Respiratory 6 and 7 Flashcards
What are the only muscles that are active during quiet inspiration?
- Diaphragm
- External intercostals
- Parasternal intercostals
How is the contraction of the diaphragm affected by forced breathing?
There is a stronger contraction
Which muscles are not recruited during resting level expiration?
The abdominal and intercostal muscles
What allows for expiration at resting levels?
The inspiratory muscles relax and air moves out of the lungs
What is the difference between quiet exhalation and forced exhalation?
During quiet exhalation, not muscles are recruited and during forced exhalation muscles are used
What happens with the abdominal muscles during forced expiration?
The abdominal muscles contract causing the abdominal content to be pushed is so that the diaphragm is moved even higher than it is at resting level so that more air can be expelled
What muscles are recruited during forced expiration and what do they do?
- Abdominal muscles to push abdominal contents down
* Internal intercostal muscles to push the ribcage down
Which muscles contribute to opening the upper airways?
- Tongue protruders
- Alae nasi
- Pharyngeal and laryngeal dilators (inspiratory)
- Pharyngeal and laryngeal constrictors (expiratory)
What is the main focus of the upper airway muscles?
To keep the airways open
What are the upper airway muscle dependent on?
State
When does the activity of the upper airways muscles become depressed?
During sleep
What occurs in obstructive sleep apnea?
The tone of the upper respiratory muscles is depressed and they become a floppy muscle not allowing air to pass through
Why does obstructive sleep apnea occur?
Due to problems with neural control in breathing. Lack of excitatory drive needed to maintain the tone of the respiratory muscles. Or in children with anatomical defects
What are the Conducting airways lined by?
A superficial layer of epithelial cells
•Mucus-producing goblet cells
•Ciliated cells
What is the function of the superficial layer of epithelial cells in the conducting airways?
They entrap inhaled biological and inert particulates and remove them from the airways
What is the filtering action of the conducting zone celled?
The Mucociliary Escalator
What does effective clearance of deposited particles in the airway require?
Ciliary activity and respiratory tract fluids
What fluid do ciliated cells produce?
Periciliary fluid
What makes up the SOL layer?
Periciliary fluid produced by ciliated cells
What is the density of the SOL layer?
It has a low density and viscosity
What does the low density of the SOL layer allow for?
The cilia to move freely in the fluid
What do the Goblet cells produce?
A dense mucus called the gel layer
In which direction do the cilia move in the Nasopharynx and the Trachea?
Downward in the Nasopharynx and upward in the trachea
What is the distribution like of the gel layer produced by goblet cells?
It is distributed in patches
How are the things trapped in the mucus layer removed?
Through cilia movements
Why do people who smoke have a consistent cough?
Because smoke reduces the activity of cilia and increases the number of goblet cells
Besides mucus, what is the other mechanism of filtering action in the respiratory system?
Macrophages present in alveoli
What kind of particulates arrive at the alveoli?
Only the smallest particulates
What is the last defense to inhaled particles?
Macrophages in the alveoli
What occurs with macrophages and silica dust or asbestos?
The macrophages ingest the particles but because they are very sharp they end up killing the macrophage
What happens after a macrophage is killed by silica dust in the alveoli?
The macrophage then disintegrate and release chemotactic factors promoting the recruitment of fibroblasts which introduce collagen which creates stiffness of the lungs developing pulmonary fibrosis
