Structure And Function Of The CVR System Flashcards
What are the key functions of the nasal cavity?
Filtration: traps bacteria and particles with hairs and cilia
Vascularisation: for warming air around the conchae
Humidification:: easing airflow and reducing tracheal irritation
Producing mucus: to trap debris and bacteria
What is the role of the upper respiratory tract?
Structure: complex, with a large surface area and rich blood supply
Prevention of debris: hairs and mucus prevent debris entering lungs
Swallowing assistance: assisted by the pharyngeal muscles
What are the main functions of the larynx?
Allows air to enter, protects the trachea
Aids with speech and coughing which helps clear debris
What structural feature of the trachea allows flexibility?
C-shaped hyaline cartilage keeps the airway open and allows for flexible movement
How are the bronchi structured for gas exchange?
Bronchi divisions: first 16 as “dead space” with minimal exchange
Gas exchange which occurs in generations 17-23, rich in capillary blood supply
What is the alveolar structure and function?
Structure: small air sacs with large surface area for gas exchange?
Capillary beds: allow for efficient oxygen and carbon dioxide exchange
COPD damages alveoli, reducing exchange efficiency
What are the main parts of lung anatomy?
Apex: top of the lung through the thoracic aperture
Base: Bottom which rests on the diaphragm
Hilum: connecting the lung to the heart and trachea
Lobes: right lung has three lobes, left has two for the heart
Fissures: these separate the lobes of lungs (right lung has horizontal and oblique fissures)
How does blood flow through the lungs?
Pulmonary arteries: deoxygenated blood from the heart to the lungs
Pulmonary veins: oxygenated blood from lungs to the heart
Bronchial arteries: supply the tissue of the bronchial wall
What are the pleura and what are their functions?
To protect and cushion the lungs
Pleural fluid reduces friction whilst breathing
Conditions: Pleurisy (inflammation) and pneumothorax (lung collapse) effect pleura
What is the difference between ventilation and respiration?
Ventilation: air movement in/out (inspiration and expiration)
Respiration: gas exchange between environment and tissues; regulates acid-base balance and supports metabolism
Define anatomic dead space
First 16 generations of conducting airways where no gas exchange occurs
List and define lung volumes
Tidal volume: air per breath cycle (~500 mL)
Inspiratory reserve volume (IRV): extra air inhaled after normal breath
Expiratory reserve volume (ERV): extra air exhaled after normal exhale
Residual volume: remaining air after maximum exhalation
What are lung capacities?
Total lung capacity (TLC): the maximum amount of air the lungs can hold
Vital capacity (VC): total air exhaled after max inhalation
How is gas transferred in the lungs?
Capillaries wrap around alveoli for oxygen and carbon dioxide exchange
Perfusion: blood flow reaching alveoli, greater in lower lobes when standing upright
Diffusion: Passive movement of gases along concentration gradients
What is a concentration gradient?
A concentration gradient is a region of space where the concentration of a substance changes. The stronger the concentration gradient, the faster the diffusion
