Chapter 23 - The Respiratory System - REVIEW Flashcards
What does surfactant do?
helps prevent the alveoli from collapsing
the hard palate separates the….
nasal cavity and oral cavity
WHY does air move into the lungs?
because the gas pressure in the lungs is less than the atmospheric pressure
Explain what occurs during a cough
the glottis closes partway through exhalation. The abdominal and internal intercostal muscles contract suddenly, creating pressure that blasts air out of the respiratory passages
What happens when the diaphragm and external intercostal muscles contract?
intrapleural pressure decreases
During the winter, Brad sleeps in a dorm room that lacks any humidifier for the heated air. In the mornings, he notices that his nose is “stuffy”, but after showering and drinking water, the stuffiness disappears until the next morning. what might be the cause of Brad’s nasal condition?
Since the air brad is breathing is dry, large amounts of moisture are leaving the mucus in his respiratory tract to humidify the inhaled air. Drying makes the mucus tacky and makes it difficult for the cilia to move, so mucus builds up, producing nasal congestion by morning. When Brad showers and drinks fluids, body water is replaces, so the mucus loosens up and can be moved along as usual
Distinguish the structures of the upper respiratory system from those of the lower respiratory system
upper respiratory system - paranasal sinuses, nasal cavity, nose, pharynx
lower respiratory system - larynx, trachea, bronchus, bronchioles, alveoli of the lungs
Name the 3 regions of the pharynx. Where is each region located?
nasopharynx-superior
oropharynx-middle
laryngopharynx-inferior
What 3 integrated steps are involved in external respiration
- Breathing (pulmonary ventilation)
- diffusion of gases across respiratory membrane and between blood and interstitial fluids
- Transport of O2 and CO2 between alveolar and peripheral capillaries
What important physiological differences exist between fetal hemoglobin and maternal hemoglobin?
Fetal hemoglobin has a higher affinity for oxygen. Thus, it binds more of the oxygen that is present, enabling it to “steal” oxygen from maternal hemoglobin
By what 3 ways is carbon dioxide transported in the bloodstream?
- As carbonic acid
- Dissolved in plasma
- Binds to hemoglobin
Give 3 reasons why gas exchange at the respiratory membrane is efficient
- The differences in partial pressure are substantial
- The gases are lipid soluble
- The total surface area is large
Explain what is happening in internal respiration
-oxygen is diffusing from the blood into interstitial fluid
-carbon dioxide is diffusing from the interstitial fluid to the blood
-bicarbonate ions are formed in red blood cells
-chloride ions diffuse into red blood cells as bicarbonate ions diffuse out
T/F
hemoglobin binds more oxygen during internal respiration
false
If the concentration of 2,3-bisphosphoglycerate (BPG) increases, what will happen?
the amount of oxygen released by hemoglobin will increase
An increase in the partial pressure of carbon dioxide in arterial blood causes chemoreceptors to stimulate the respiratory centers, resulting in….
an increased respiratory rate
Why is breathing through the nasal cavity more desirable than breathing through the mouth?
The nasal cavity cleanses, moistens, and warms inhaled air while the mouth does not. Drier air entering through the mouth can irritate the trachea and cause throat soreness
How would you justify the statement:
“The bronchioles are to the respiratory system as to the arterioles to the cardiovascular system”
smooth muscle tissue in the walls of bronchioles allows changes in airway diameter which provides control of the flow and distribution of air within the lungs, just as vasodilation and vasoconstriction of the arterioles control blood flow and blood distribution
How are pneumocytes type 2 involved with keeping the alveoli from collapsing?
pneumocytes type 2 (septal cells) produce surfactant, which reduces surface tension in the fluid coating the alveolar surface. Without surfactant, the surface tension would be so high that the delicate alveoli would collapse
pneumocytes type 2 are also known as..
septal cells
How does pulmonary ventilation differ from alveolar ventilation, and what is the function of each type of ventilation?
Pulmonary ventilation is the physical movement of air into and out of the respiratory tract and helps to maintain adequate alveolar ventilation
Alveolar ventilation is air movement into and out of the alveoli and prevents the buildup of CO2 in the alveoli and ensures a continuous supply of oxygen that keeps pace with absorption by the bloodstream
What is the significance of Boyle’s law to the process of respiration?
Boyle’s law describes the inverse relationship between gas pressure and volume. It is the basis for the direction of air movement in pulmonary ventilation
What is the significance of Dalton’s law in the process of respiration?
Each of the gases that make up a mixture of gases contributes to the total pressure in proportion to its relative abundance/ that is, all the partial pressures added together = the total pressure exerted by the gas mixture.
This is the basis for the calculation of the partial pressures of oxygen and carbon dioxide, and their exchange between blood and alveolar air
What is the significance of Henry’s law in the process of respiration?
at a given temp, the amount of a particular gas that dissolves in liquid is directly proportional to the partial pressure of that gas
this law underlies the diffusion of gases between capillaries, alveoli, and interstitial fluid
What happens to the process of respiration when a person is sneezing or coughing?
both sneezing and coughing involve a temporary cessation of respiration, known as APNEA
What is the functional difference between the dorsal respiratory group (DRG) and ventral respiratory group (VRG) of the medulla oblongata
DRG
-inspiratory center that contains neurons that control lower motor neurons innervating the external intercostal muscles and the diaphragm. FUNCTIONS IN EVERY RESPIRATORY CYCLE, WHETHER QUIET OR FORCED
VRG
-only functions during FORCED respiration–active exhalation and maximum inhalation. The neurons involved with active exhalation are sometimes said to form an expiratory center
MR B has had chronic advanced emphysema for 15 years. while hospitalized with a respiratory infection, he goes into respiratory distress. without thinking, his nurse administers pure oxygen which causes him to stop breathing. why?
a person with chronic emphysema has constantly elevated blood levels of PCO2 due to an inability to eliminate CO2 efficiently because of physical damage to the lungs. Over time, the brain ignores the stimulatory signals produced by the increased CO2 and begins to rely on information from peripheral chemoreceptors to set the pace of breathing (accomodation) The peripheral chemoreceptors also accomodate to elevated CO2 and respond primarily to the low level of O2 in the blood, increasing breathing when O2 levels are low and decreasing breathing when O2 levels are high.
When pure O2 was administered, chemoreceptors responded with fewer action potentials to the medulla oblongata, so mr b stopped breathing
Someone hyperventilates for several minutes before diving into a swimming pool. After he enters and begins swimming for a few minutes, he blacks out. What causes this to happen?
the hyperventilation caused abnormally low PCO2. This reduced his urge to breathe, so he stayed underwater longer, unaware that is PO2 was dropping to the point of loss of consciousness
Why do individuals who are anemic generally not exhibit an increase in respiratory rate or tidal volume, even though their blood is not carrying enough oxygen?
in anemia, the blood’s ability to carry oxygen is decreased due to lack of functional hemoglobin, red blood cells, or both.
Anemia does not interfere with the exchange of carbon dioxide within the alveoli, nor with the amount of oxygen that will dissolve in the plasma.
Because chemoreceptors respond to dissolved gases and pH, as long as they are normal, ventilation patterns should not change significatnyl
Doris has an obstruction of her right primary bronchus. How would you expect her oxygen-hemoglobin saturation curve for her right lung to compare with that of her left?
The obstruction would prevent gas exchange. Thus, the blood moving through the right lung would not be oxygenated and would retain carbon dioxide, which would lead to a lower blood pH than the left lung. The lower pH would shift the curve to the left (Bohr effect)
