respiratory system chp 10 Flashcards
What is ventilation?
mechanical process moving air into & out of lung
What is respiration? “pulmonary”
exchange of gas in lungs
pulmonary inspiration is (internal/external)?
External
- it brings O2 from outside the body into the lungs
- exchanges 02 for CO2 at the lungs
Cellular Respiration
- which was does O2 move?
O2 moves into the cells (down its gradient)
Cellular Respiration
- which way does CO2 move?
CO2 moves out of the cells, into the blood
What is O2 being used for in Cellular Respiration?
Cellular metabolism
- final acceptor for electron transport chain!
What are the lungs enclosed in?
pleura
What pleura lines the outter surface of the lungs?
visceral
Which pleura is lining the thoracic cavity?
parietal
Is the space inbetween the parietal and visceral pleura + or -
ALWAYS (-)
** if it was + the lung would collapse
What is included in the conducting zone?
- trachea
- bronchi
- bronchioles
- terminal bronchioles
What is the job of the conducting zone?
to move & filter air (warms it up for the lungs)
What are the components of the respiratory zone
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
What is the job of the respiratory zone?
Gas exchange bw air & blood
What are alveoli?
tiny sacs where gas exchange occurs in lungs
How many cell layers thick are alveoli?
1!- helps increase diffusion rate!
What do they produce to make sure they dont collapse?
SURFACTANT!
What makes up the respiratory membrane?
- alveolar cell
- capillary membrane
2 layers thick!
What muscles do you use for inspiration??
- diaphragm!!! - most important
Do the lungs expand or contract upon inspiration?
expand
Which was does the diaphragm move during inspiration?
down + forward
During inspiration what happens to intrapleural pressure?
decreases (gets more - )
What muscles work during passive expiration?
NONE- its passive bc the lungs are elastic and recoil
what muscles work during exercising expiration?
rectus abdominus & internal oblique
What happens to the intrapulmonary pressure during expiration?
it increases!
where is the greatest resistance to airflow?
medium-sized bronchi
what factor alters resistance to airflow
diameter of the airway!
tidal volume
gas moved per breath
anatomical dead space
air that stays in the lungs and doesnt move
“unused ventilation”
alveolar ventilation
volume of inspired gas that reaches the respiratory zone
vital capacity
max amount of gas expired after max inspiration
residual volume
volume of gas remaining in lungs after max epiration
total lung capacity (TLC)
gas in the lungs after max inspiration
vital capacity + residual volume
What are you increasing the get the most alveolar ventilation? (tidal volume or frequency?)
TIDAL VOLUME
- BIG WAVES
Fick’s law
rate of gas transfer (V) is proportional to the tissue area (A) & difference in partial pressure (P1-P2) & diffusion coefficient (D)
V= A/T x D x (P1-P2)
If you increase the tissue surface area what happens to the diffusion of gas?
increases
increasing the diffusion coefficient does what to the rate of diffusion?
increases it
if you increase the tissue thickness what does it do to the diffusion?
decreases it
Daltons Law
total pressure of a gas mixture = the sum of each individual pressure
what is atmospheric pressure at sea level?
760 mm Hg
partial pressure of O2 at sea level
21%
partial pressure of N2
79%
partial pressure of CO2
.03%
Co2 is how many more times soluble than O2?
20
which gas is essentially insoluble in blood ?
N2
what is the major factor that determines the amount of dissolved gas?
partial pressure
where does o2 diffuse from
alveolus
what does co2 diffuse into?
alveolus
pressure in the pulmonary system are relatively low when compare to what?
systemic
what causes low pressures in the pulmonary system?
low vascular resistance
ideal ventilation to perfusion ratio
1
o2 is carried to the blood via what?
hemoglobin
what happens to bond strength btw hemoglobin & o2 with temp increase
weakens
what happens to strength of the bond btw hemoglobin and o2 when ph decreases
bond weakens
combination of hemoglobin and o2 in the lungs
loading
release of o2 from hemoglobin @ the tissues
unloading
what happens when more o2 is unloaded to working muscles?
vasodilation (increase blood flow)
extract o2 @ a greater %
what factors affect o2 carrying capacity & extraction during exercise?
temp
ph
how do we carry co2?
bicarbonate
what is the significance of the cl- shift?
replaces bicarbonate to create balance
function of carbonic anhydrase?
enzyme that catalyzes bicarbonate reaction
what is the best stimulus to increase ventilation
Co2
Functions of the respiratory system
- provide gas exchange bw environment & body
2. regulate acid-base during exercise
What happens if co2 concentration increases in alveoli ?
Decrease in perfusion
Increase in ventilation
What happens when there’s a decrease in O2?
Decrease in ventilation
Increase in perfusion
The apex of the lung is (over/under) ventilated oand (over/under) perfused?
Over ventilated
Under perfused
The base of the lung is (over/under) ventilated and (over/under) perfused?
Under
Over
Which increases most rapidly in the transition from rest to steady-state exercise?
Metabolism
Ventilation is less rapidly increased !!!!
What is the effect of metabolism increasing more rapidly than ventilation in exercise?
Initial decrease in PO2
What causes an increase in ventilation in hot/humid enviro
Increase in breathing frequency and dead space
What is hypoxemia?
Low PO2
Who is exercise induced hypoxemia more prominent in? (Male or females)
Females
Blood spends a reduced amount of time in the pulmonary capillary causing a lower PO2
Exercise induced hypoxemia
What can exercise induced hypoxia cause
Ventilation perfusion mismatch (what I just described on the last slide)
What controls the contraction and relaxation of the respiratory muscles?
Somatic motor neurons (which are controlled via the medulla oblongata)
What is the “group pacemaker hypothesis”
Firing of several clusters of neurons in the brain stem that generate breathing
The pacemaker theory suggest that regulation of breathing is under what type of control?
Redundant control
What is neural input to the respiratory system?
Input from neurons excited by means other than blood-borne stimuli
Can neural input be afferent or efferent?
BOTH!
Humoral input to the respiratory system come from 2 receptors via blood-borne stimuli
- Central chemoreceptors
2. Peripheral chemoreceptors
Where are the central chemoreceptors located
Medulla
Where are the peripheral chemoreceptors located
Aortic arch and common carotid a.
Ventilation increases as a ____ function of increasing PCO2?
linear
The rise in blood _____ ions observed @ the lactate threshold can stimulate ____
H+
ventilation
interaction of both ____ and ___ input to the respiratory control center increases ______ during exercise
neural & chemoreceptors
ventilation
provide the primary drive to breathe during submax exercise
efferent neural mechanisms
provides a means of precisely matching ventilation with amount of co2 produced via metabolism during submax exercise
humural chemoreceptors & neural feedback
pulmonary ventilation/ oxygen consumption
VE/VO2
easily moved (ventilation/respiration)
ventilation
easily exchanged (ventilation/respiration)
respiration
o2 into the blood, co2 into alveoli
external (pulmonary)
o2 into the tissue, co2 into the blood
internal (cellular)
when there is a rise in CO2 there needs to be _____ to ____ ventilation
vasodilation
increase
___ has a greater affinity for o2
hemoglobin
