack of serous production in lungs; increases resistance by decreasing diameter
what is COPD
combination of asthma and emphysema
what is bronchiectasis
airway collapse
bronchitis
inflammation of bronchioles
what does bronchitis do to the radius and how does that affect resistance?
decreases radius, increases resistance
emphysema
air trapped outside alveoli that has nowhere to go
if lungs are hyper-inflated, what happens?
can’t get the air out that you need to, decrease expiratory reserve volume, bronchioles collapse
restrictive pulmonary disease
harder to get air in than out- diaphragm may contract but super hard to completely open
t/f: restrictive pulmonary disease is also known as low air-volume disorder
true
intrapulmonary restrictive pulmonary disorder
- pneumonia
- pulmonary fibrosis
- pulmonary edema
extrapulmonary restrictive pulmonary disease
rib fractures and neuromuscular
pulmonary ventilation
tidal volume x respiratory rate
deadspace
volume of air not used for gas exchange
volume of deadspace
150 mL
alveolar ventilation
(tidal volume - dead space) x respiratory rate
how does decreased o2 affect pulmonary arterioles
vasoconstrict
how does decreased o2 affect systemic arterioles
vasodilation
how does increased o2 affect pulmonary arterioles
vasodilation
how does increased o2 affect systemic arterioles
vasoconstriction
partial pressure gradients
determines how much of a substance will be dissolved in the blood
partial pressure gradient percentages of n2, o2, and co2
Pn2= 79% Po2= 21% Pco2= 0.04%
t/f: partial pressure of o2 determines how much hemoglobin is bound
true
alveolar air partial pressures
Ph2o= 47 mmHg Pn2= 563 mmHg Po2= 100 mmHg (lowered from 150) Pco2= 40 mmHg
what contributes to the decrease in partial pressure of o2 in alveoli? and how?
water and dead space
- water remains when air is depleted, then when air enters, the pressure is decreased
what does nicotine do to thickness and exchange?
increases thickness, decreases exchange
t/f: gas always diffuses down partial pressure gradients (high to low)
true
t/f: arterial pressure is higher than alveolar pressure
false
why does Pco2 increase after exchange?
co2 released from tissues to be released through expiration but also maintains pH and the acid-base balance
rate of exchange
surface area where exchange occurs
t/f: increasing pressure difference increases exchange
true
influences on exchange
- surface area (A)
- membrane thickness (Δx)
- solubility (B)
how does solubility influence exchange
co2 is more soluble than o2
what diseases affect exchange
increased membrane thickness (decrease)
reduction in surface area (decrease)– emphysema
fick’s law of diffusion
Q= (ΔC * A * B)/ (MW^1/2 * ΔX)
lipid soluble substances
- oxygen
- carbon dioxide
- anesthetics
- ethanol
local control to adjust ventilation to a lung area with large airflow and small blood flow
decreases co2 in area → increased contraction of local-airway smooth muscle → constrict airways locally → increase airway resistance → decrease airflow
local control to adjust perfusion to a lung area with large airflow and small blood flow
increase o2 in area → relaxation of local pulmonary arteriolar smooth muscle → dilation of blood vessels locally → decrease vascular resistance → increase blood flow
when do arterioles at the top of the lungs dilate?
when they sense a lot of o2
when do arterioles at the bottom of lungs constrict?
when o2 is low
why do you toss and turn at night?
maintain ventilation-perfusion ratio
local control to adjust ventilation to a lung area with large blood flow and small airflow
increases co2 in area → relaxation of local-airway smooth muscle → dilate airways locally → decrease airway resistance → increase airflow
local control to adjust perfusion to a lung area with large blood flow and small airflow
decrease o2 in area → increased contraction of local pulmonary arteriolar smooth muscle → constriction of blood vessels locally → increase vascular resistance → decrease blood flow
t/f: oxygen is greatly soluble in plasma
false
what attaches to hemoglobin
oxygen
how much hemoglobin is attached to oxygen
98.5%
reduced hemoglobin (deoxyhemoglobin)
not combined with oxygen
oxyhemoglobin
oxygen combined with the heme group
t/f: when oxygen is bound to hemoglobin it has a great effect on Po2
false
what does hemoglobin do?
remove o2 from the blood so more can be dissolved
in the lungs, how much hemoglobin is saturated?
97.5%
after exchange, how much hemoglobin is saturated?
