Respiratory Flashcards
What is an average tidal volume?
500mL
What is a normal vital capacity?
4.8L
What is the residual volume of the lungs?
1.2L
What is vital capacity?
Total volume of air possible to expire?
Define residual volume.
Volume of the lungs with no air
How do you work out total lung volume?
Vital capacity + residual volume
How do you calculate minute ventilation?
Tidal volume x respiratory rate
How do you calculate alveolar ventilation?
(tidal volume - dead space) x respiratory rate
What is the normal volume of anatomic dead space in the lungs?
150mL
What is FVC?
Forced vital capacity, the maximum volume exhaled
What is FEV1?
Forced expiratory volume within 1 second, should be 80% of FVC
What findings in lung function tests are indicative of obstructive lung disease?
Reduced FEV1 due to increased resistance, less than 80% of FVC
What findings in lung function tests are indicative of restrictive lung disease?
FEV1 and FVC reduced but with FEV1 over 80% of FVC
Vital capacity reduced due to lack of elasticity
What is lung compliance?
The ease with which lungs and thorax expand
What results in high compliance?
Old age, emphysema
Small increase in TP, large increase in volume due to loss of elastic recoil
What results in low compliance?
Oedema, fibrosis, pneumonia
Large increase in TP, small increase in volume due to increased collagen expression and inflammation
What is newborn respiratory distress syndrome?
Occurs in premature babies, type II cuboid cells are underdeveloped reducing surfactant secretion, causing alveolar collapse on expiration
What conditions can cause alveolar collapse on expiration?
Arthritis
Ankylosing spondylitis
Due to reduced spinal cord/rib articulation
What is emphysema?
Degeneration of alveolar, bronchiole walls and capillaries due to proteolytic attack by leukocyte proteases, increasing alveolar dead space.
List the 4 main conducting airways.
Trachea
Bronchi
Bronchioles
Terminal bronchioles
List the 3 main respiratory airways.
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
What is the opening of the larynx?
Glottis, covered by the epiglottis
What are the roles of the conducting airways?
Low resistance pathway for air flow
Warms and moistens air to increase efficiency
Defence against infection
What are the features of the respiratory tract that defend against infection?
Macrophages
Cilia
Mucus secretion and escalator
Movement of chloride ions out of cells