Respiratory System Flashcards
What is the main purpose of the cardiopulmonary system?
to deliver oxygen to the tissues and remove
carbon dioxide
What are the functions of respiration?
– Gas exchange: O2 and CO2 exchanged between
blood and air
– Communication: speech and other vocalizations
– Olfaction: sense of smell
– Acid-Base balance: influences pH of body fluids
by eliminating CO2
– Blood pressure regulation: by helping in synthesis
of angiotensin II
– Blood and lymph flow: breathing creates pressure
gradients between thorax and abdomen that
promote flow of lymph and blood
– Blood filtration: lungs filter small clots
– Expulsion of abdominal contents: breath-holding
assists in urination, defecation, and childbirth
(Valsalva maneuver)
What are the principal parts of the respiratory system?
nose, pharynx, larynx,
trachea, bronchi, lungs
Where does the incoming air stop?
alveoli
What does the conducting division do?
– Includes those passages that serve only for airflow
– No gas exchange
– Nostrils through major bronchioles
What does the respiratory division do? What are its divisions?
– Consists of alveoli and other gas exchange regions
* Upper respiratory tract—in head and neck
– Nose through larynx
* Lower respiratory tract—organs of the thorax
– Trachea through lungs
What are the functions of the nose?
– Warms, cleanses, and humidifies inhaled
air
– Detects odors
– Serves as a resonating chamber that
amplifies voice
* Nose extends from nostrils (nares) to
posterior nasal apertures (choanae)—
posterior openings
What are the 3 regions of the pharynx?
nasopharynx, oropharynx, laryngopharynx
What is the function of the larynx?
keep food and drink out of the airway, phonation
What is the epiglottis and what is its function?
flap of tissue that guards the superior
opening of the larynx
– During swallowing, extrinsic muscles of larynx pull
larynx upward
– Tongue pushes epiglottis down to meet it
– Closes airway and directs food to esophagus behind it
– Vestibular folds of the larynx play greater role in
keeping food and drink out of the airway
What are the 9 cartilages of the larynx?
epiglottic, thyroid (adam’s apple), cricoid, artynoid (2), corniculate (2), cuneiform (2)
What are the two folds in the larynx? What is their function?
Superior vestibular folds- close larynx during swallowing
Inferior vocal chords- produce sound
What is the glottis?
the vocal chords and the opening between them
What is loudness determined by?
the force of air passing between vocal chords
What are the features of the trachea?
– Supported by 16 to 20 C-shaped rings of hyaline
cartilage
– Trachealis muscle spans opening in rings
* Inner lining of trachea is ciliated pseudostratified
columnar epithelium
– Mucociliary escalator: mechanism for debris removal (ciliated cells bring upwards)
Middle tracheal layer—connective tissue beneath
the tracheal epithelium
– Contains lymphatic nodules, mucous and serous
glands, and the tracheal cartilages
What is a tracheostomy?
—to make a temporary opening in
the trachea and insert a tube to allow airflow
What makes up the lungs? (basic anatomy)
– Base: broad concave portion resting on diaphragm
– Apex: tip that projects just above the clavicle
– Costal surface: pressed against the ribcage
– Mediastinal surface: faces medially toward the heart
* Hilum—slit through which the lung receives the main
bronchus, blood vessels, lymphatics, and nerves
* These structures near the hilum constitute the root of the
lung
What are the features of the right lung?
- Shorter than left because liver rises higher on the right
- Has three lobes—superior, middle, and inferior—
separated by horizontal and oblique fissure
What are the features of the left lung?
- Tall and narrow because the heart tilts toward the left
and occupies more space on this side of mediastinum - Has indentation—cardiac impression
- Has two lobes—superior and inferior separated by a
single oblique fissure
What is the bronchial tree?
a branching system of air tubes
in each lung
What are the 3 divisions of the bronchi?
main (primary), lobar (secondary), and segmental (tertiary)
What is the end of the conductive division?
terminal bronchioles
What is the order of the lower respiratory tract?
larynx, trachea, main bronchi, lobar bronchi, segmental bronchi, terminal bronchioles
What starts the respiratory division?
respiratory bronchioles
What are the different cell types in the alveoulus?
squamous (type 1), great (type 2), macrophages
What does the respiratory membrane consist of?
squamous alveolar cells, endothelial cells of blood capillary, and the shared basement membrane
What are the types of pleurae?
Visceral pleura—serous membrane that covers lungs
* Parietal pleura—adheres to mediastinum, inner surface of
the rib cage, and superior surface of the diaphragm
What do type 1 cells help with?
rapid gas diffusion
What is the function of the pleurae and pleural fluid?
– Reduce friction
– Create pressure gradient
* Lower pressure than atmospheric pressure; assists lung inflation
– Compartmentalization
* Prevents spread of infection from one organ in mediastinum to
others
What is the difference between quiet and forced respiration?
– Quiet respiration: while at rest, effortless, and automatic
– Forced respiration: deep, rapid breathing, such as during exercise
What are the respiratory muscles?
Diaphragm (prime mover) and intercostals (assists)
What is the valsalva maneuver?
consists of taking a deep
breath, holding it by closing the glottis, and then
contracting the abdominal muscles to raise
abdominal pressure and push organ contents out
– Childbirth, urination, defecation, vomiting
What drives respiration?
atmospheric pressure
What is Boyle’s law?
at a constant temperature, the
pressure of a given quantity of gas is inversely
proportional to its volume
How does Boyle’s law relate to respiration?
