Lecture 12 Unit 2 Flashcards
what is pulmonary ventilation
refers to the alternating flow of air into and out of the lungs
what is pulmonary ventilation due to
the actions of various respiratory muscles
what do inspiratory muscles do
expand the rib cage during inspiration and drive airflow into the lungs
what do expiratory muscles do
depress the rib cage and force air out of the lungs
what is the thoracic cage
the skeletal portion of the thorax
what is in the thoracic cage
ribs, coastal cartilages, thoracic vertebrae, and sternum
what are respiratory mechanics
the study of how the respiratory muscles move the rib cage
what is the respiratory pump
refers to the respiratory muscles, rib cage, pleural membranes, and lung elastic tissues
what is the diaphragm
the primary inspiratory muscle
what do the external intercostal muscle do
move ribs upward and outward expanding the rib cage
what does the sternocleidomastoid do
elevates the sternum
what do the scalenes do
elevate the top two ribs
what are inspiratory muscles
- diaphragm
- external intercostal muscles
- sternocleidomastoid
- scalenes
what are the expiratory muscles
- internal intercostals
- abdominal muscles
what do internal intercostal muscles do
muscles pull ribs downward and inward reducing the diameter of the rib cage
what do the abdominal muscles do
depress the lower ribs and elevate the diaphragm by increasing abdominal pressure
what does breathing or ventilation depend on
periodic pressure changes in the lungs
when does inspiration/ inhalation occur?
when pressure in the lungs becomes lower than the pressure in the atmopshere
when does expiration/ exhalation occur?
when pressure in the lungs is higher than the pressure in the atmosphere
what do pressure changes in the lungs depend on
pleural membranes
what happens during inspiration
the parietal pleura is pulled outward and the visceral pleura and lungs move with it
what is Boyle’s gas law?
the pressure exerted by a gas at constant temperature varies inversely with the volume of the gas