Module 2: Respiratory Sciences

Question 1

What is the sensory nerve supply of the following:

1. Pharyngotympanic tube?
2. Nasopharynx?
3. Oropharynx?
4. Laryngopharynx?

Answer 1

1. Pharyngotympanic tube: CN 9
2. Nasopharynx: CN 9 and 5b
3. Oropharynx: CN 9
4. Laryngopharynx: CN 9 and 10

Question 2

1. How many pharyngeal constrictor muscles are there?
2. What is their motor supply?
3. What are the names of the 5 longitudinal internal muscles of the pharynx?
4. The motor supply for all of these is CN 10 except for which two?
5. What is the motor supply for these two?

Answer 2

1. 3 muscles (superior, middle and inferior)
2. Motor supply = CN 10
3. Levator veli palatini, tensor veli palatini, salpingopharyngeus, stylopharyngeus and palatopharyngeus
4. Tensor veli palatini and stylopharyngeus
5. Tensor veli palatini = CN 5c
   Stylopharyngeus = CN 9

Question 3

1. In which direction do you pull the pinna in adults?
2. In which direction do you pull the pinna in children?
3. What are the names of the ossicles from lateral to medial?

Answer 3

1. Adults: postero-superiorly
2. Children: postero-inferiorly
3. Malleus, incus and stapes

Question 4

1. What is the name of the middle ear muscle that inserts into the neck of the malleus and what is its nerve supply?
2. What is the name of the middle ear muscle that inserts into the neck of the stapes and what is its nerve supply?

Answer 4

1. Tensor tympani = CN 5c

2. Stapedius = CN 7

Question 5

1. What are the other two names for the pharyngotympanic tube?
2. What are the two types of otitis media? Give the common name for one of them…

Answer 5

1. Eustachian and auditory

2. Acute suppurative otitis media and secretory otitis media (glue ear)

Question 6

1. What is antigenic shift and what percentage of amino acid sequence change occurs?
2. What is antigenic drift and what percentage of amino acid sequence change occurs?

Answer 6

1. Random spontaneous mutation in viral genes encoding HA and NA = 1-2% change
   [HA=haemagglutinin
   NA= neuraminidase]
2. Genetic re assortment between human and non-human viruses leading to new subtype = >20% change

Question 7

1. During which weeks does a septum grow to divide the tracheal bud from the oesophagus?
2. What week does the respiratory epithelium begin to develop?
3. What is the nerve supply of the parietal pleura of the lungs?
4. Which nerves run anterior to the hilum?
5. Which nerves run posterior to the hilum?

Answer 7

1. Septum: weeks 4-5
2. Epithelium: week 26+
3. Phrenic nerve (C3, 4, 5)
4. Phrenic nerves
5. Vagus nerves

Question 8

1. Name 3 pre-linguistic types of communication…

Answer 8

1. Crying, smiling and gestures

Question 9

1. Why are the 2 zones on the pathway of gas exchange?

2. What is dead space and what are the two types? Which is morphological and which is functional?

Answer 9

1. Conducting zone and respiratory zone
2. Dead space = volume of air not participating in gas exchange
   Anatomical dead space: morphological
   Physiological dead space: functional

Question 10

Out of oxygen and carbon dioxide…

1. Which has small partial pressure gradients?
2. Which is 20x more soluble?

Answer 10

1. Carbon dioxide

2. Carbon dioxide

Question 11

What 3 factors explained in Fick’s law, influence the rate of a gas?

Answer 11

1. Rate proportional to surface area of tissue
2. Rate is inversely proportional to tissue thickness
3. Rate depends on diffusion constant and on gas physical characteristics

Question 12

1. In hypercapnia, what do bronchioles do and why?

2. In hyopoxia, what do pulmonary arterioles do and why?

Answer 12

1. Bronchioles dilate to improve air flow

2. Pulmonary arterioles constrict to reduce flow and redirect blood to better perfumed areas

Question 13

1. What percentage of blood is physically dissolved?
2. What percentage of blood is bound to haemoglobin in red blood cells?
3. What two things does haemoglobin contain?
4. What is the difference between adult and fetal haemoglobin?

