Respiratory Physiology Flashcards
Describe the mechanisms of the breathing process.
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
Are muscles used during expiration?
Only during forced expiration when there is a contraction of the abdominal muscles
When are accessory muscles used during breathing? Which muscles
During pulmonary disease or during exercise. The scalenes, sternocleidomastoid, and pectorals are used to further increase the volume expansion of the thorax.
What is lung compliance?
The ease with which the lungs can be expanded by muscle contraction of the thorax.
What factors can decreased lung compliance?
Fibrosis, thorax i flexibility, blocked bronchi, increased alveolar surface tension, lack of surfactant, atelectasis
What is lung elasticity?
The ease with which the lungs can contract to their normal resting size (exhalation) after expanding during inhalation
Name each breath sound and where it is heard
Tracheal in the notch above the manubrium.
Bronchial over the throat.
Broncho-vesicular in the medial lung areas. Vesicular heard in the lung periphery.
Name and describe the four adventitious breath sounds
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
Describe tactile fremitus and what it indicates
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.
Describe three things that can be said when assessing voice sounds with a stethoscope. What do they indicate?
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
What is the purpose of mediate percussion?
To assess the density of underlying lung tissue or organs and assessing the amount of air inside the thorax
Explain normal tones in mediate percussion
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)
What are abnormal tones in mediate percussion and what do they mean?
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
What is pleural effusion and what causes it?
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
What does tracheal deviation indicate?
Deviated towards diseased side: • Atelectasis • Agenesis of lung • Pneumonectomy • Pleural fibrosis Deviated away from diseased side: • Pneumothorax • Pleural effusion • Large mass
Describe how you assess diaphragmatic excursion. What is normal?
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
What is normal chest wall excursion in the young adult?
3.5 inches (8.5 cm)
Where are measurements taken when using a tape measure for chest wall excursion?
Fourth costal cartilage, xiphoid process, ninth costal cartilage
Explain FEV1/FVC
This is the percentage of vital capacity that can be exhaled in the first second forceful exhalation. It should be >60%
Which lung volumes are increased and decreased and obstructive lung disorders?
Increased: residual volume and functional residual capacity, RV/TLC
Decreased: vital capacity, inspiratory reserve volume, expiratory reserve volume, FEV1/FVC
Which lung volumes are affected and restrictive lung disorders?
Decreased vital capacity, residual volume, functional residual capacity, total lung capacity, and tidal volume
What are obstructive lung disorders?
Characterized by airway obstruction, reduced airway flow rates, particularly on forced exhalation.
Asthma, emphysema, chronic bronchitis, bronchiectasis, cystic fibrosis
What are restrictive lung disorders?
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
What are the two types of emphysema
Panacinar- effects the alveoli throughout the lungs
Centrilobar - effects respiratory bronchioles in the upper lobes mostly
