cardio-respiratory system Flashcards
What are the 3 functions of the respiratory system?
- ventilation (external)
- gas exchange (external and internal)
- oxygen utilization (internal)
What’s the role of the pulmonary alveoli?
Where gas exchange occurs
Why is there a large amount of pulmonary alveoli?
Creates large surface area for efficiency and effectivity
What are the two types of alveolar cells and their functions?
Type 1: thin; where gas exchange occurs
Type 2: secrete pulmonary surfactant; prevent fluid buildup in the alveoli
What are the components of the conducting zone?
trachea, primary bronchus (left and right), terminal bronchioles
What are the components of the respiratory zone?
respiratory bronchioles, alveolar sacs, alveoli
What’s the role of the respiratory zone?
responsible for gas exchange
What’s the role of the conducting zone?
sending air to the respiratory zone, as well as warming, humidifying, as well as mucociliary cleaning (mucus filters small particles and clears them by propelling mucus to the pharynx to be swallowed).
How does air enter the trachea?
passes through the glottis found between the folds of the larynx (vocal chords)
What’s the thoracic cavity?
cavity above the diaphragm
What’s the role of the parietal pleura and visceral pleura?
keep the lungs connected to the thoracic wall; they also produce a mucus-rich pleural fluid that fils the space between the two membranes (pleural space)
What’s a pneumothorax?
a collapsed lung; lung becomes disconnected from thoracic wall, resulting in a large intrapleural space.
What are the 3 physical properties of the lungs?
- compliance: must be distensible
- elasticity: must return to original size after being distended
- surface tension: fluid in alveoli act to collapse the alveolus due to bonds between water molecules, and increase the pressure of air within (law of laplace)
What is lung compliance?
change in lung volume per change in transpulmonary pressure (∆V / ∆P)
What is surfactant?
substance (mostly made of phospholipids) in alveolar fluid that reduces surface tension; it prevents H-bonds between water molecules (most effective during expiration)
What is Respiratory Distress Syndrome?
disorder common in premature newborns due to production of surfactant late in fetal development; babies struggle to get oxygen due to collapsed alveoli
What are the components of pulmonary ventillation?
inspiration and expiration
What muscles are essential for inspiration?
- sternocleidomastoid (laboured breathing only)
- scalenes (laboured breathing only)
- external intercostals
- parasternal intercostals
- diaphragm
What muscles are essential for expiration?
- internal intercostals
- abdominal muscles
What happens during inspiration?
- diaphragm lowers and flattens as it contracts
- external and parasternal intercostal muscles contract, raising the ribs and increasing thoracic volume
- sternocleidomastoid and scalenes elevate ribs in an anteroposterior direction, making intercostals more effective (in laboured breathing only)
> overall, intrapulmonary pressure decreases, causing air to flood into the lungs