Lecture 12 Respiratory System Flashcards
2 types of respiration and meaning
- external = lungs and respiratory system
- internal = aerobic respiration
2 aspects of external respiration
- ventilation = movement of air in and out of lungs
- gas exchange = transfer of gasses between blood and air
flow of air through respiratory structures
- mouth and nose –> trachea –> bronchus –> right and left bronchus –> terminal bronchioles –> respiratory bronchioles –> alveolar sacs –> alveoli
lining of upper airways vs lower airways
upper airways: psueudostratified ciliated columnar epithelium that moves mucus which catches debir
- lower airways = squamous endothelial cells good for gas diffusion
alveolar cells type 1 vs type 2
- type 1 lines alveoli
- type 2 produces surfactant
respiratory / pulmonary membrane and 3 parts
- fused membrane, connective tissue
- alveolar type 1 cells
- endothelial cells lining the capillaries
ARDS - causes, treatment, and effects
- acute respiratory diseases syndrome
- inflammation and excess fluid in lungs –> reduced surface area for gas exchange
- respiratory membrane is damaged by inflammation
- increased O2 in lung will not help since gas exchange will not occur
- also caused by drowning and sepsis
2 zones of respiratory system and description
- conducting zone aka dead zone, no gas exchange
- respiratory zone, lower airways, gas exchange occurs
describe intrapleural space and structures
- parietal pleura connected to thoracic cavity
- visceral pleura attached to lungs
- serous fluid in between creates hydrogen bonds that attaches the 2 pleura
- intrapleural space is not a real space but can be filled with water/air/pus/blood
pneumothrax, hemothorax, and thoracic empyema
- pneumothorax = air
- hemothorax = blood
- thoracic empyema = pus
negative interpleural pressure
pressure in interpleural space is always negative to keep lungs from collapsing
negative vs positive pressure in lungs - when generated
- negative pressure during inhalation, air comes in
- positive pressure during exhalation, air leaves
inhalation - changes in volume and pressure
diaphragm contracts and moves down, volume increases, pressure decreases, air enters
exhalation - changes in volume and pressure
diaphragm relaxes and moves up, volume decrease, pressure increases, air moves out
transmural pressure aka transpulmonary pressure
- always positive
- think of as force that pulls lungs out and keeps them from collapsing
- intrapulmonary pressure - interpleural pressure
compliance, how measured
- how easily lungs can expand
- change in volume / change in pressure
elasticity and cause
- caused by elastin fibers in stroma (connective tissue surrounding alveoli)
- ability of lungs to recoil
surface tension effect and cause
- caused by fluid produced by alveolar cells type 1
- pulls alveoli in towards collapsing due to hydrogen bonds of the fluid
surfactant cause and effect
- produced by alveolar type 2 cells
- breaks up the hydrogen bonds of the fluid and keeps alveoli from collapsing
factors favoring elasticity
- elastin
- surface tension
factors favoring compliance
- surfactant
- intrapleural pressure
RDS cause and treatment
- respiratory distress syndrome
- in premes because surfactants are not created
until the last few weeks of gestation - CPAP = continuous positive airway pressure to keep lungs open
muscles in normal breathing
- diaphragm doing 70% of work
- parasternal and external intercostal muscle to expand chest out
forced inhalation accessory muscles
- sternocleidomastoid
- pectoralis minor
- scalene
forced exhalation muscles used
- internal intercostal muscle
- abdominal muscle
spirometry
method for measuring pulmonary functioning
tidal volume
volume inhaled/exhaled during normal breathing, very small, 300-500mL
inspiratory reserve volume
- volume of air inhaled during forced inhalation
- 3L
- does not include tidal volume
expiratory reserve volume
- max volume of air exhaled during forced exhalation
- 1L
- does not include tidal volume
forced vital capacity FVC
IRV + ERV + TV
- max air in lungs - min air ini lungs during forced inhalation and exhalation
total lung capacity
- max volume of air in lungs
- includes 1L of residual volume
FEV1
- max amount of air exhaled during forced exhalation
functional residual capacity
- ERV + residual volume
- volume in lungs after normal exhalation
inspiratory capacity
- max amount of air that can be inhaled after normal expiration
residual volume
1L
- volume of air always in lungs
FEV1 test, reading, metrics and results
- read right to left
- calculated as a percentage with normal = 80%
- FEV1/FVC is a useful metric
apnea
lack of breathing
- think sleep apnea
dyspnea
labored breathing
eupnea
normal breathing
hyperventilation - CO2 levels and 2 characterizations
low CO2 levels
- tachypnea - fast breathing
- hyperpnea = deep breathing
tachypnea
fast breathing
hyperpnea
deep breathing
kussmal breathing - cause and characterization
- due to diabetic ketoacidosis
- both tachypnea and hyperpnea
hypoventilation - CO2 levels
- high Co2 levels
- slow and shallow breathing
normal breathing rate
10-12 breaths / minute
atelectasis
collapse of lungs
obstructive disorders - exhalation/inhalation harder, main symptoms, 2 main examples, effect on FEV, FVC, and FEV/FVC ratio
- exhalation harder since there is a lot of inflammation and constriction and lungs must constrict during exhalation
- COPD and asthma
- normal FVC but low FEV< thus low FEV/FVC ratio
- inflammation, bronchioconstriction, airwasy narrowed, collapsed, or obstructed
restrictive disorders - effect on FEV, FVC, and FEV/FVC ration, main example
- harder to inhale, like typing a belt around your chest
- low FVC and normal FEV = high FEV/FVC ration
- pulmonary fibrosis
asthma
- 2 class of drugs
- main symptom and is exhalation/inhalation harder
- type of disorder
- cause
- wheezing during exhalation
- obstructive, exhalation is harder
- inflammation often due to allergies = atopic asthma and airway hyperresponsiveness
- bronchiodilators = inhibitory, beta 2 receptor agonists
- corticosteroids that are antiinflammatory
emphysema
- type of disorder
- effect on lungs and how its leads to inhalation/exhalation harder
- obstructive, exhalation harder
- caused by smoking
- inflammation and alveoli destruction –> larger alveoli.
- based on laplace law: less surface tension and less pressure makes it harder to exhale
COPD
- type of disorder
- main effects
- 2 related disorders
- emphysema and chronic bronchitis
- alveolar destructions, inflammation, narrowing of airways
cor pulmonale
- COPED –> blood vessels in lungs have more resistance –> pulmonary hypertension –> right heart hypertrophy –> right ventricular failure
bronchitis and emphysema - ways to remember
- bronchitis = blue bolus, blue because low O2, barrel chested because hard to exhale
- emphysema = pink pucker, pursed lips and hunched over to make exhalation easier, pin because well oxygenated
pulmonary fibrosis
- effects
- type of disorder
- 3 types / causes
- more collage in stroma of lungs, less compliant
- harder to inhale, restrictive
- asbestosis, silicosis, anthracosis
law of laplace - pressure, surface tension, and radius
- increase surface tension = increased pressure
- smaller radius = increased pressure
law of laplace and size of alveoli
- larger alveoli (due to emphysema) have lower pressure making it harder to exhale
