Describe the definitions
Tidal volume - normal air displaced between inspiration and expiration
Functional residual volume - Air present at the end of passive expiration
residual volume - volume of air in lungs after most forcible expiration
Vital capacity - After maximum inhalation the maximum volume of air that can be expelled following a forcful expiration
describe the Lobation of the lung
What are the two types of pleura ?
- Visceral pleura - attached to surface of lung, including fissures
- Parietal pleura - Derived from somatic mesoderm.
- Costal pleura - Inside the wall of the rib cage
- Mediastinum pleura - inside lateral wall of rib cage (mediastinum contents - heart and all vessels, oesphagus,trachea, phrenic nerves, thymus & lymph nodes)
- Diaphragmatic pleura - lines cranial surface of diaphragm
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Name the components of the conducting airways and respiratory zone
Conducting airways:
- trachea
- bronchi
- bronchioles
- terminal bronchioles
Respiratory zone:
- Respiratory bronchioles
- aveolar ducts
- aveolar sacs
What are clara cells
Cells of the bronchiolar epithelium which secrete surfactant. Not the same as type ll aveolar, they have anti inflammatory function
Describe specialisation of alveolar structure
- Shared septum - protects agains alveolar collapse
- Pores of khons - Gaps in alveolar septa which allow more efficient movement of inspired air. Also prevent lung from collapsing by equalizing pressure in adjacent alveolar
Whats the definition of compliance?
Change in volume/Change in pressure
What occurs during inspiration and expiration?
Inspiration :
- Phrenic nerve innervates diaphragm to flatten and enlarge thoracic cavity
- Ribs move outwards. Parietal pleura then move out, causing visceral pleura and the lungs outwards
- Pressure lowered
Expiration:
- Passive process
- Diaphragm relaxes, reducing thoracic volume
- Pressure increased and lung recoils expelling air
- Internal intercostals can help reduce thoracic volume
What resiratory problem are race horse prone to ?
Excercise induce pulmonary haemorrhage (EIPH)
Blood vessels burst under high pressure
What affect does a change in PH have on haemoglobin affinity?
- Decrease in PH (more acidic) leads to a decrease in affinity for oxygen. Therefore oxygen more readily deposited to tissues
- Increase in PH (alkaline) leads to increase in oxygen affinity. Therefore oxygen is less readily released by haemoglobin
