- *primary purpose of the respiratory system
gas exchange
involves the transfer of oxygen and carbon dioxide between the atmosphere
and the blood
-
... [Show More] **where does gas exchange occur?
the alveolar sacs
- diffusion
O2 and CO2 move back and forth across the alveolar-capillary membrane
how gas exchange takes place
- lower respiratory tract
bronchi
bronchioles
alveolar ducts
alveoli
- upper respiratory tract
nose
mouth
pharynx
adenoids
tonsils
epiglottis
larynx
trachea
- what does the nose do?
warms, cleanses, and humidifies air before it enters the lungs
- how does vocalization occur?
from vibrational sounds that originate in the larynx
- anatomic dead space
the passages where the trachea, bronchi, and bronchioles conduct air to the
alveoli
it is called this because the air is not involved in gas exchange- contraction of the diaphragm (the major muscle of respiration) results in
what?
decreased intrathoracic pressure, which allows air to enter the lungs
- surfactant
a lipoprotein that helps to keep the alveoli open, thus preventing alveolar
collapse
- physiology of respiration
oxygenation
ventilation
inspiration
expiration
- oxygenation
the delivery of oxygen from the atmospheric air to alveolar capillaries and
eventual diffusion into the alveoli
- ventilation
involves inspiration (movement of air into the lungs) and expiration
(movement of air out of the lungs)
- inspiration
breathing in
movement of air into the lungs
active process
involves muscle contration
- expiration
breathing out
movement of air out of the lungs
passive process
when elastic recoil is reduced, expiration becomes a more active, labored
process
- compliance
are they adapting
measure of the ease of expansion of the lungs
when decreased, the lungs are harder to inflate ("stiff lungs")- what does it mean when resistance occurs?
often indicates some type of impairment to air flow into the lungs, such as
narrowed airways or presence of secretions
- *why are arterial blood gases important?
they are the most effective way to measure oxygen status
- ABGs are measured to ...
determine oxygenation status, ventilation status, and acid-base balance
- arterial oxygen saturation monitoring
continuously using a pulse ox. probe
applied to a finger, toe, ear, or bridge of nose
- CO2 monitoring
using transcutaneous carbon dioxide (PtCO2) and end-tidal CO2 (PetCO2)
capnography
PtCO2 is a noninvasive method of estimating PaCO2
PtCO2 is presented as a graph of expiratory CO2 plotted against time
- control of respiration
the respiratory center in the medulla in the brainstem responds to chemical
and mechanical signals from the body
- chemoreceptors
respond to changes in the chemical composition (PaCO2 and pH) of the
fluid around it
- mechanical receptors
stimulated by a variety of physiologic factors, such as irritants, muscle
stretching, and alveolar wall distortion
- respiratory defense mechanisms
filtration of air
- mucociliary clearance system (movement of mucus)
cough reflex: very important; clears the airway by a high-pressure, highvelocity flow of air [Show Less]