167 - finish Flashcards
Pressure inside a spherical (curved) surface is inversely proportional to its radius
Law of Laplace
This explains why smaller alveoli have higher pressure (more to overcome)
Like blowing up a smaller balloon vs a bigger one
Law of Laplace
P=2T/r
P = pressure T = tension r = radius
Law of Laplace
Premature newborns born before their lungs have the capability of producing surfactant
Without surfactant, alveoli collapse much easier
This causes a reduction in breathing capability
Usually enough production by ~ week 35
Respiratory Distress Syndrome (RDS)
Partial or complete collapse of the lung
Atelectasis
Anything that causes alveoli to collapse
Being ventilated (sometimes even during surgery)
Constrictive pressure (garments, pleural effusions)
Pneumonia
Neuromuscular diseases (unable to take full breath)
Atelectasis
A measure of how much effort is required to stretch the lungs and chest wall
Compliance of the Lungs
lungs and chest wall expand easily
High Compliance
lungs and chest wall resist expansion
Low Compliance
Compliance determined by elasticity and surface tension
Lungs normally have high compliance due to elastic fibers in lung tissue and ____ in surface tension
Surfactant
Walls of airways (especially _____) offer resistance to airflow in and out of lungs
Bronchioles
As lungs expand during inhalation, airway walls are pulled outward, enlarging the ___, decreasing resistance
Lumen
As lungs recoil during exhalation, airway walls return to normal size, shrinking the lumen, increasing ____
Resistance
Airway Resistance:
Also regulated by degree of contraction/relaxation of ____ muscle in walls of airways
smooth
Normal pattern for quiet breathing
Can consist of shallow, deep, or combined breathing
Eupnea
Pattern of shallow (chest) breathing
Upward and outward movement of chest due to contraction of external intercostal muscles
Costal Breathing
Pattern of deep breathing
Consists of outward movement of abdomen due to constriction and descent of diaphragm
Diaphragmatic Breathing
Respirations provide humans with methods for expressing emotions such as:
Laughing
Sighing
Sobbing
Respiratory movements can be modified and controlled during talking and singing
Modified Respiratory Movements
Stimulated by foreign matter in trachea or bronchi irritating mucosal lining/cilia
Epiglottis and glottis close + contraction of expiratory muscles = increased air pressure in lungs
Epiglottis and glottis open rapidly which causes a burst of pressurized air to be expelled quickly
Cough Reflex
Similar to cough reflex
Only difference is that it’s stimulated by irritants in the nasal cavity
Droplets from a sneeze can travel 100mph and as far as 12 ft
Sneeze Reflex
Involuntary, spasmodic contraction of the diaphragm
Usually occurs during inhalation which abruptly closes the glottis which causes the characteristic sound
Hiccup
Apparatus used to measure volume of air exchanged during breathing and the respiratory rate
Spirometer/Respirometer
Spirometer/Respirometer
The record of this is called a ____
Spirogram
Spirogram:
Inhalation is recorded as an ____ deflection
Exhalation is recorded as a ____ deflection
Inhale - Upward
Exhale - Down