– If the lungs contain a quantity of a gas and the lung
volume increases, their internal pressure
(intrapulmonary pressure) falls
* If the pressure falls below atmospheric pressure, air
moves into the lungs
– If the lung volume decreases, intrapulmonary pressure
rises
* If the pressure rises above atmospheric pressure, air
moves out of the lungs
What is the unit for pressure in lungs?
cm H2O
What is intrapleural pressure?
the slightly negative
pressure that exists between the two pleural
layers
What happens to the two pleural layers during inspiration?
they cling together due to the cohesion of water
What is Charles’s law?
volume of a gas is directly
proportional to its absolute temperature
How does Charles’s law relate to respiration?
thermal expansion will contribute to the inflation of
the lungs
What happens in expiration in relaxed and forced breathing?
Relaxed:
– Recoil compresses the lungs
– Volume of thoracic cavity decreases
– Raises intrapulmonary pressure to about 1 cm H2O
– Air flows down the pressure gradient and out of the lungs
Forced:
– Accessory muscles raise intrapulmonary pressure as
high as +40 cm H2O
What is a pneumothorax?
presence of air in pleural cavity, loss of negative pressure allows lungs to recoil and collapse
What does increasing resistance do?
decrease airflow
What two factors influence airway resistance?
bronchiole diameter and pulmonary compliance
What is pulmonary compliance?
ease with which the lungs can
expand
* The change in lung volume relative to a given pressure
change
What is anatomic dead space?
– Conducting division of airway where there is no gas
exchange
What is the tidal volume?
volume of air inhaled and exhaled in one cycle of breathing
What is the IRV?
air in excess of tidal volume that can be inhaled with effort
What is ERV?
air in excess of tidal volume that can be exhaled with effort
What is RV?
air remaining in lungs after max expiration
What is VC? eq?
total amount of air that can be inhaled and then
exhaled with maximum effort
* VC = ERV + TV + IRV
What is IC? eq?
maximum amount of air that can be
inhaled after a normal tidal expiration
* IC = TV + IRV
What is FRC? eq?
amount of air remaining in
lungs after a normal tidal expiration
* FRC = RV + ERV
What is TLC? eq?
maximum amount of air the lungs can
contain
* TLC = RV + VC
What is Dalton’s law?
total atmospheric pressure is the
sum of the contributions of the individual gases
– Partial pressure: the separate contribution of each
gas in a mixture
What is alveolar gas exchange?
the swapping of O2 and
CO2 across the respiratory membrane
What must O2 do to get into the blood?
it must dissolve in
this water, and pass through the respiratory membrane
separating the air from the bloodstream
What must CO2 do to get into the blood?
it must pass the
other way, and then diffuse out of the water film into the
alveolar air
What is Henry’s law?
at the air–water interface, for a
given temperature, the amount of gas that
dissolves in the water is determined by its
solubility in water and its partial pressure in air
How does Henry’s law influence respiration?
Gases diffuse down their own gradients until
the partial pressure of each gas in the air is
equal to its partial pressure in water
Where is PO2 greater? PCO2?
O2= lungs, CO2 = blood
What happens at the alveolus in terms of gas exchange?
unload co2 and load o2
What affects alveolar gas exchange?
solubility of gasses (CO2 more soluble), membrane surface area, membrane thickness
What is gas transport?
the process of carrying gases from
the alveoli to the systemic tissues and vice versa
How is the majority of o2 transported?
bound to hemoglobin
How is the majority of co2 transported?
bicarb in the plasma
How else is co2 transported?
bind to Hb to make carbaminohemoglobin & as dissolved gas
How is CO poisoning dangerous?
competes for O2 binding by making carboxyhemoglobin
What does systemic gas exchange do?
unload O2 and load CO2
What enzyme catalyzes the CO2 reaction?
Carbonic anhydrase
What way does the chloride shift go in systemic gas exchange? Alveolar?
Cl- in, Cl- out
What is the key thing that influences respiration rate?
pH
What monitors pH?
chemoreceptors
What is optimum pH?
7.35 to 7.45
What is the area of the brain that monitors respiration?
medulla oblongata
What does hypocapnia cause?
alkalosis
What does hypercapnia cause?
acidosis
What causes increased respiration during exercise?
stimulating proprioceptors of muscles and joints
What is COPD?
Chronic obstructive pulmonary disease (COPD)—
long-term obstruction of airflow and substantial reduction
in pulmonary ventilation
* Major COPDs are chronic bronchitis and emphysema
What is chronic bronchitis?
– Severe, persistent inflammation of lower respiratory tract
– Goblet cells enlarge and produce excess mucus
– Immobilized cilia fail to remove mucus
– Thick, stagnant mucus – ideal for bacterial growth
– Smoke compromises alveolar macrophage function
– Develop chronic cough to bring up sputum (thick mucus
and cellular debris)
– Symptoms include hypoxemia and cyanosis
What is emphysema?
– Alveolar walls break down
* Lung has fewer and larger spaces
* Much less respiratory membrane for gas exchange
– Lungs fibrotic and less elastic
* Lungs become flabby and cavitated with large spaces
– Air passages collapse
* Obstructs outflow of air
* Air trapped in lungs; person becomes barrel-chested
– Weaken thoracic muscles
* Spend three to four times the amount of energy just to breathe
What are the negative effects of COPD?
COPD causes: hypoxemia, hypercapnia, and
respiratory acidosis
– Hypoxemia stimulates erythropoietin release from
kidneys, and leads to polycythemia
* Cor pulmonale
– Hypertrophy and potential failure of right heart due
to obstruction of pulmonary circulation
