Respiratory Flashcards
describe the functions of the respiratory system
main function is respiration; provides body cells with oxygen and removes waste product carbon dioxide; includes pulmonary ventilation, pulmonary gas exchange, gas transport, and tissue gas exchange
describe how pressure and volume apply to pulmonary ventilation (negative pressure)
pressure-volume relationship provides driving force for pulmonary ventilation
air is a mixture of gas molecules
Boyle’s law states that at constant temperature and number of gas molecules, pressure and volume of gas are inversely related; hence as volume increases, pressure decreases and vice versa
describe the mechanics of inspiration and expiration
inspiration (inhalation) brings air into the lungs
expiration (exhalation) moves air out of the lungs
describe and distinguish between pulmonary volume and capacities
pulmonary volumes - measuring volumes of air that person exchanges with each breath
tidal volume - amount of air inspired or expired during normal quiet ventilation
inspiratory reserve volume - volume of air that can be forcibly inspired after normal tidal volume inspiration
expiratory reserve volume - amount of air that can be forcibly expired after normal tidal volume expiration
residual volume - air remaining in lungs after forceful expiration
pulmonary capacities:
vital capacity - total amount of exchangeable air
total lung capacity - represents total amount of exchangeable and nonexchangeable air in lungs
describe how oxygen and carbon dioxide pressure gradients lead to net gas exchange in the lungs and tissues
during pulmonary gas exchange, oxygen diffuses from air in alveoli to blood in pulmonary capillaries, and carbon dioxide flows in opposite direction
as with movement of all gases, pulmonary gas exchange is driven by pressure gradients created by difference in partial pressures of oxygen and carbon dioxide between air in alveoli and blood in pulmonary capillaries
Dalton’s law - each gas in mixture exerts its own pressure; total pressure of gas mixture is the sum of partial pressures of all its component gases; partial pressure of gas in mixture determines where gas diffuses; rate of gas diffusion is determined by steepness of pressure gradient
Henry’s law - degree to which gas dissolves in liquid is proportional to both partial pressure and solubility in liquid; explains behavior of gases in air that come in contact with water in body
tissue gas exchange is the exchange of oxygen and carbon dioxide between blood and tissues; partial pressure of oxygen and carbon dioxide in systemic capillaries and tissues provide pressure gradients that drive diffusion of gases
describe mechanisms by which oxygen and carbon dioxide are carried in the blood and released for exchange
carbon dioxide - blood plasma, carbaminohemoglobin, and bicarbonate ions
oxygen - hemoglobin
explain and describe diseases of the respiratory system
restrictive: decrease pulmonary compliance and reduce effectiveness of inspiration by increasing alveolar surface tension and destroying elastic tissue of lungs
obstructive: increase airway resistance and decreases efficiency of expiration; traps oxygen-poor, carbon dioxide-rich air in alveoli; can lead to collapse of airways
functions of nose and nasal cavity
inhaled air is warmed and humidified, debris is filtered from inhaled air, antibacterial substances are secreted, olfactory receptors are housed, and enhances resonance of voice
describe the pharynx
throat; nasopharynx, oropharynx, and laryngopharynx
describe the epiglottis
tip of the larynx
describe the larynx
voice box; houses vocal chords; keeps food and liquids out of the remaining respiratory tract; thyroid cartilage forms shield-like anterior and superior walls of larynx; cricoid cartilage is used for emergency airway; arytenoid cartilage is involved in the sound production and are attached to the vocal chords and intrinsic muscles of larynx; corniculate cartilage are the tiny pieces capping each arytenoid and also function in sound production; cuneiform cartilage help support epiglottis in lateral walls of larynx; vestibular folds are false vocal chords that play no role in sound production; vocal ligaments are the elastic bands at the core of vocal cords and vibrate to produce sound when air passes over them
describe the uvula
part of soft palate; dangly thing that triggers gag reflex
describe glottis
opening through which air can travel on its way to the lungs
distinguish between loudness and pitch
sound loudness is determined by force of airstream; greater force of expiration = louder sound
pitch of sound is largely determined by tension of vocal cords and speed of vibration
describe the trachea
windpipe
carina is the last tracheal cartilage ring that forms “hook” that curves down and back to form partial rings that surround first branches of bronchial tree
describe the bronchial tree
primary bronchi (left or right) is the beginning of bronchial tree and divide at the carina
secondary bronchi is branched from primary; 3 on right and 2 on left
bronchioles are the smallest airways
alveolar sacs are grapelike clusters of alveoli at the end of the duct and its where inspired air has arrived where gas exchange occurs
passageway of air
nares – nasal cavity – nasopharynx – oropharynx – laryngopharynx – larynx – trachea – primary bronchi – secondary bronchi – tertiary bronchi – multiple branches of bronchi – bronchioles – terminal bronchioles – respiratory bronchioles – alveolar ducts – alveolar sacs
discuss the 3 alveoli cell types
type 1: squamous cells that account for about 90% of cells in alveolar wall; allow for rapid diffusion of gases across cell membranes; one of the three components of respiratory membrane
type 2: small cuboidal cells that account for about 10% of cells in alveolar wall; responsible for synthesis of surfactant
alveolar macrophages: mobile phagocytes; clean up and digest debris that made its way into the alveolus
describe the lungs
right lung has 3 lobes and left lung only has 2 lobes due to space for heart
hilum is the triangular depression on mediastinal surface of each lung where primary bronchi, blood and lymphatic vessels, and nerves enter and exit the lung
parietal pleura is the outer layer of serous membrane
visceral pleura is the inner layer of membrane and is continuous with the surface of the lungs
describe pulmonary ventilation
between breaths: intrapulmonary pressure equals atmospheric pressure, so no air movement occurs
inspiration: inspiratory muscles contract; thoracic and lung volumes increase; intrapulmonary pressure decreases to below atmospheric pressure, so air flows into the lungs
between inspiration and expiration: intrapulmonary pressure equals atmospheric pressure, so no air movement occurs
expiration: inspiratory muscles relax; thoracic and lung volumes decrease due to elastic recoil; intrapulmonary pressure increases to above atmospheric pressure, so air flows out of the lungs
what is the big picture of respiration
pulmonary ventilation: oxygen and carbon dioxide are moved between the air and the alveoli in the lungs
pulmonary gas exchange: oxygen enters and carbon dioxide exits the blood via the alveoli
gas transport: oxygen and carbon dioxide are transported by the blood
tissue gas exchange: oxygen and carbon dioxide are exchanged between the blood and the tissue cells