Answer 13

1. = 1.5%
2. = 98.5%
3. Haem = Fe2+ containing molecule
   globin = 4 polypeptide chains
4. Adult Hb: 2 alpha and 2 beta chains
   Fetal: 2 alpha and 2 gamma chains

Question 14

1. Oxygen binds to iron in what state?

2. Give 3 properties of the oxygen-Hb dissociation curve…

Answer 14

1. Ferrous state (Fe2+)

2. Sigmoid curve, allosteric shape change and co-operative binding

Question 15

Define the following:

1. O2 pressure
2. O2 capacity
3. O2 content
4. O2 saturation

Answer 15

1. O2 pressure: amount of oxygen dissolved in plasma
2. O2 capacity: amount of oxygen bound to Hb
3. O2 content: amount of oxygen dissolved + amount of oxygen bound
4. O2 saturation: % of available binding sites bound to oxygen

Question 16

1. What 4 factors reduce oxygen-Hb affinity and help unload oxygen to tissues?
2. What shift does this cause in the oxygen-Hb dissociation curve?

Answer 16

1. Acidic pH, increased PaCO2, raised body temperature and 2,3 biphosphoglycerate
2. Right hand shift

Question 17

1. What 4 factors increase oxygen-Hb affinity and prevent unloading of oxygen to tissues?
2. What shift does this cause in the oxygen-Hb dissociation curve?

Answer 17

1. Alkaline pH, reduced PaCO2, lowered body temperature and fetal haemoglobin
2. Left hand shift

Question 18

1. The lateral wall on the nasal cavities have 3 what? And what is the area under this called?
2. What is the sensory supply to the nasal cavity? (Name 3)
3. What are the names of the 4 sinuses around your nose?

Answer 18

1. 3 conchae with 3 meatus underneath
2. CN 5a, CN 5b and CN 1
3. Frontal air sinus, sphenoid sinus, ethmoid sinus and maxillary air sinus

Question 19

1. What is SaO2?
2. What is a normal SaO2 reading?
3. Below what value is abnormal and action would be required?

Answer 19

1. SaO2: % of Hb saturated with oxygen
2. Normal = 98-100%
3. Abnormal =

Question 20

1. Apart from Hb, what also shuttles oxygen?
2. From where to where?
3. Does co-operative binding happen?
4. Does it have a higher or lower affinity for O2 compared with Hb?

Answer 20

1. Myoglobin (Mb)
2. Cell membrane to mitochondria
3. No co-operative binding
4. Higher affinity for O2 than Hb

Question 21

1. What does haem do?
2. What 3 nutritional problems could stop us from making haem?
3. What mutations cause defects in Haem synthesis?

Answer 21

1. Catalyse electron transfer reactions, especially with diatomic gases
2. General nutritional deficit, iron poor diet and vitamin B6 deficiency
3. Porphyrias

Question 22

What are the 3 methods of CO2 carriage in the blood and how much percent is each one?

Answer 22

1. In solution in plasma = 9%
2. Carbamino Hb = 13%
3. Bicarbonate ion = 78%

Question 23

1. What shape is dissociation of CO2 from blood?
2. What has a major effect on the curve?
3. What has a greater affinity for CO2: deoxyHb or oxyHb?
4. What blood transports CO2 more readily: venous or arterial?

Answer 23

1. Linear
2. Saturation of Hb with O2
3. DeoxyHb
4. Venous

Question 24

1. What is the normal pH for systemic arterial blood?
2. What is acidosis?
3. What is alkalosis?

Answer 24

1. pH 7.4
2. pH below 7.35
3. pH above 7.45

Question 25

1. What produces free H+? | 2. Give 3 methods of this?

Answer 25

1. Metabolic production of acid | 2. Carbonic acid, non-volatile acid produced from nutrient breakdown and organic acids from intermediate metabolism

Question 26

What 3 lines of defence are there against pH disorders? How fast do they work?

Answer 26

1. Chemical buffers (fractions of a sec) 2. Adjusting ventilation to change PaCO2 (mins) 3. Adjusting renal acid or alkalis excretion (hours to days)

Question 27

What are the 3 main extracellular buffer systems?

Answer 27

1. Protein buffer system 2. Phosphate buffer system 3. Carbonic acid-bicarbonate buffer system

Question 28

1. What are the 3 parts of the bicarbonate buffer system? 2. What enzyme catalyses the first part? 3. What regulates the CO2? 4. What regulates the HCO3- and H+?

