Respiration Flashcards
Covering: - Respiratory Mechanics
What is respiration mechanics? (2)
1) Study of mechanical properties of lung and chest wall
2) Process by which air enters and leaves the lungs
What are the basics of breathing? (2)
1) Lungs
What other systems interact with the respiratory system? (2)
1) Cardiovascular (pulmonary and peripheral)
2) Muscle system
Why is respiratory mechanics important? (3)
1) To understand how lungs work normally and in a diseased state
2) Almost all lung disease affect mechanical properties of lung
3) Death from lung disease usually due to inability to overcome changes in lung and/or chest mechanics
Breathing maintains…
blood gas homeostasis (02, CO2, pH)
At rest, what is the partial pressure of oxygen and carbon dioxide
P02 = 100+/-2 mmHg PC02 = 40+/-2 mmHG
At rest the exchange values of oxygen and carbon dioxide are
~ 250ml 02/min
~ 200ml 02/min
When walking 3mph the exchange values of oxygen and carbon dioxide are
~ 800ml 02/min
~ 750ml C02/min
During severe exercise the exchange values of oxygen and carbon dioxide are
~ 5000ml 02/min
~ 6000ml C02/min
What is the role of the nasal cavities and paranasal sinuses?
Filter, warm, humidify air, detect smells.
What is the role of the pharynx?
Conducts air to the larynx
What is the role of the larynx?
Protects opening to trachea and contains vocal cords
What is the role of the trachea?
Filters air, traps particles in mucus; cartilages keep airways open
What is the role of the bronchi?
Filters air, traps particles in mucus; cartilages keep airways open
What is the role of the lungs?
Responsible for air movement through volume changes during movement of ribs and diaphragm; including airways and alveoli
What is the role of the alveoli?
Act as a site of gas exchange between air and blood
What are the major functions of the upper airways? (3)
1) humidify (saturate with water)
2) Warm (to body temperature)
3) Filter
What type of epithelial cells line the upper airways to the bronchioles?
pseudo-stratified ciliated, columnar epithelium
What is the function of pseudo-stratified ciliated, columnar epithelium
To filter air/ trap dirt using mucus from goblet cells
What is the rate of ventilation at rest?
6L/min, ~12 breaths of 500ml
What is the max. ventilation?
160L/min, ~40 breaths of 4L
What is the rate of cardiac output at rest?
5L/min, 70bpm, 70ml/beat
What is max. cardiac output
25L/min, 200bpm, 125ml/beat
What are the steps in Quiet breathing?
Inspiration: Active
- diaphragm contracts (1cm)
- external intercostal muscles pull ribs outwards and upwards
- intra-pulmonary volume increases –> pressure decreases (-1)
- therefore pressure inside, lower then outside
- air moves down pressure gradient = breathe in
Expiration: Passive (elastic recoil)
- diaphragm relaxes
- intra-pulmonary volume decreases –> pressure increases
- therefore pressure inside is higher (+1) then outside
- air moves down pressure gradient = breath out
What are the steps in strenuous breathing?
Inspiration: Active
- diaphragm has greater contraction (10cm)
- external intercostal muscles have greater contraction
- accessory muscles are active:
- sternocleidomastoid
- alae nasi
- genioglossus
Expiration: Active abdominal muscles: - rectus abdominus - internal oblique - external oblique - transverse abdominus Internal intercostal muscles oppose external intercostals by pushing ribs down and inwards.
What are the muscles of inspiration?
- Diaphragm
- External intercostals
- Parasternal intercartilaginous muscles
- Scalenus (posterior, middle, anterior)
- Sternocleidomastoid
What are the muscles of expiration?
- Rectus abdominis
- External oblique
- Internal oblique
- Transverse abdominis
- Abdominal muscles
What type of muscle is the diaphragm?
skeletal muscle
What is intrapleural pressure (mmHg)?
Pressure change between lung and chest wall. Pressure always negative
What is tidal volume (ml)?
Volume of air going into lung during each breathe
