Chapter 23 - The Respiratory System - REVIEW

Question 1

What does surfactant do?

Answer 1

helps prevent the alveoli from collapsing

Question 2

the hard palate separates the….

Answer 2

nasal cavity and oral cavity

Question 3

WHY does air move into the lungs?

Answer 3

because the gas pressure in the lungs is less than the atmospheric pressure

Question 4

Explain what occurs during a cough

Answer 4

the glottis closes partway through exhalation. The abdominal and internal intercostal muscles contract suddenly, creating pressure that blasts air out of the respiratory passages

Question 5

What happens when the diaphragm and external intercostal muscles contract?

Answer 5

intrapleural pressure decreases

Question 6

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?

Answer 6

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

Question 7

Distinguish the structures of the upper respiratory system from those of the lower respiratory system

Answer 7

upper respiratory system - paranasal sinuses, nasal cavity, nose, pharynx

lower respiratory system - larynx, trachea, bronchus, bronchioles, alveoli of the lungs

Question 8

Name the 3 regions of the pharynx. Where is each region located?

Answer 8

nasopharynx-superior
oropharynx-middle
laryngopharynx-inferior

Question 9

What 3 integrated steps are involved in external respiration

Answer 9

1. Breathing (pulmonary ventilation)
2. diffusion of gases across respiratory membrane and between blood and interstitial fluids
3. Transport of O2 and CO2 between alveolar and peripheral capillaries

Question 10

What important physiological differences exist between fetal hemoglobin and maternal hemoglobin?

Answer 10

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

Question 11

By what 3 ways is carbon dioxide transported in the bloodstream?

Answer 11

1. As carbonic acid
2. Dissolved in plasma
3. Binds to hemoglobin

Question 12

Give 3 reasons why gas exchange at the respiratory membrane is efficient

Answer 12

1. The differences in partial pressure are substantial
2. The gases are lipid soluble
3. The total surface area is large

Question 13

Explain what is happening in internal respiration

Answer 13

-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

Question 14

T/F
hemoglobin binds more oxygen during internal respiration

Answer 14

false

Question 15

If the concentration of 2,3-bisphosphoglycerate (BPG) increases, what will happen?

Answer 15

the amount of oxygen released by hemoglobin will increase

Question 16

An increase in the partial pressure of carbon dioxide in arterial blood causes chemoreceptors to stimulate the respiratory centers, resulting in….

Answer 16

an increased respiratory rate

Question 17

Why is breathing through the nasal cavity more desirable than breathing through the mouth?

Answer 17

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

Question 18

How would you justify the statement:
“The bronchioles are to the respiratory system as to the arterioles to the cardiovascular system”

Answer 18

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

Question 19

How are pneumocytes type 2 involved with keeping the alveoli from collapsing?

Answer 19

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

Question 20

pneumocytes type 2 are also known as..

Answer 20

septal cells

Question 21

How does pulmonary ventilation differ from alveolar ventilation, and what is the function of each type of ventilation?

Answer 21

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

Question 22

What is the significance of Boyle’s law to the process of respiration?

Answer 22

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

Question 23

What is the significance of Dalton’s law in the process of respiration?

Answer 23

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

Question 24

What is the significance of Henry’s law in the process of respiration?

Answer 24

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

Question 25

What happens to the process of respiration when a person is sneezing or coughing?

Answer 25

both sneezing and coughing involve a temporary cessation of respiration, known as APNEA

Question 26

What is the functional difference between the dorsal respiratory group (DRG) and ventral respiratory group (VRG) of the medulla oblongata

Answer 26

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

Question 27

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?

Answer 27

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

Question 28

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?

Answer 28

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

Question 29

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?

Answer 29

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

Question 30

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?

Answer 30

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)