Answer 28

1. CO2 + H2O --->H2CO3 ---> H+ + HCO3- 2. Carbonic anhydrase 3. Lungs 4. Kidneys

Question 29

1. What are the two types of causes of acid base disturbances and what do they point towards as the main problem? 2. What is the cause of respiratory acidosis? 3. What is the cause of respiratory alkalosis?

Answer 29

1. Respiratory cause: CO2 main cause Non-respiratory (metabolic) cause: HCO3- main cause 2. Elevation of PCO2 of blood (lack of removal) 3. Arterial blood PCO2 too low (increased removal)

Question 30

1. What is type 1 respiratory failure? | 2. What is type 2 respiratory failure?

Answer 30

1. Hypoxaemia | 2. Hypoxaemia and hypercapnia

Question 31

1. What is pneumonia? | 2. What two things is pneumonia characterised by?

Answer 31

1. Inflammatory reaction of alveoli and interstitium 2. Characterised by: - inflammatory exudate in alveolar space that consolidates - inflammation of alveolar septa

Question 32

1. What are the 3 types of bronchodilators? | 2. What are the 2 types of anti-inflammatories?

Answer 32

1. Beta agonists, muscarinic receptor antagonists and methylxanthines 2. Corticosteroids and leukotriene receptor antagonists

Question 33

What is meant by obstructive disease? (Give 4 points)

Answer 33

- limitation of airflow due to obstruction - increased airway resistance - airway narrowing - loss of elasticity or increased secretions

Question 34

What is meant by restrictive disease? (Give 3 points)

Answer 34

- restrict normal respiratory lung movement - reduced expansion of lung tissue - decreased total lung capacity

Question 35

What is: 1. COPD? 2. Chronic bronchitis? 3. Emphysema? 4. Asthma? 5. Bronchiectasis?

Answer 35

1. Chronic bronchitis and emphysema 2. Mucus hyper-secretion in airways 3. Dilation of respiratory bronchioles and alveoli and destruction of elastic tissue 4. Chronic inflammation of the airways making them hyper responsive and narrow 5. Permanent dilation of main bronchi and bronchioles

Question 36

1. What is compliance? 2. What is adherence? 3. What is concordance? 4. What are 5 big barriers to adherence?

Answer 36

1. Compliance: following a practitioners advice or instructions 2. Adherence: behaviour that optimises therapeutic efficacy 3. Concordance: shared and negotiated agreement between patient and practitioner 4. Professional, practical, information, lifestyle choices and beliefs about medicine

Question 37

What are 5 aspects that define neoplasia?

Answer 37

1. New growth 2. Non lethal genetic alteration 3. Growth is not regulated 4. Growth maintained in the absence/ removal of the stimulus 5. Can be benign or malignant

Question 38

What are the 4 classes of genes that tend to be affected by carcinogenesis?

Answer 38

1. Growth promoting proto-oncogenes 2. Growth inhibiting tumour suppressor genes 3. Genes regulating apoptosis 4. Genes involved in DNA repair

Question 39

What are the 4 ways to know if a tumour is benign or malignant?

Answer 39

1. Degree of differentiation/anaplasia of parenchymal tissue 2. Rate of growth 3. Local invasion 4. Metastasis

Question 40

Benign vs malignant: what would be the difference between the two in the following aspects... 1. Differentiation/anaplasia 2. Rate of growth 3. Local invasion 4. Metastasis

Answer 40

1. Benign: well differentiated morphologically and functionally Malignant: well differentiated to undifferentiated 2. Benign: generally slowly (can grow quickly under hormonal influence) Malignant: generally quickly (less differentiated = more quickly) 3. Benign: rarely invasive Malignant: infiltrate surrounding tissue and invade adjacent tissues 4. Benign: no metastasis - they compress adjacent tissues/uncontrolled hormone release Malignant: locally invade, then travel in blood/lymph, to produce secondary tumour

Question 41

1. What are the 3 parts of tumour staging?

Answer 41

1. Tumour, nodes and metastases

Question 42

1. What causes tuberculosis? | 2. What 4 ways can you describe it?

Answer 42

1. Mycobacterium tuberculosis | 2. Obligate aerobe,rod shaped bacillus, acid fast and non-spore forming