Respiratory Physiology

Question 1

Describe the mechanisms of the breathing process.

Answer 1

To inhale – diaphragm and external intercostals are contracted ➡️ pulling down diaphragm and expanding the ribs ➡️ increases the volume of the chest cavity ➡️ decreases the pulmonary pressure ➡️ higher pressure gradient atmospheric air outside body rushes in ➡️ lung elasticity recoils ➡️ decreasing the volume and increasing pulmonary pressure ➡️ movement of air out of the lungs

Question 2

Are muscles used during expiration?

Answer 2

Only during forced expiration when there is a contraction of the abdominal muscles

Question 3

When are accessory muscles used during breathing? Which muscles

Answer 3

During pulmonary disease or during exercise. The scalenes, sternocleidomastoid, and pectorals are used to further increase the volume expansion of the thorax.

Question 4

What is lung compliance?

Answer 4

The ease with which the lungs can be expanded by muscle contraction of the thorax.

Question 5

What factors can decreased lung compliance?

Answer 5

Fibrosis, thorax i flexibility, blocked bronchi, increased alveolar surface tension, lack of surfactant, atelectasis

Question 6

What is lung elasticity?

Answer 6

The ease with which the lungs can contract to their normal resting size (exhalation) after expanding during inhalation

Question 7

Name each breath sound and where it is heard

Answer 7

Tracheal in the notch above the manubrium.
Bronchial over the throat.
Broncho-vesicular in the medial lung areas. Vesicular heard in the lung periphery.

Question 8

Name and describe the four adventitious breath sounds

Answer 8

Rails/crackles: popping sounds in the airway more common during inspiration. Implies accumulation of secretions or edema in the airway.
Rhonchi/wheezing: high-pitched tones heard during inspiration, expiration or both. Can imply a collapsed airway, a foreign body/object or extensive secretions (asthma)
Stridor: lodged foreign object, choking
Plural friction rub: Caused by rubbing of inflamed pleural surfaces, pleurisy

Question 9

Describe tactile fremitus and what it indicates

Answer 9

With medial surface of hand on patient have the patient say “99” – Tactile fremitus may be decreased or absent when vibrations from the larynx to the chest surface are impeded by chronic obstructive pulmonary disease, obstruction, pleural effusion, or pneumothorax. It is increased in pneumonia.

Question 10

Describe three things that can be said when assessing voice sounds with a stethoscope. What do they indicate?

Answer 10

Broncophony: Bluemoon – increased vocal transmission can indicate consolidation due to pneumonia
Egophony: patient says “E”- if it sounds like “A” then it could be consolidation due to pneumonia
Pectoriloquy: patient whispers “99” – Increased transmission indicates consolidation

Question 10

What is the purpose of mediate percussion?

Answer 10

To assess the density of underlying lung tissue or organs and assessing the amount of air inside the thorax

Question 11

Explain normal tones in mediate percussion

Answer 11

Resonant: over air filled structures — lungs
Dull: over solid organs — liver
Flat: over muscle mass (high pitch and short duration)
Tympanic: heard over hollow structures — stomach (high pitch, medium duration)

Question 12

What are abnormal tones in mediate percussion and what do they mean?

Answer 12

Tympanic — over chest where lungs (resonant) should be is possible pneumothorax and can be life threatening
Hyperresonant — increases as thoracic air increases indicative of emphysema
Dull or Hyporesonant — as thoracic air decreases can be due to pneumonic consolidation, atelectasis, pleural effusion

Question 13

What is pleural effusion and what causes it?

Answer 13

Excess fluid in the plural space. Caused by:
•Congestive heart failure
•Pneumonia
•Liver disease (cirrhosis)
•End-stage renal disease
•Nephrotic syndrome
•Cancer
•Pulmonary embolism
•Lupus and other autoimmune conditions

Question 14

What does tracheal deviation indicate?

Answer 14

Deviated towards diseased side:
• Atelectasis
• Agenesis of lung
• Pneumonectomy
• Pleural fibrosis
Deviated away from diseased side:
• Pneumothorax
• Pleural effusion
• Large mass

Question 15

Describe how you assess diaphragmatic excursion. What is normal?

Answer 15

Take and hold a deep breath. Using mediate percussion find the lowest point where a resonant tone is heard. This is the lowest level of the diaphragm. Mark this level.
Now exhale and hold the exhalation. Again using mediate percussion find the lowest area of resonance this is now the highest point of the diaphragm. Mark it and take a measurement between the two marks.
Normal is 3 to 5 cm

Question 16

What is normal chest wall excursion in the young adult?

