Ventilation to Breathing Patterns Flashcards
What are the 3 basic steps of respiration and describe them
- Ventilation= ie breathing, exchange of air between the atm and the alveoli
- External respiration= gas exchange between alveoli and blood in the pulmonary capillary
- Internal respiration= systemic exchange of gases in the capillaries and tissues
What is cellular respiration
the metabolic rxn inside the cell that makes ATP, consumes O2 and gives off CO2
Define intrapleural (intrathoracic) pressure
fluid pressure between the visceral and partial layers of the pleura
Define alveolar (intrapulmonic) pressure
pressure inside the lung
When pressure in the atmosphere is greater than in the alveolar (intrapulmonic) pressure
inspiration
What is Boyles law and how does it relate to ventilation
Boyles= In a container pressure is inversely related to volume
What are the main muscles of inspiration and what one is the most important
Diaphragm= most important
External intercostals
What happens when the diaphragm constricts
it flattens out increasing thoracic cavity volume which decreases pressure and allows inhalation
What is the role of the external intercostals
when they contract they elevate the ribs causing the anteroposterior and lateral diameters to increase
When the thoracic cavity increases in volume what allows the lungs to expand
Rib cage expands-> partial pleura expands and because of surface tension it pulls on the visceral pleura causing lung expansion
True or False the intrapleural pressure is always lower than atmospheric pressure
True
What muscles are used during deep forceful inhalations and what are there fx
Accessory muscles
- sternocleidomastoids- elevate sternum
- scalenes= elevates ribs 1 and 2
- pectoralis minor= elevates ribs 3-5
What part of ventilation is active and which part is passive
active= inhalation
passive= exhalation
What causes normal exhalation
recoil of the main muscles of inspiration, elastic fibers of the lungs, smooth muscles of the airway, and the inward pull of the alveolar fluid
What muscles are used during forceful exhalations and what are there fx
Abdominals= moves inferior ribs downward compressing the abd visera which pushes up on the diaphragm
Internal intercostals = pulls ribs inferiorly to help put pressure on the abd visera
What other factors contribute to the rate of airflow/pulmonary ventilation
- surface tension of the alveolar fluid
- compliance (stretch) of the lungs
- airway resistance (diameter)
What is the largest factor of elastic recoil in exhalation
the surface tension of alveolar fluid
What reduces the surface tension of alveolar fluid
surfactant
Define Law of Laplace and how does it relate to ventilation
States pressure inside a spherical surface is inversely proportional to its radius
so smaller alveoli have higher pressure that needs to be overcome
Describe respiratory distress syndrome
premature babies lack the ability to produce surfactant allowing alveolar collapse and reduced gas exchange
Define atelectasis
partial or complete collapse of the lung
If a pt has high lung compliance what does this mean
lungs and chest wall expands easily
If a pt has high lung compliance what does this mean
lungs and chest wall resist expansion
What can be said about the compliance of pts w/ COPD and Emphysema
the pts lung have decreased/low lung compliance which decreases area for gas exchange
