Question

1. Which of these statements regarding the structure of the respiratory system is INCORRECT?
   1. The nose and pharynx are primarily involved in warming and humidifying air
   2. The bronchial tree becomes increasingly smaller towards the alveoli with the primary bronchi involved in filtering the air and removing foreign particles
   3. In the alveoli Type I cells are involved in surfactant production and Type II cells are involved in gas exchange
   4. The conducting airways of the lower respiratory system include the trachea and primary bronchi through to terminal bronchioles
2. The partial pressures of O2 and CO2 determine the direction of gas exchange in the body, which of these typical values is INCORRECT?
   1. P02 of 100mmHg in alveolar air
   2. PCO2 of 45mmHg in venous blood
   3. PCO2 of 40mmHg in alveolar air
   4. PO2 of 60mmHg in tissues
3. Which of these statements about muscles involved in respiration is CORRECT?
   1. Normal expiration requires contraction of the internal intercostal muscles
   2. Forced inspiration would utilise the scalenes and sternocleidomastoids in addition to the diaphragm and external intercostals
   3. Forced expiration engages the diaphragm and internal intercostals
   4. Resting inspiration primarily involves the external intercostals
4. Which of these is the main driver in initiating inspiration
   1. PO2
   2. PCO2
   3. Increase in blood H+ concentration
   4. Intrinsic activity of the pontine respiratory centre

5. What does a ventilation perfusion (V/Q) ratio of less than 0.8 suggest?
   1. That there is a blockage in blood supply to the pulmonary circuit
   2. There is an obstruction to the airways meaning that ventilation is low compared to blood flow
   3. That ventilation and blood flow are appropriately matched
   4. That air flow is being directed where perfusion is low
6. Which of these would result in respiratory alkalosis?
   1. Hyperventilation because this will result in increased removal of CO2
   2. Hyperventilation because this will result in increased intake of O2
   3. Hypoventilation because this will result in decreased removal of CO2
   4. Hypoventilation because this will result in increased intake of O2
7. Which of these would be a physiological response to a decrease in blood pH
   1. Increased ventilation rate
   2. Decreased ventilation rate
8. Which of these conditions would be considered an obstructive airways disorder?
   1. Pulmonary fibrosis
   2. Asthma
   3. Pneumothorax
   4. Infant respiratory distress syndrome
9. Glycogen is the storage form of glucose in the body, which of the following is correct regarding glycogen?
   1. Glyconeogenesis is the process of glycogen formation from glucose
   2. Gluconeogenesis is the formation of glycogen from non-carbohydrate precursors
   3. Glycogenesis is the breakdown of glycogen for energy production
   4. All statements are incorrect
10. Metabolism of triglycerides involves
    1. Beta-oxidation of fatty acids in the mitochondria
    2. Lipolysis of triglycerides releasing glycerol for use in glycolysis
    3. Lipolysis of triglycerides releasing fatty acids for use in the Krebs cycle
    4. Lipogenesis for storage of lipids for future energy requirements
    5. All of the above

11.Carbohydrate metabolism provides energy for the cell in the form of ATP. Most of the ATP is formed

1. During glycolysis by substrate level phosphorylation
2. During the TCA cycle by substrate level phosphorylation
3. During the TCA cycle through reduction of NAD
4. by the reduction of NAD during electron transport chain
5. none of the above

12. Saliva is produced by exocrine glands, which is true regarding saliva and salivatory glands?

1. Saliva production increases in response to activation of the parasympathetic nervous system
2. All salivatory glands produce saliva of the same consistency
3. Salivary amylase only becomes active in the duodenum
4. The presence of acid in saliva provides an immune defence and begins the breakdown of proteins

13.Which of the statements about the phases of gastric secretions is incorrect?

5. The cephalic phase is initiated by the CNS
6. The intestinal phase is regulated by CCK from the stomach acting on the intestines
7. Gastrin release during the gastric phase enhances gastric peristaltic motility
8. Both statements a) and b) are incorrect

Answer 1

1) c ) is incorrect... the correct answer is type 1 cell is involved in gas exchange and type 2 is involved in surfactant production..

2) d) is incorrect... the partial pressure for oxygen in tissues is about 40 mmhg.

3) d) is correct...

4) b) PCO2 is the main driving force for inspiration because as the level of co2 rises there is a build up of carbonic acid which releases hydrogen ions and reduces pH . Thus chemoreceptors present in aorta and medulla oblaganta responds to pH which is dependent upon plasma co2 level. The receptors present in aorta and carotid sinus initiates a reflex which immidiately stimulates breathing rate.