respiratory system Flashcards
functions of the respiratory system
conduction of inspired air, pulmonary ventilation (gas exchange)
what are the main organs involved in the respiratory system
-nose, nasal cavity, paranasal sinuses
-pharynx, larynx, and trachea
-bronchi and their smaller branches
-lungs and alveoli
describe the conducting zone: provide air to the lungs
- main primary bronchi
- lobar bronchi
3.segmental bronchi
describe the components of the respiratory zone: gas exchange
-bronchioles, alveolar ducts, and sacs
nose functions
-airway of respiration
-filtration of inhaled air
-moistening and warming of air
-resonating chamber for speech; tone
-the site of olfactory receptors; smell is only accomplished through the nasal cavity- 1st cranial nerve
paranasal sinuses: functions
-space in the skill filled with air
-lined with mucous membrane: can trap vires but also fill with fluid and cause infections
-lighten the weight of the skull
what is the pharynx
a muscular passageway connecting the nasal and oral cavities superiorly to the larynx and esophagus inferiorly
what are the 3 divisions of the pharynx
-nasopharynx: posterior to the nasal cavity and superior to the oral cavity. only an air passageway, closes during swallowing.
-oropharynx: located posterior to the oral cavity. a common passage for food and air.
-laryngopharynx: behind the larynx, a joint passageway for food and air. continuous with the esophagus and larynx.
describe the structure of the larynx
a framework of 9 cartilages connected by ligaments and membranes
what are the functions of the larynx
-voice production
-open airway
-mechanism of directing air and food into their proper channels- the trachea and esophagus.
what is close to the larynx and helps prevent food and liquids from entering lower respiratory channels.
epiglottis
the larynx is suspended form
the hyoid bone: free floating bone
the larynx is enclosed laterally by
the pharynx
the larynx is inferiorly continuous with the
the trachea
what is the function of the trachea and where does it descend from
wind pipe
-descends from the larynx through the neck and into the mediastinum (space behind the great vessel), where it ends by dividing to the two main (primary bronchi)
main (primary ) bronchi
largest sub divisions, enter the lungs, one on each side
lobar (secondary) bronchi
-3 on right side of the right lung
-2 on left side of the left lung
segmentary (tertiary) bronchi
branch into each lung segment (bronchopulmonary segment) one on each segment
bronchioles
small bronch
branching of the bronchial tree
14 total branches
-main bronchi
-lobar bronchi
-segmentary bronchi
-bronchioles
foreign bodies are more likely to enter the right lung because
it is wider, larger, and runs verticle
bronchopulmonary segment
portion of the lungs that is consistent to each individual, function independently.
what is the respiratory zone
the terminal part of the respiratory tree where gas exchange takes place
where does gas exchange occur?
in the alveoli, pressure pushes oxygen on epithelium and forces gas exchange
-also includes innervation, capillaries and lymphatics around the alveoli
describe the serous membrane of the lungs
-pleura: a double layered sac that surrounds each lung
-parietal pleura: lines the pleural cavities, innermost, inside the body wall
-visceral pleura: covers the lungs
-parietal cavity: space between the parietal and visceral layers of the pleura, where the lungs reside
where is the serous fluid in the pleural cavity?
lies in the inferior portion, lubricates
-the lungs never 100% fill the pleural cavity
right lung
-has 3 lobes and is separated by an oblique and horizontal fissure, larger
left lung
2 lobes, separated by an oblique fissure, cardiac notch: where the hit sits
-the heart sits on the left side, leaving less room for the left lung
the lungs have elastic CT that
acts like a sponge and leaves impressions on the lungs
what are the two phases of ventilation
-inspiration: period when air flows into the lungs
-exhalation: period when gases exit the lungs
during inspiration, increasing the volume by enlarging the dimensions of the thorax does what to air pressure
decreases air pressure within it, causes air to flow inside
air moves from an area of ________ pressure to and area of __________ pressure
-higher
-lower
inspiration
-what happens to the diaphragm?
the diaphragm contracts and moves inferiorly (down), increases V of thoracic cavity
inspiration
-what happens to the external intercostal muscles?
contract to raise the ribs which enlarge both the lateral and the anterior/posterior dimensions. also stiffen the wall
inspiration
-if the wall is not stiffened, the thorax would
just change shape and not increase in volume
inspiration
-dimensions where thoracic volume increases
-vertical dimension (height): diaphragm contract and descends. up and down
-anteroposterior dimension: increases front and back, pump handle movement
-transverse dimension: lateral increase, bucket handle movement
diaphragm structure
skeletal muscle, flat, originates off the body wall, pulls against itself
innervation of the diaphragm
receives somatic motor and sensory innervation from phrenic nerves (C3, C5). centrally, and intercostal nerves peripherally (sensory innvervatin)
blood supply of the diaphragm
from the musculophrenic and pericardiophrenic arteries (branches of the internal thoracic artery
IVC, esophagus, and aorta spatial relationship with the diaphragm
the IVC and esophagus go through the diaphragm
the aorta runs behind, avoid cutting blood flow.
what are the two phases of expiration
-passive expiration
-forced expiration
expiration
-passive expiration
the diaphragm relaxes, moving superiorly while the ribcage drops down slightly, not forceful, external intercostals relax
-relaxation of the external intercostal muscles and the diaphragm decrease volume and increase air pressure
expiration
-forced expiration
the abdominal wall muscles work together to increase intra-abdominal pressure, forcing the diaphragm superiorly. also the muscles of the abdominal wall depress the ribcage, decreasing thoracic volume
expiration
-forced expiration involves
internal intercostal muscles and abdominal muscles
-the abdominal muscles push the organs up
