Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Terminal nitrogen rise

C J Martin, S Das, A C Young

    Journal of Applied Physiology
    |October 1, 1976
    PubMed
    Summary
    This summary is machine-generated.

    A terminal nitrogen rise (TNR) during lung emptying is explained by a four-compartment model. This phenomenon occurs when flow from a poorly ventilated lung compartment increases relative to others.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    A survey of image-guided radiation therapy practices around the globe.

    Annals of the ICRP·2026
    Same author

    The case for individualisation of radiological protection in medicine.

    Annals of the ICRP·2026
    Same author

    The determination of coefficients for size specific effective dose for adult and pediatric patients undergoing routine computed tomography examinations.

    Journal of radiological protection : official journal of the Society for Radiological Protection·2024
    Same author

    Implications of tree expansion in shrubland ecosystems for two generalist avian predators.

    PloS one·2023
    Same author

    Variations in size-specific effective dose with patient stature and beam width for kV cone beam CT imaging in radiotherapy.

    Journal of radiological protection : official journal of the Society for Radiological Protection·2022
    Same author

    Successful treatment of a chronic oroantral fistula infected with extensively drug resistant bacteria using long-term oesophageal tube feeding and several non-conventional treatments in a horse.

    Australian veterinary journal·2021

    Area of Science:

    • Pulmonary Physiology
    • Respiratory Mechanics

    Background:

    • Nitrogen washout studies are crucial for understanding lung ventilation distribution.
    • A terminal nitrogen rise (TNR) is an observed phenomenon during forced expiration.
    • Previous models have not fully explained the mechanisms behind TNR.

    Purpose of the Study:

    • To investigate the physiological basis of the terminal nitrogen rise (TNR) observed during nitrogen washout.
    • To develop and validate a multi-compartment model that can simulate TNR.
    • To explore the influence of body position and lung volume on TNR.

    Main Methods:

    • Eighteen-breath nitrogen washouts were conducted on human subjects.
    • A four-compartment lung model was used to simulate washout data.
    • Subjects were studied in supine, seated, and head-down positions.

    Related Experiment Videos

  • Bronchospirometry with catheter sampling was performed on a second group.

    • Main Results:

    • The four-compartment model successfully simulated the observed TNR.
    • TNR occurred at similar lung volumes across different body positions.
    • TNR was observed at various lung levels, including subsegments.
    • TNR was linked to low transpulmonary pressure and rapid volume changes.
    • A terminal nitrogen fall was often observed after TNR.

    Conclusions:

    • TNR is explained by increased flow from a poorly ventilated compartment with high specific compliance at low lung volumes.
    • A large vertical hydrostatic gradient is not necessary for TNR.
    • The findings provide a new model for understanding ventilation heterogeneity during lung emptying.