Respiratory knowledge tutor key points

Question 1

Thoracic duct perforates the diaphragm:

Answer 1

T12

• aorta
• thoracic duct
• coeliac trunk leaves the aorta

T8
- inferior vena cava

Question 2

What type of blood gas abnormality does altitude most commonly cause?

Answer 2

respiratory alkalosis

Question 3

Fibrosis predominately affecting the upper zones

Answer 3

CHARTS

Coal worker pneumoconiosus 
Histocytosis 
Ankylosing Spondylitis 
Radiation 
Tuberculosis 
Silicosis / sarcoidosis

Question 4

fibrosis predominantly affecting the lower zone

Answer 4

• asbestosis
• connective tissue disorders, SLE
• idiopathic pulmonary fibrosis

Question 5

Total lung capacity:

Answer 5

Equals vital capacity + residual volume

Question 6

In a patient with:

• pneumonia
• dry cough
• atypical chest signs
• autoimmune haemolytic anaemia
• erythema multiforme

is most associated with which organism?

Answer 6

mycoplasma pneumoniae

Question 7

An 80-year-old man who used to work in ship building presents with progressive shortness-of-breath. A chest x-ray shows multiple pleural plaques and bilateral lower zone interstitial shadowing

Answer 7

asbestosis

- often affects lower zone

Question 8

Summarise the key pathophysiology in asthma

Answer 8

• chronic inflammation
• many eosinophils release granules (histamine, leukotrienes etc.)

combined with environmental factors:

• —-> 1. smooth muscle spasms
• —-> 2. increased mucus secretion

-TH2 cells —> cytokines —> IL-5, attracts and activates more eosinophils
OR
- neutrophils —> IL8 more severe form

Question 9

Irreversible changes seen in asthma

Answer 9

1. Oedema
2. Scarring
3. Fibrosis

• —-> thickened basement membrane
• ———-> reduces airway diameter

Question 10

COPD involves what two conditions

Answer 10

1. Chronic bronchitis (productive cough)

2. Emphysema ( enlargement of airspaces)

Question 11

Summarise type 1 respiratory failure

Answer 11

1. Fluid in lungs
   - —> water (pulmonary oedema)
   - —> pus (pneumonia)
   - —> blood (haemorrhage)
2. Oxygen diffusion impairment
3. Hypoxemia as oxygen can’t diffuse
4. Occurs with diseases and damage to lung tissues

Question 12

Summarise type 2 respiratory failure

Answer 12

1. Obstruction?
2. asthma, COPD
3. anything depressing respiratory drive
4. neuromuscular conditions such as Guillain Barre or myasthenia gravis.
5. CO2 collects leading to hypercapnia

Question 13

Two classic clinical signs of idiopathic pulmonary fibrosis?

Answer 13

1. dry cough

2. SOB

Question 14

What occurs in the pathophysiology of idiopathic pulmonary fibrosis?

Early inflammatory stage

Answer 14

1. repetitive exposure to unknown antigen leads to repetitive cycles of alveolitis
   - —-> type 1 pneuomocyte damage
2. m.phages —cytokine—> IL-8, TNF
3. chemotaxis of inflam cells : neutrophils, eosinophils and fibroblasts

LEADS TO

• ——–> 1. Diffuse interstitial pulmonary fibrosis
• ——–> 2. DILATION of prox. small airways

ALVEOLITIS

• type 1 pneumocyte damage
• capillary damage, leakage, leads to interstitial and alveolar oedema —> Hyaline membrane formation

Question 15

pathophysiology of idiopathic pulmonary fibrosis?

Late inflammatory stage

Answer 15

1. increased permeability of capillary and alveoli
2. inflammatory cells reach alveoli
3. fibrosis

Question 16

Summarise diagnosis of Idiopathic pulmonary fibrosis?

Answer 16

1. Serum Acute phase reactant (lung inflammation)
   a) Anti-nuclear antibodies (ANA)
   b) rheumatoid factor (RF)
2. increased m.phage and neutrophils
3. restrictive thus lung volumes decreased, low FVC but FEV1/FVC ratio should be normal or slightly high
4. Aa gradient increased
5. DLCO decreased

Question 17

ABG of a patient with idiopathic pulmonary fibrosis may show?

