Respiratory System OpenStax Notes
Every cell in the body needs to run the oxidative stages of cellular respiration (energy is produced).
- The release of carbon dioxide drives inhalation, not the need to take in oxygen.
The Major organs of the respiratory system function to provide oxygen to body tissues for respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance.
- Portions of the respiratory system are also used for non-vital functions, like sensing odors, speech, straining (childbirth/coughing)
Conducting zone
- Includes the organs and structures not involved in gas exchange
Respiratory zone
- Gas exchange organs and structures
Conducting Zone
- To provide a route for incoming and outgoing air, remove debris and pathogens from the incoming air, and warm/humidify the incoming air.
Root - region of the nose located between the eyebrows
Bridge - part of the nose that connects the root to the rest of the nose
Dorsum nasi - length of the nose
Apex - tip of the nose
Nostrils are formed by the alae (singular = ala). It is a cartilaginous structure that forms the lateral side of each naris (nares) or nostril
Philtrum - concave surface that connects the apex of the nose to the upper lip
\ Nasal bone - one pair of bones that lies under the root and bridge of the nose. It articulates superiorly with the frontal bone and laterally with the maxillary bones. Septal cartilage is flexible hyaline cartilage connected to the nasal bone, forming the dorsum nasi.
Alar cartilage - apex of the nose, surrounds the naris.
Nasal septum - separates the left and right sections of the nasal cavity.
- It is formed by a portion of the septal cartilage and posteriorly by the perpendicular plate of the ethmoid bone and the thin vomer bones.
- Each lateral wall of the nasal cavity has three bony projections (superior, middle, and inferior nasal conchae)
Conchae serves to increase the surface area of the nasal cavity and to disrupt the flow of air as it enters the nose, causing air to bounce along the epithelium, where it is cleaned and warmed.
- Also conserve water and prevent dehydration of the nasal epithelium by trapping water during exhalation
The floor of the nasal cavity is made of the palate.
- Hard palate at the anterior region of the nasal cavity is bone
- The soft palate at the posterior portion of the nasal cavity is muscle tissue.
Air exits the nasal cavities via the internal nares and moves into the pharynx.
