Air moving from the nose to the larynx passes by a number of structures. List as many of these structures as you can:
Nasal cavity (nares, nasal vestibule, nasal conchae), nasopharynx (with pharyngeal tonsil), oropharynx (with palatine tonsil), and laryngopharynx.
Which part of the pharynx houses the pharyngeal tonsil?
What is the structure that seals the larynx when we swallow?
Which structural features of the trachea allows it to expand and contract, yet keeping it from collapsing:
The incomplete, C-shaped cartilage rings
What features of the alveoli and their respiratory membranes suit them to their function of exchanging gases by diffusion:
The tiny alveoli together have a large surface area.
The thinness of their respiratory membrane.
List the two different circulations of the lungs and their role:
Pulmonary circulation: which delivers deoxygenated blood to the lungs for oxygenation and returns oxygenated blood to the heart.
Bronchial circulation:which provides systemic (oxygenated) blood to lung tissue.
Where is angiotensin converting enzyme found and why is this a good location for the enzyme? Name the blood pressure increasing hormone cascade to which this enzyme belongs:
In the plasma membrane of lung capillary endothelial cells. This is a good location for it because all of the blood in the body passes through the lung capillaries about once every minute.
Renin-angiotensin-aldosterone hormone cascade
What is the driving force for pulmonary ventilation:
A pressure gradient created by changes in the thoracic volume.
What causes the intrapulmonary pressure to decrease during inspiration:
The increase in thoracic cavity volume brought about by the muscles of inspiration.
What causes the partial vacuum (Negative pressure) inside the pleural cavity? What happens to a lung if air enters the pleural cavity? What is the clinical name for this condition?
The opposing forces acting on the visceral and parietal pleurae. The visceral pleurae are pulled inward by the lungs’ natural tendency to recoil and the surface tension of the alveolar fluid. The parietal pleurae are pulled outward by the elasticity of the chest wall.
-The lung on that side will collapse.
Premature infants often lack adequate surfactant, how does this affect their ability to breathe?
The lack of surfactant increases surface tension in the alveoli and causes them to collapse between breaths. (Decreases lung compliance.)
Why do slow deep breaths ventilate the alveoli more effectively than do rapid, shallow breaths:
because a smaller fraction of the tidal volume of each breath is spent moving air into and out of the dead space.
What is the difference between respiratory volumes and respiratory capacities:
Respiratory capacities are combinations of two or more respiratory volumes.
You are given a sealed container of water and air. The Pco2 and Po2 in the air are both 100 mm Hg. What are the Pco2 and Po2 in the water? which gas has more molecules in the water? Why?
In a sealed container, the air and water would be at equilibrium. Therefore, the partial pressures of CO2 and O2 (PCO2 and PO2) will be the same in the water as in the air: 100 mm Hg each. More CO2 than O2 molecules will be dissolved in the water (even though they are at the same partial pressure) because CO2 is much more soluble than O2 in water.
List three ways CO2 is transported in the blood:
-About 70% of CO2 is transported as bicarbonate ion (HCO3 −) in plasma.
-20% is transported bound to hemoglobin in the RBCs
7-10% is dissolved in plasma.
What is the relationship between CO2 and PH in the blood:
As blood CO2 increases, blood pH decreases. This is because CO2 combines with water to form carbonic acid.
Which brain stem respiratory area is thought to generate the respiratory rhythm:
The ventral respiratory group of the medulla (VRG)
Which chemical factor in blood usually provides the most powerful stimulus to breathe? Which chemoreceptors are most important to this response:
What long term adjustments does the body make when living at high altitudes:
Long-term adjustments to altitude include an increase in erythropoiesis, resulting in a higher hematocrit; an increase in BPG, which decreases Hb affinity for oxygen; and an increase in minute respiratory volume.
What distinguishes the obstruction in asthma from that in chronic bronchitis?
The obstruction in asthma is reversible, and acute exacerbations are typically followed by symptom-free periods. In contrast, the obstruction in chronic bronchitis is generally not reversible.
During inspiration, air moves into the lungs because:
the gas pressure in the lungs becomes lower than the outside pressure as the diaphragm contracts.
Alveolar ventilation rate is
the movement of air into and out of the alveoli during a particular time.
AVR = breaths per minute × (TV – dead space)
Hemoglobin has a tendency to release oxygen where
pH is more acidic
In the alveoli, the partial pressure of oxygen is
approximately 104 millimeters of mercury
Most of the carbon dioxide transported by the blood is
converted to bicarbonate ions and transported in plasma
The movement of air into and out of the lungs is called
Which tissue lines the trachea?
pseudostratified columnar epithelium
Of the respiratory measurements listed, which one normally has the greatest value?
Which respiratory structure has the smallest diameter?
Involuntary hyperventilation during an anxiety attack can cause a person to become faint because of:
lowered CO2 levels in the blood and consequent constriction of cerebral blood vessels
Which of the following gases has NO effect in the blood until hyperbaric conditions occur, such as in scuba diving, and can form bubbles in blood when an individual surfaces too quickly?
Which of the following terms describes the increase in depth and force of breathing that occurs during vigorous exercise?
Approximately 20% of carbon dioxide is transported in the blood as:
Which of the following control(s) the respiratory rate?
Which of the following is NOT a function of the conducting zone of the respiratory tract?
Gas Exchange, walls are to thick.
What enzyme, which is ideally located in the lung capillary membrane of the pulmonary circuit, acts on material in the blood, thereby activating an important blood pressure hormone?
angiotensin converting enzyme
What type of pressure keeps the air spaces in the lungs open?
Airway resistance is insignificant in relationship to gas flow because:
the airways branch extensively as they get smaller, resulting in a huge total cross-sectional area
The transpulmonary pressure is the difference between the __________ and the __________ pressure.
Which of the following conditions would NOT decrease the total respiratory compliance?
increase in lung compliance
Which substance, produced by type II alveolar cells, decreases alveolar surface tension?
Which of the following nonrespiratory movements is caused by irritation of the nasal cavity?
The dorsal respiratory group __________.
is located near the root of cranial nerve IX
Which of the following would NOT be found in a “blue bloater”?