90%
t/f: hemoglobin prolongs existence of pressure gradient
true
t/f: as partial pressure of oxygen decreases, hemoglobin releases more o2
true
when do we see more oxygen delivered?
hemoglobin saturation with slight changes in amount of oxygen in the blood
- large change in hemoglobin saturation, small change in partial pressure of o2
how much o2 in the blood is removed by the heart?
65%
what is the primary driver for respiration
carbon dioxide
t/f: increasing partial pressure of o2 in pulmonary capillaries will shift the curve right
true
t/f: decreasing partial pressure of o2 in systemic capillaries will shift the curve left
true
steep portion of hemoglobin curve allows:
a large amount of o2 available to the tissues
how low does o2 have to get in blood to trigger respiration
65 mmHg (can fall below at high altitidues)
increase co2 does what to hemoglobin
causes hemoglobin to release more o2 (right shift)
increase hydrogen ion concentration does what to pH
decreases pH (shift right)
increase in BPG does what to hemoglobin?
hemoglobin release more o2 (shift right)
carbon monoxide does what to hemoglobin?
causes hemoglobin to hold onto more o2 causing a decrease in amount of o2 going to the tissues (shift left)
how does increasing temperature affect hemoglobin?
cause hemoglobin to release more o2 to tissue at higher temperatures (shift right)
t/f: carboxyhemoglobin is the dominant hemoglobin
true
decrease pH= ____ acidity = _____ H+ ions
increase; increase
t/f: a left shift of the hemoglobin curve releases more o2 to tissues
false
when is a right shift dangerous?
causes a decrease in exchange eventually which causes less oxygen to the tissues, hemoglobin is not picking up oxygen like it should be
t/f: 60% of co2 is transported as bicarbonate
true
bicarbonate buffer equation
co2 + h2o ⇿ h2co3 ⇿ h+ + hco3-
what does carbonic anhydrase do?
accelerate reaction which allows large amount of co2 to interact with red blood cells before leaving capillary bed
t/f: 30% of co2 is transported as carbaminohemoglobin
true
how much co2 is dissolved in the plasma
10%
what does co2 bind to in hemoglobin?
globin
what does o2 bind to in hemoglobin?
heme
hypoxia
insufficient o2 at the cellular level
haldane effect
reduced hemoglobin has a greater affinity to bind to co2
bohr effect
hydrogen is affecting hemoglobin’s ability to bind to o2
t/f: increasing hydrogen and carbon dioxide can actually help hemoglobin unload oxygen
true
t/f: hemoglobin has to release oxygen before carbon dioxide can bind
false
co2 binding to oxyhemoglobin aids in:
release of o2 from hemoglobin and increases o2 delivery to tissues
hyperventilation
release too much co2 (decrease co2)
increase pH
increase o2
hypoventilation
not enough movement of air
- decreased o2
- increased co2
pre-botzinger complex
pacemaker of breathing
- fires every 3-5 seconds
- pH sensitive
dorsal respiratory group (DRG)
stimulation= inspiration
lack of stimulation = expiration
t/f: DRG generates rhythm
false
ventral respiratory group (VRG)
inspiratory and expiratory neurons
active inspiration and expiration
pons respiratory center
fine tuning
- affect respiratory pattern
pneumotaxic center
inhibitory toward DRG
- prevent over inflation of lungs
apneustic center
protect DRG
pre-botzinger and dorsal respiratory complex create
tidal volume
t/f: when DRG is not activated: passive expiration occurs
true
t/f: VRG modifies breathing patterns and is responsible for active expiration
true
what happens if medullary respiratory center is damaged?
respiratory failure
if there is pressure on the DRG area, what kind of breathing would occur?
active breathing only
- no passive breathing bc DRG would be constantly activated by the pressure
t/f: if apneustic center is in control, severe brain damage will occur
true
t/f: arterial Po2 is a strong driver of regulation
false
what is arterial Pco2 indicative of?
hydrogen levels
increasing arterial Pco2 will weakly do what?
activate peripheral chemoreceptors which will feed into the medullary respiratory center which will increase ventilation and decrease arterial Pco2 to relieve the initial increase
what does an increase arterial Pco2 pathologically do?
affect medullary respiratory center which will increase ventilation and decrease Pco2
how does an increase of arterial Pco2 affect the brain?
increase brain-ECF Pco2 which then increase Brain-ECF H+ due to carbonic anhydrase (bicarbonate buffer system) which will activate the central chemoreceptors which feed into the medullary respiratory center which will increase ventilation and decrease arterial Pco2 to relieve the initial increase
