Exam 2_Respiratory Flashcards
What is ventilation?
movement of air in and out of lungs
What is gas exchange?
Diffusion of O2 and CO2 between alveoli in lung and the blood
What is perfusion?
movement of blood into and out of the capillary beds.
What is transport?
movement of O2 and CO2 via blood and circulatory system
What structures make up the extra-thoracic cavity?
nose
pharynx
larynx
trachea
What structures make up the intra thoracic cavity?
trachea
bronchi
bronchioles
What lines the respiratory passage?
- goblet cell-secrete mucous
2. cilia-clear debris from airways and keep airways moist
Vocal cords are ______ during breathing
open
Vocal cords are _______ during phonation
closed
What does the epiglottis due in adults that it does not in infants?
flaps during eating to block airways
Bronchioles do not have _______ but the trachea and bronchi do.
Bronchioles do not have cartilage and depend on transpulmonary pressure to remain open. It has smooth muscle instead of cartilage.
Respiratory smooth muscle is innervated by what nerve fibers?
- sympathetic nerve fibers that act on beta 2 receptors to relax smooth muscle
- parasympathetic nerve fibers that come from the vagus nerve
What does epinepherine do?
causes relaxation of smooth muscle and bronchodilation
What do parasympathetic nerve fibers secrete?
acetylcholine which causes contraction of bronchiolar smooth muscle and bronchoconstriction.
What do Leukotrienes do?
constrict
What do histamine and substance from mast cells (anaphylaxis) do?
constrict
How many lobes make the right lung and left?
Right-3
Left-2
What makes up the respiratory zone?
terminal bronchioles
alveoli
alveolar capillaries
Pores of Kohn and Canal of Lambert
- channels between alveoli to allow communication
- implicated in alveolar disease and ease of spread of pulmonary infections
What is surfactant?
Coats inner alveoli and allows expansion during inhalation and prevents alveolar collapse on exhalation
What happens with the diameter of the conducting zone decreases?
- there is an increase in resistance
* a 1mm change in airway diameter due to edema results in 81% of adult airway remaining patent vs 44% in a neonate
What does the diaphragm do?
- adjust the size of the chest cavity
- contraction pulls lungs down during inhalation
- relaxation/elastic recoil moves lungs up during exhalation, forced exhalation uses abdominal muscles to push lungs up
What do intercostal muscles do?
- External intercostals: raise and expand rib cage with help of sternocleidomastoid muscles on inhalation
- Internal intercostals and abd recti: pull rib cage down and in during exhalation
What is the pleura and what is it made of?
-tissue lining of the lungs and rib cage
- visceral pleura-connected to lungs
- parietal pleura- connected to rib cage
What is between the pleural spaces?
pleural fluid
What kind of pressure causes the lung to move with the rib cage?
Negative pressure
What pressures changes move air?
- Pleural pressure
- Alveolar presssure
- Transpulmonary pressure
Pleural Pressure
Normall -5cm H2O, when chest expands decreases to -7.5 cm H2O which increases suction forces pulling lungs with rib cage
Alveolar Pressure
pressure in alveoli = pressure in respiratory tree when glottis is open = atmospheric pressure = 0 cm H2O
What happens when the chest wall expands?
Alveoloar pressure decrease to -1cm H2O and air moves in
What happens when the chest recoils?
Alveolar pressure increase to +1 cm H2O and air moves out
Transpulmonary Pressure
Pressure difference between pleural and alveolar pressure
*elastic forces that cause lung collapse at the end of exhalation are counteracted by PEEP, surfactant, and close glottis
What happens if the pressure inside and outside of the lungs is the same?
It will collapse
-can be caused by asthma or trauma
What is compliance?
degree lungs expand per unit of change in transpulmonary pressure
**how much air can you get in vs how much pressure you can give
Compliance is determined by:
elastic forces in lung tissue and elastic forces of pleural tension in alveoli and lung interstitum
What is surface tension elastic force?
air fluid interface creates a force that cause alveoli to collapse inward
What does surfactant do to the surface tension?
Reduces it and it disrupts the water molecules
What could cause decreased compliance?
Bronchitits, PNA, COPD
Difference between adult and children rib cages?
Adult is rigid and needs more effort to expand and chest wall has limited recoil.
Children have cartilaginous ribs which makes it easier to expand and has a strong recoil but more potential for collapse during exhalation
When is more muscular effect need for breathing?
- lung compliance is decreased (pulmonary edema or infection)
- chest wall compliance (scoliosis or obesity)
- airways are obstructed (bronchospasm or mucous plugging)
What is tidal volume?
volume of inspired and expired air with each normal breath
What is inspiratory reserve volume?
maximum extra volume of air that can be inspired at the end of a normal tidal volume
What is expiratory reserve volume?
max extra volume of air that can be expired at the end of normal tidal volume
What is residual volume?
the volume of air that remains in the lungs at then end of a forceful exhalation
What is inspiratory capacity?
tidal volume + inspiratory reserve volume
What is functional residual capacity?
expiratory reserve volume + residual volume (the amount of air that remains at the end of normal exhalation)
What is vital capacity?
inspiratory reserve volume + tidal volume + expiratory reserve volume (max volume that can be exhaled after max inhale)
What is total lung capacity?
vital capacity + residual volume (max volume lung can be expanded)
Minute ventilation
total amount of new air moved into the respiratory system each minute
What is alveolar ventilation?
- Rate new air reaches the gas exchange areas of the lungs
- Where gas exchange happens
What is dead space?
space in respiratory system where there is no gas exchange
Where can you find a dead space?
places where alveoli do not have any blood flow
Route of pulmonary circulation
RV»_space; Pulmonary Artery»_space; Pulmonary capillary bed (where gas is exchanged)»_space; pulmonary vein»_space; LA
What do bronchial vessels do?
provide oxygenated blood to trachea, bronchi, lungs, espophagus, visceral pleural and pulmonary arteries
** does not contribute to gas exchange
What happens during the hypoxic pulmonary vasoconstriction response?
Results in increased pulmonary vascular resistance in the lung unit that is not well ventilated which leads to shunting of pulmonary blood flow to areas of the lung that are adequately ventilated
What is V/Q mismatch?
Ventilation perfusion mismatch or V/Q defects are defects in the total lung ventilation/perfusion ratio. It is a condition in which one or more areas of the lung receive oxygen but no blood flow, or they receive blood flow but no oxygen.