Ventilation and compliance Flashcards
what is pulmonary surfactant?
- a surface active lipoprotein complex
what is pulmonary surfactant formed by?
type 2 alveolar cells
what is pulmonary ventilation?
it is the process of air flowing into the lungs during inspiration and out of the lungs during expiration
inspiration
inhalation
expiration
exhalation
what is alveolar ventilation?
the volume of gas expired from alveoli to the outside of the body per minute
what is the exchange of gas between the alveoli and the external environment called?
alveolar ventilation
what is alveolar ventilation?
it is the process by which oxygen is brought into the lungs from the atmosphere and by which the carbon dioxide carried into the lungs in the mixed venous blood is expelled from the body
what is compliance?
arterial compliance is the change in arterial blood volume due to a given change in arterial blood pressure
what is C?
compliance = the change in volume divided by change in pressure
what is an important cardiovascular risk factor?
arterial compliance
what is an index of the elasticity of large arteries such as the thoracic aorta?
arterial compliance
what is compliance of arteries?
vascular compliance
what is vascular compliance?
the ability of a blood vessel wall to expand and contract passively with changes in pressure is an important function of large arteries and veins
what is an important measurement in respiratory physiology?
lung compliance
what is associated with a decrease in pulmonary compliance?
fibrosis
what is associated with an increase in pulmonary compliance due to the loss of alveolar and elastic tissue?
emphysema/COPD
what are pulmonary function tests?
they are a broad range of tests that measure how well the lungs take in and exhale air and how efficiently they transfer oxygen into the blood
what does spirometry measure?
measures how well the lungs exhale
what tests are used to identify abnormal lung function?
pulmonary function tests
what types of lung diseases are pulmonary function tests used to diagnose?
asthma, bronchitis and emphysema
abnormal lung function
some lung diseases can make the lungs contain too much air and take longer to empty, these lung diseases are called obstructive lung disorders
what does a pulmonary function test demonstrate?
a decrease in the forced vital capacity
what are the main symptoms of restrictive lung diseases?
shortness of breath and cough
what are restrictive lung diseases?
a category of extra pulmonary, pleural or parenchymal respiratory disease that restrict lung expansion
what do restrictive lung diseases result in?
decreased lung volume, an increased work of breathing, and inadequate ventilation and inadequate oxygenation
types of obstructive lung disease
- asthma
- bronchiectasis
- bronchitis
- chronic obstructive pulmonary disease
what are obstructive lung diseases?
a category of respiratory disease characterised by airway obstruction
what does many obstructive lung diseases result from?
the obstruction of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself
what obstructive lung diseases generally characterised by?
inflamed and easily collapsible airways, obstruction to airflow, problems exhaling and frequent medical clinic visits and hospitalisations
what is the law of Laplace?
it is a law in physics that in medicine is applied own the physiology of blood flow
state the law
state the law of Laplace?
under equilibrium conditions the pressure tangent to the circumference of a vessel storing or transmitting fluid equals the product of the pressure across the wall and the radius of the vessel for a sphere and half this for a tube
where is surfactant secreted to?
the alveolar space
what is the main function of surfactant?
to lower the surface tension of the air/liquid interface within the alveoli of the lung
what does surfactant do?
it reduces the surface tension of fluid in the lungs and helps male the small air sacs in the lungs (alveoli) more stable
what does reducing the surface tension help with?
keeps the small air sacs from collapsing when an individual exhales
