Respiratory System Flashcards
Pathway of air flow
air enters nasal cavity-pharynx-larynx-trachea-bronchi-bronchioles-alveoli
surfactant
detergent that lowers surface tension and prevents alveoli in lungs from collapsing
Pleura
Visceral-inner layer; parietal-outer; intrapleural space-between visceral and parietal pleurae, contains fluid which lubricates 2 pleural surfaces
Inhalation muscles
contraction of diaphragm and external intercostal muscles, which expand thoracic cavity
Process of inhalation
- chest wall expands outward-volume of intrapleural space increases
- increase volume, decrease pressure in intrapleural
- gas in lungs @ atmospheric pressure; now higher than intrapleural space
- lungs expand, pressure drops; air sucked in from outsdie which has higher pressure
Driving force of inhalation
lower pressure in intrapleural space compared to the lungs
Exhalation process
- chest cavity volume decreases
- pressure in intrapleural space increase
- pressure intrapleural> pressure lungs
- lungs recoil, colume decreases, pressure increases
- exhalation of air to decrease pressure
spirometer
measures lung capacity and volume
Total Lung Capacity
max volume air in lungs when one inhales
Residual Volume
min volume air in lungs after exhaling
Vital Capacity
TLC-RV
difference between max and min volume of air
Tidal Volume
volume of air inhaled and exhaled in normal breath
Expiratory Reserve Volume
volume of additional air that can be forcibly exhaled after normal exhalation
Inspiratory Reserve Volume
volume of additional air that can forcibly be inhaled after normal inhalation
Ventilation center
collection of neurons in medulla oblongata that regulate ventilation; fire regularly to cause regular contraction of respiratory muscles
Chemoreceptors
contained in ventilation center neurons; sensitive to carbon dioxide concentration; when pressure of CO2 increases,respiration rate increases so more CO2 will be exhaled
Hypoventilation
leads to high CO2 levels; medullar oblongata inditiates increased breathing
Hyperventilation
leads to low CO2 levels; can inhibit ventilation to ration CO2
Driving force of gas exchange in alveoli
pressure differentials of gases; blood from heart has low pressure of O2, so O2 diffuses from alveoli into blood; blood from heart has high CO2 so diffuses into alveoli
Thermoregulation
body temp regulated through vasodilation and vasoconstriction; when capillaries expand, more blood passes through and more thermal energy use; when contract, heat conserved
Immune function of lungs
large vasculature of lungs provides threat of pathogens entering body
1st line of defense
small hairs in nasal cavity that trap infectious particles; lysozyme enzyme in nasal cavity that attacks peptidoglycan walls of bacteria
2nd line:
internal airways lined with mucus which traps larger invaders. cilia propels mucus out into oral cavity to be expelled or swallowed. known as musociliary excalator
Immune cells in lungs
Macrophages: engulf and digest pathogens, signal to immune system of invader
IgA antibodies: protect against pathogens
Mast cells: release inflammatory chemicals to promote immune response