-
Question 1
Correct
-
During quiet breathing the diaphragm’s role accounts for what percent of respiration?
Your Answer: 75%
Explanation:The contraction of the diaphragm accounts for approximately 75% of the air movement during normal breathing.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 2
Correct
-
After exercise, O2 debt repay may take up to:
Your Answer: 90 min
Explanation:Physical activity or exercise requires oxygen for production of ATP or energy via aerobic pathways of energy production. When the amount of oxygen that reaches muscles depletes, cells start producing energy anaerobically by partial breakdown of glucose resulting in lactic acid. Lactic acid should be removed from cells as it causes muscle fatigue. Oxygen is needed to oxidize lactic acid in to carbon dioxide and water and this need is known as oxygen debt. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise. This may take up from 60 – 90 mins.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 3
Correct
-
On a mountain the atmospheric pressure is 700 mmHg and the humidity close to zero, the partial pressure of oxygen is:
Your Answer: 147 mmHg
Explanation:Natural air includes approximately 21% of oxygen. If humidity is zero, the partial pressure of oxygen is 700 × 21% = 147 mmHg
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 4
Correct
-
Regarding bronchial innervation which of the following is correct:
Your Answer: Alpha 1 receptors increase bronchial constriction
Explanation:Stimulation of β2 receptors results in smooth muscle relaxation and bronchodilation. α1 receptors cause smooth muscle contraction in the bronchioles although minor to the β2 effects.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 5
Correct
-
During strenuous exercise the following arterial change can take place in a fit athlete:
Your Answer: No change takes place
Explanation:The changes which occur in arterial pH, PO2 and PCO2 values during exercise are usually small. Arterial PO2 often rises slightly because of hyperventilation although it may eventually fall at high work rates. During vigorous exercise, when sufficient oxygen for flux through the Krebs cycle is not available, the increased reliance on glycolysis results in increased accumulation of lactic acid, which initially leads to an increase in PaCO2 . However, this is counteracted by the stimulation of ventilation and as a result PaCO2 is decreased. This provides some respiratory compensation for further lactic acid production and prevents a decline in blood pH, which remains nearly constant during moderate exercise.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 6
Incorrect
-
The chemosensitive area in the medulla responds to:
Your Answer: Low oxygen and high hydrogen
Correct Answer: High hydrogen and high carbon dioxide
Explanation:The chemosensitive area in the medulla responds mainly to high pH levels and carbon dioxide levels. Baroreceptors in the carotid and aortic body respond mainly to oxygen and carbon dioxide partial pressure in blood.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 7
Incorrect
-
Alveolar epithelial cells:
Your Answer: Type 2 cells can secrete histamine
Correct Answer: Type 2 represent 60% of the cells
Explanation:Type I alveolar cells are squamous (giving more surface area to each cell) and cover approximately 90–95% of the alveolar surface. Type I cells are involved in the process of gas exchange between the alveoli and blood. Type II alveolar cells cover a small fraction of the alveolar surface area. Their function is of major importance in the secretion of pulmonary surfactant, which decreases the surface tension within the alveoli. They are also capable of cellular division, giving rise to more type I alveolar cells when the lung tissue is damaged. These cells are granular and roughly cuboidal. Type II alveolar cells are typically found at the blood-air barrier. Although they only comprise <5% of the alveolar surface, they are relatively numerous (60% of alveolar epithelial cells).
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 8
Incorrect
-
Which of the following statements with regards to regulation of pulmonary blood flow is correct:
Your Answer: Oxygen deficiency indirectly causes vasoconstriction
Correct Answer: Decreased blood flow to a region causes constriction of bronchi that area
Explanation:Oxygen deficiency or hypoxia has a direct effect on pulmonary vessels and results in vasoconstriction. Increased carbon dioxide levels causes pH levels to fall and results in pulmonary vasoconstriction. Decreased blood flow to a pulmonary region causes bronchoconstriction in that area to allow for flow of blood to an area where ventilation is high. Exercise increases demand of oxygen and causes increased pulmonary artery pressure.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 9
Correct
-
What is the most appropriate management of a DVT during pregnancy?
Your Answer: Heparin
Explanation:Low molecular weight heparin (LMWH) is safe in pregnancy and is therefore the first line management. Warfarin is teratogenic and must be avoided whilst the other options have no role to play.
-
This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 10
Correct
-
Carotid bodies...
Your Answer: Are located near the bifurcation of the carotid arteries bilaterally
Explanation:The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork (bifurcation) of the carotid artery (which runs along both sides of the throat).The carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature. Carotid bodies trigger an action potential through the afferent fibers of the glossopharyngeal nerve,
-
This question is part of the following fields:
- Medicine
- Respiratory
-
SESSION STATS - PERFORMANCE PER SPECIALTY
