2 - Exercise physiology Flashcards
List the principle structures of the ventilatory system
- Nose
- Mouth
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Lungs
- Alveoli
Explain the pathway of oxygen
1) Oxygen rich air in breathed in through conducting airways (nasal and oral passage) and larger airways (trachea and bronchi). No gas exchange takes place here but the air is warmed, moistened and filtered by the lining of the airways.
2) Airways branch into smaller bronchioles and then into smaller air sacs called alveoli.
3) Gaseous exchange takes place here, the lungs are ideally designed for gaseous exchange
What pressure does air travel from to pressure
Air will flow from areas of HIGH PRESSURE LOW PRESSURE
Outline the functions of conducting airways
- Low resistance pathway of air
- Defense against chemicals and other harmful substances that are inhaled
- Warming and moistening the air
Functions of the nose, Pharynx and Larynx :
Nose:Humidifies the air entering and filters particles (thanks to the Vibrissae).
Pharynx:Air then passes through the 3 parts of the pharynx which offers a low resistance path for airflow into the larynx and then finally into the trachea.
Larynx:In addition to its function as the ‘voice box’ it also protects the trachea from invasion of foods and fluids.
Explain the mechanics of breathing in the lungs
- Inhalation -
Air: Air moves inwards
Pressure: Decreases
Volume: Increases
Diaphragm: Contracts and flattens
Intercostal muscles: contract
Chest cavity: Move up and outwards
- Exhalation -
Air: Air moves outwards
Pressure: Increases
Volume: Decreases
Diaphragm: Relaxes and recoils
Intercostal muscles: relax
Chest cavity: Moves down and inwards
The mechanics of breathing during exercise effects
- Increase in heart rate
- rate and depth of breathing increase
- Lowers pH in the blood
- Rate and depth of breathing increase due to detection of increased CO2 levels by chemoreceptors
Pulmonary ventilation (breathing)
inflow and outflow of air between the lungs and atmosphere
Total lung capacity
Volume of air in lungs after maximum inhalation
Vital capacity
Maximum volume of air exhaled after maximum inhalation
Tidal volume
Volume of air breathed in and out in one breath
Expiratory reserve volume
Additional volume of air in excess of tidal volume that can be forcefully exhaled
Inspiratory reserve volume
Additional volume of air in excess of tidal volume that can be forcefully inhaled
Residual volume
Volume of air still contained in the lungs after maximum exhalation
Minute ventilation
and calculation
Volume of air breathed out in one minute
Minute ventilation = Tidal volume x breaths per minute
What system is breathing controlled by and where does it report to?
Breathing is controlled by the nervous system, all reports to the medulla oblongata …
The nervous control and chemical control of the ventilation system
Nervous:
- Stretch receptors – Prevent over-inflation of the lungs, once stretching too much they send signals to the respiratory Centre in the medulla oblongata to reduce inflation
- Proprioceptors – Detect increase in movement
- Chemoreceptors –Detect increase in blood acidity
- Baroreceptors – Detect increase in blood pressure
Chemical:
Ventilation increases as a direct result of increases in blood acidity levels (lowers PH) due to increased carbon dioxide content of blood detected by the respiratory center. This results in an increase in rate and depth of breathing.