Answer 17

Respiratory alkalosis due to dysponea

Question 18

What might be characteristically seen on CXR of patient with idiopathic pulmonary fibrosis?

Answer 18

Early
- bilateral, diffuse infiltrates

Late
- honeycomb lung, cysts surrounded by fibrosis

Question 19

Define sarcoidosis?

Answer 19

1. chronic immune related
2. multisystem granulomatous disease
3. non-infectious, non ceasating granulomas

Question 20

Summarise the pathophysiology of sarcoidosis?

Answer 20

• unknown antigen
• CD4+ T-helper cells —–release—–> cytokines
• non infectious, noncaseating granuloma, epitheloid histocytes (m.phages)
• m.phages in granuloma release 1-a-hydroxylase enzyme
• converts vitamin D to active form
• hypervitaminosis D —–> Hypercalcaemia —-> calcium kidney stones, Very severe pain
• increased Ca2+ absorption from small intestine and reabsorption from DCT via principle cells

Question 21

which intrinsic muscles of larynx open up the airway by separating the vocal folds?

Answer 21

posterior cricoarytenoid muscles

Question 22

All intrinsic muscles of the larynx are supplied by which nerve?

who’s the only exception?

Answer 22

recurrent laryngeal nerve of the vagus

only exception are cricothyroid which are supplied by external branch of superior laryngeal nerve.

Question 23

true vocal folds are lined by what mucosa?

Answer 23

• stratified squamous mucosa , protective as vocal folds exposed to wear and tear.
• not the typical resp epithelium that lines the rest of the tract.
• epiglottis also lined by protective stratified squamous epithelium. largely composed of elastic cartilage.

Question 24

in embryology the thyroid gland descends from the …

Answer 24

foramen caecum

Question 25

describe the blood supply of the thyroid gland

Answer 25

- superior thyroid artery which is a branch of the external thyroid artery. - inferior thyroid artery which is a branch of the thyrocervial trunk of first part of subclavian artery

Question 26

venous drainage of thyroid

Answer 26

- superior and middle thyroid veins - to internal jugular veins - via inferior thyroid veins - to brachiocephalic vein

Question 27

what muscle causes tongue to protrude?

Answer 27

- genioglossus muscle - tongue has squamous epithelium - thus tumours arising from tongue are typically squamus cell carcinomas

Question 28

all muscles of tongue are supplied by which nerve? what is the only exception?

Answer 28

- muscle of the tongue are supplied by hypoglossal nerve | - exception of palatoglossus muscle which is supplied by pharyngeal plexus of nerves

Question 29

what nerve may be injured during submandibular gland procedures?

Answer 29

hypoglossal nerve

Question 30

parathyroid gland are all usually supplied by which artery?

Answer 30

inferior thyroid artery

Question 31

calcitonin secreted from

Answer 31

parafollicular cells of thyroid glands

Question 32

why are salivary stones more commonly encountered in submandibular gland and less commonly found in parotid gland?

Answer 32

- parotid mainly serous gland | - few scattered mucinous acini

Question 33

pes anserinus

Answer 33

five terminal branches of facial nerve

Question 34

four muscles of mastication are...

Answer 34

1. Temporalis 2. Masseter 3. Medial pterygoid 4. lateral pterygoid

Question 35

buccinator muscle innervated by

Answer 35

facial nerve not a muscle of mastication

Question 36

muscles of mastication are innervated by the ...

Answer 36

mandibular division of the trigeminal nerve

Question 37

describe the dual blood supply of the lungs?

Answer 37

- via pulmonary artery and the bronchial arteries - thus obstruction of a small pulmonary arteriole by pulmonary embolus will have no minor effect if patient has intact bronchial circulation

Question 38

describe the differences in innervation of pleura covering the lungs?

Answer 38

- visceral is poorly innervated, autonomic - parietal, rich innervation from intercostal nerves and phrenic nerve. - so in lung disease when disease crosses visceral to parietal pleura, pain becomes an important factor