Flashcards in Respiratory System Deck (112)
Approximately 1L of oxygen is transported to cells each minute. How is most of the body's transported?
bound to Hgb
What usually has a higher pH, venous or arterial blood?
What are the conducting airways of the lower airway?
(no gas exchange occurs here)
What are the respiratory units of the lower airway?
(where gas exchange occurs)
What do Type I alveolar cells do?
Provide structure to the alveoli
What do Type II alveolar cells do?
What is surfactant?
A phospholipid essential to maintain alveolar patency. Decrease surface tension and facilitate gas exchange.
What do the narrow airways in pediatric patients predispose them to?
Increased risk for obstruction and increased resistance to air flow.
At birth newborns have about _____ of alveoli
1/6 to 1/8 the amount an adult has (which is 300mil)
At what age are alveoli matured and increased in size and number by?
What happens to the alveoli in elderly patients?
Reduction of alveolar units
What are the two suppliers of blood supply to the lungs?
Bronchial artery system
Pulmonary artery system (vast network)
What is a normal pulmonary pressure?
What are the functional components of the resp system? (4)
1. Neurochemical control of ventilation
2. Mechanics of breathing
3. Gas transport
4. Control of the pulmonary circulation
Area of neural control of ventilation is located in the:
Medulla and pon (aka resp center)
Which population has the most mucous producing glands?
What stimulates the muscles of inspiration?
Dorsal respiratory group of neurons
How do efferent nerve impulses travel from the brainstem to the diaphragm to stimulate muscle contraction (inspiration)?
via the phrenic nerve
What controls airway lumen diameter?
What do central chemoreceptors respond to?
CO2 and pH (H+ conc)
CO2 crosses BBB and stimulates respiration
What do peripheral chemoreceptors respond to?
Decrease in O2 concentration and decreased pH
The pons apneustic center:
Pattern of respiration
What does the pneumotaxic center of the pons do?
Influences rate of respiration
Inhibits the inspiration (effectively ending it)
How do the baroreceptors in the aortic arch and carotid bodies affect respiration?
When an increased BP is sensed, respiration is decreased
How do proprioreceptors in muscles affect respiration?
Respond to body movement
What are the main muscles of inspiration?
What are the accessory muscles and when are they used?
Used when main muscles are inadequate
What happens when the diaphragm contracts?
It flattens downward, increasing the volume of the thoracic cavity, and creates a negative pressure that draws gas into the lungs through the upper airways and trachea.
What does contraction of the external intercostals do?
Elevates the anterior portion of the ribs. This increases the volume of the thoracic cavity by increasing its front-to-back (anteroposterior [AP]) diameter