Answer 16

3.5 inches (8.5 cm)

Question 17

Where are measurements taken when using a tape measure for chest wall excursion?

Answer 17

Fourth costal cartilage, xiphoid process, ninth costal cartilage

Question 18

Explain FEV1/FVC

Answer 18

This is the percentage of vital capacity that can be exhaled in the first second forceful exhalation. It should be >60%

Question 19

Which lung volumes are increased and decreased and obstructive lung disorders?

Answer 19

Increased: residual volume and functional residual capacity, RV/TLC
Decreased: vital capacity, inspiratory reserve volume, expiratory reserve volume, FEV1/FVC

Question 20

Which lung volumes are affected and restrictive lung disorders?

Answer 20

Decreased vital capacity, residual volume, functional residual capacity, total lung capacity, and tidal volume

Question 21

What are obstructive lung disorders?

Answer 21

Characterized by airway obstruction, reduced airway flow rates, particularly on forced exhalation.
Asthma, emphysema, chronic bronchitis, bronchiectasis, cystic fibrosis

Question 22

What are restrictive lung disorders?

Answer 22

Characterized by a reduction in vital capacity may be pulmonary or extrapulmonary.
Atelectasis, pneumothorax, pneumonias, adult respiratory distress syndrome and infant respiratory distress syndrome, pulmonary fibrosis, lung carcinomas, skeletal issues, neuromuscular issues, abdominal ascites

Question 23

What are the two types of emphysema

Answer 23

Panacinar- effects the alveoli throughout the lungs

Centrilobar - effects respiratory bronchioles in the upper lobes mostly

Question 24

Describe some major points about emphysema

Answer 24

They are called pink puffers because they are purse lip breathers they are very thin from muscle wasting due to working so hard to breathe. They have increased lung compliance and decreased elastic recoil. Generally short of breath with an often dry cough they have reduced breath sounds. FRC and RV are increased while FEV1 and VC are decreased. Equal deficit of V&Q.

Question 25

Describe end stage emphysema

Answer 25

Hypoxemia, edema and fluid overload from right-sided heart failure. Can progress to left-sided heart failure later. Pulmonary embolism. Multi organ system ischemia: brain, kidney, heart and lungs

Question 26

Describe the general picture of chronic bronchitis pt.

Answer 26

Blue bloater- often overweight and cyanotic. Excessive mucus mucus production, frequent respiratory infections, cough with chronic sputum, cyanosis due to hypoxemia, fluid retention leading to edema. Pulmonary hypertension leading to right ventricular failure, compliance often normal, decreased FEV1

Question 27

Describe general asthma signs and symptoms

Answer 27

Recurrent bronchial inflammation and secretions generally due to reactions to allergens. Periodic exacerbations, with wheezing and bronchospasms. Can’t have hyperinflated lungs: air trapping, difficulty exhaling, reduced FEV1

Question 28

Describe bronchiectasis

Answer 28

Dilation of the bronchial walls, destroyed integrity of the bronchial wall. Usually results of recurrent infection; scar tissue weakens the walls and they’re stretched by coughing. They retain secretions which become infected and then infect other lung regions. Generally treated with bronchial hygiene.

Question 29

Name the three types of bronchiectasis

Answer 29

Cylindrical, varicose, cystic or saccular

Question 30

Describe atelectasis

Answer 30

Partial collapse of lung parenchyma, alveoli. Two types microatelectasis and obstructive.

Question 31

Describe micro-atelectasis

Answer 31

Alveolar collapse related to surface tension changes (respiratory distress) or left ventricular failure. Occurs quickly most often due to bed rest. Maybe diffuse or localized. Most commonly caused by hypoventilation, decreased lung compliance.

Question 32

Describe obstructive atelectasis

Answer 32

Occurs when a bronchus is totally occluded can be by: carcinoma, mucous plug, inhalation of foreign object. Distal to the obstruction extra air is reabsorbed and then the airways collapse. Usually associated with a tracheal shift.

Question 33

Describe pneumonias in general, how are they classified

Answer 33

Classified according to causative agent: bacterial/viral/fungal, chemical, aspiration. Can have lobar or bronchial presentation

Question 34

Describe bronchial pneumonia

Answer 34

Usually caused by staphylococcal or streptococcal organism. Little consolidation. Inflammation of airways with secretions and increased mucus production. Fever and shortness of breath with productive purulent sputum with coughing.

Question 35

Describe lobar pneumonia

Answer 35

Usually caused by pneumococcus, inflammation of the distal airways. Consolidation inflammatory exudate fills the alveoli and the plural membranes are often involved. Cough is initially dry and later productive with golden viscous blood-flecked sputum.