Respiratory system Flashcards
(26 cards)
What are the structures of respiratory system?
Nares/nostrils Nasal cavity/nasal conchea Nasopharynx Oropharynx Laryngopharynx Epiglottis Larynx Trachea Bronchus Primary secondary tertiary Terminal bronchioles Respiratory bronchioles Alveolar duct Alveolus
What is boyles law? Principle of ventilation?
Volume of a gas is inversely proportional to pressure at a constant tempt
Air flows along a pressure gradient
How many lobes on each side?
Right has 3
Left has 2
What are main components of the respiratory membrane?
Endothelium cells of capillary
Epithelium cells of alveoli
Surfactant layer
Interstitial layer
What occurs with Ventilation?
Air in and out of lungs
Inspiration- pressure inside is less than outside
Expiration- pressure inside is greater than outside
Occurs through pressure gradient
Simple form of gas exchange?
External- lungs to blood
Internal- Blood to tissues
What happens with inspiration?
Contraction of muscles increases thoracic cavity volume
Quiet- uses diaphragm, external intercostals
Forced- sternocleidomastiod, serrated, scalene (accessory muscles of neck)
What happens in expiration?
Volume thoracic decreases
Quiet- passive process, relaxation of inspiratory muscles
Forced- active process, internal intercostals, abdominal muscles
What facilitates lungs to collapse?
Elastic recoil-Fibres in alveoli wall
Surface tension-Droplets between water and air at boundary
What opposes lung collapse?
Intrapleural pressure-Resists natural recoil
Surfactant-Decrease surface tension
What is compliance?
Increased compliance- allows greater expansion of thoracic cavity eg. Emphysema
Decreased compliance- harder to inflate lungs eg. Airway obstructions/asthma, pulmonary oedema, copd, fibrosis, musculoskeletal probs
What is tidal volume?
Air either inspired or expired from lungs normally
500mls
What is inspiratory reserve volume?
Amount of air inspired forcefully after normal tidal volume inspiration
3100ml
What is expiratory reserve volume?
Amount of forceful expired air after normal tidal volume expiration
1200ml
What is vital capacity?
Max. expelled air from lungs after Max. inspiration.
Sum = tidal volume
Inspiratory/expiratory reserve volume
4800ml
What is residual volume?
Air left in lungs after total expiration possible
1200ml
What is lung capacity?
Total volume of air lungs can hold
Sum= tidal volume
Inspiratory/expiratory reserve volume
Residual volume
6000mlHow does gas diffuse?
From high concentration to low concentration
What happens with oxygen transport?
- 5% attach to heamoglobin
1. 5% attach to plasma
How does co2 transport?
7% dissolved in plasma
23% attach to heamoglobin
70% transforms to bicarbonate ions
What is co2?
By-product of metabolism ?????
Metabolised in tissues/cells
What happens in co2 Tx?
Co2 leaves cells into blood circulation, where 23% attaches to haemoglobin and 70% transforms into bicarbonate ions.
Co2 = cabamino haemoglobin
Bicarbonate = Combines with H2O by carbonic anhydrase creating h2co3= carbonic acid. This results in separation and forming bicarbonate ions plus hydrogen, HCO3 & H+.
How is respiration controlled?
Chemoreceptors in brainstem (pons, medulla oblongata) pick up extra hydrogen in circulation (meaning increase in CO2) therefore sending message down intercostal nerves and phrenic nerves to diaphragm, increasing RR and effort/force.
If there’s a decrease of hydrogen, RR decreases along with effort/force
What is emphysema?
Pink puffer
Increased compliance/trapped air in lungs
Decreased/destruction elasticity of alveoli
Enlarged alveoli
Alveolar capillaries are destroyed
Barrel chest
Tripod posture
