Pulmonary Flashcards
(116 cards)
Upper airways
nose or mouth: entry point into respiratory system
pharynx: common area used for both respiratory and digestive systems
larynx: connects the pharynx to the trachea, including the epiglottis and vocal cords
lower airways
the conducting airways, trachea to terminal bronchioles, transport air only. No gas exchange occurs.
The respiratory unit: respiratory bronchioles, alveolar ducts, alveolar savs and alveoli. Diffusion of gas occurs through all these structures
R lung
divided into 3 lobes by the oblique and horizontal fissures; each lobe divides into segments- total of 10
L lung
divided into 2 lobes by the oblique fissure; each lobe divides into segments- total of 8
pleura
Parietal pleura covers the inner surface of the thoracic cage, diaphragm and mediastinal border of the lung
visceral pleura: wraps the outside surface of the lung, including the fissure lines
Intracellular space is the potential space between the 2 pleurae that maintains the approximation of the rib cage and lungs, allowing forces to be transmitted from 1 structure to another
primary muscles of inspiration
Primary muscle: diaphragm
- made up of 2 hemidiaphragms, each with a central tendon.
- at rest, the hemidiaphragms are arched high into the thorax
- when the muscle contracts, the central tendon is pulled down, flattening the dome resulting in a protrusion of the abdominal wall during inhalation
Additional primary muscles: portions of the intercostals
Accessory muscles of inspiration
used when a more rapid or deeper inhalation is required or in disease states
upper 2 ribs are raised by the scalenes and SCM
rest of the ribs are are raised by the elevator costar and serrates
by fixing the shoulder girdle- the trap, pecs and serratus can become muscles of inspiration
expiratory muscles of ventilation
resting expiration results from a passive relaxation of the inspiratory muscles and the elastic recoil tendency of the lung
-normal abdominal tone holds the abdominal contents directly under the diaphragm, assisting the return of the diaphragm to the normal high domed position
expiratory muscles are used when a quicker/fuller expiration is desired
-QL, portions of the intercostals, muscles of the abdomen and triangularis sterni
ventilation with patients who lack abdominal musculature (SCI)
have a lower resting position of the diaphragm, decreasing inspiratory reserve
the more upright the body position, the lower the diaphragm and the lower the inspiratory capacity
the more suing the more advantageous the position of the diaphragm
an abdominal binder may be helpful in providing support to the abdominal viscera, assisting ventilation. Care must be taken not to constrict the thorax
Resting end expiratory pressure (REEP)
the point of equilibrium where inspiratory/expiratory forces are balanced
-occurs at end tidal expiration
Forces on the rib cage/breathing mechanics:
- elastic recoil of the lung parenchyma pulls lungs, and bony thorax into a position of exhalation (inward pull)
- bony thorax pulls into a position of inspiration (outward pull)
Tidal volume (TV)
volume of gas inhaled (or exhaled) during a normal resting breath
normal adult: 500mL
normal infant: 20 mL
inspiratory reserve volume (IRV)
volume of gas that can be inhaled beyond a normal resting tidal inhalation
Expiratory reserve volume (ERV)
volume of has that can be exhaled beyond a normal resting tidal expiration
Residual volume (RV)
volume of gas that remains in the lungs after ERV has been exhaled
Inspiratory capacity (IC)
IRV + TV
the amount of air that can be inhaled from REEP
Vital capacity (VC)
IRV + TV + ERV
the amount of air that is under volitional control; conventionally measured as forced expiratory vital capacity (FVC)
Functional residual capacity
ERV + RV
the amount of air that resides in the lungs after a normal resting tidal exhalation
Total lung capacity
IRV + TV + FRV + RV
the total amount of air that is contained within the thorax during a maximum inspiratory effort
Forced expiratory volume (FEV1)
the amount of air exhaled during the 1st second of FVC
in the healthy person, at least 70% of FVC is exhaled within the first second
FEV1/FVC x100 — >70%
ventilation vs. respiration
ventilation= movement of gas in and out of the pulmonary system
respiration= diffusion of gas across the alveolar capillary membrane
arterial oxygenation
=the ability of arterial blood to carry oxygen
PaO2 in the arterial blood
Partial pressure of oxygen in the arterial blood
depends on the integrity of the pulmonary system, the circulatory system and the atmosphere.
95-100% in a young, health person
decreases with age
Hypoxemia 100%
alveolar ventilation
ability to remove CO2 from the pulmonary circulation and maintain pH
pH
indicates the concentration of free floating hydrogen ions within the body
normal range: 7.35-7.45