Lab 4-- Respiratory Flashcards
Conducting portion
Nasal Cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
functional components
The airways
Alveoli
Blood vessels of the lungs
Tissue of the chest wall
Diaphragm
Respiratory control neurons in the brain stem
Respiratory portion
- alveoli (site of gas exchange)
- blood gas barrier is ideal because very thin and large surface area
- composed of alveolar epithelium, basement membranes, interstitium and capillary
endothelium
receptors in respiratory system
- B2 adrenergic
- M3 muscarinic
- smooth muscle tissue and epithelial tissue
Ventilation
- transport of air from the environment to the gas exchange surface in the alveoli
oxygen diffusion
- from the
alveolar air space across the
alveolar-capillary membrane to
the blood and to the
tissues
removal of carbon dioxide
- diffusion from the tissues to the
alveoli
Active process
Inspiration
Diaphragm: Convex at rest, flattens during contraction elongating the thoracic
cavity
- External Intercostals: Contraction lifts the ribs upwards and outwards,
expanding thoracic cavity, important for deep inhalations
- Accessory muscles of respiration: scalene, sternocleidomastoid
Passive process
Expiration
- Chest wall and lungs are elastic and naturally return to their resting state
- Expiratory muscles used only during exercise, forced expiration and disease states
- Abdominal muscles: rectus abdominis, internal and external obliques increases the abdominal pressure and pushes the diaphragm up, drawing air out of lungs
- Internal intercostals muscles: pull the ribs down and inwards decreasing the thoracic volume.
Mechanism of pulmonary ventilation
- When no movement (pressure inside and outside is equal)
- inhale (pressure inside decreases so air flows in)
- exhale ( pressure inside increases so air flows out)
Lung volumes
- tidal volume
- inspiratory reserve volume
- expiratory reserve volume
- residual volume
Tidal volume (Vt)
- volume of air in one inspired or expired normal breath
Inspiratory reserve volume (IRV)
- volume of air that can be inspired in excess of tidal volume
Expiratory reserve volume
- extra amount of air that can be expired after a normal tidal expiration
Residual volume
- volume of gas that remains after maximal expiration
Lung capacities
- total lung capacity
- vital capacity
- functional residual capacity
- inspiratory capacity
Total lung capacity
volume of gas that can be contained within a maximally inflated lung