Bibliographic record
Abstract
The function of the respiratory system is to exchange O 2 and CO 2 with the blood. To understand this system from a bioengineering viewpoint, we will first discuss the gross anatomy of the lungs and their associated structures, and then discuss the mechanics of breathing. Gross anatomy We divide the respiratory system into two subsystems: the conducting airways and the associated structures . The conducting airways and pulmonary vasculature The conducting airways form a fantastically complex branching tree designed to transport air efficiently into the alveoli , the smallest air-filled structures in the lung where blood/gas exchange takes place. Air enters through the mouth or nose then passes through (in order): the pharynx (the throat), the larynx (the voice box), and the trachea (the large tube passing down the neck). The trachea splits to form two bronchi (singular: bronchus ), each of which feed air to one of the lungs (Fig. 7.1, color plate). Each bronchus splits to form bronchioles , which, in turn, split to form smaller bronchioles, and so on (Fig. 7.2). After about 16 levels of branching, we reach the terminal bronchioles , which are the smallest structures that have a purely air-conducting function, that is, in which essentially no blood/gas exchange takes place (Fig. 7.3). In adult lungs, the structures distal to the terminal bronchioles consist of several generations of respiratory bronchioles, alveolar ducts and alveolar sacs , which collectively are known as the acinus ; this is where the gas exchange occurs (Fig. 7.4).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.045 | 0.032 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".