Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Describe how the structures of the lungs and thoracic cavity control the mechanics of breathingExplain the importance of compliance and resistance in the lungsDiscuss problems that may arise due to a V/Q mismatch

By the end of this section, you will be able to:Describe the passage of air from the outside environment to the lungsExplain how the lungs are protected from particulate matter

Students are introduced to the respiratory system, the lungs and air. They learn about how the lungs and diaphragm work, how air pollution affects lungs and respiratory functions, some widespread respiratory problems, and how engineers help us stay healthy by designing machines and medicines that support respiratory health and function.

In this activity, learners work in teams to construct human lung models from small plastic beverage bottles and balloons. Learners use the models to investigate how movements of the diaphragm cause lungs to inflate. This activity can be enhanced by sharing the "Health Hazards of Lunar Dust" Podcast with learners (see related resource link). This resource includes background information and variation ideas.

The Diaphragm is a dome-shaped musculotendinous sheet separating the thoracic and abdominal cavities. It is convex on its cranial surface. In the neutral position between full inspiration and full expiration, the most cranial part of the diaphragm is in line with the 6th rib.

By the end of this section, you will be able to:Describe the passage of air from the outside environment to the lungsExplain how the lungs are protected from particulate matter

Students explore the inhalation/exhalation process that occurs in the lungs during respiration. Using everyday materials, each student team creates a model pair of lungs.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"A new clinical trial suggests levosimendan could improve respiratory function in patients with amyotrophic lateral sclerosis. ALS is an adult-onset neurodegenerative disease that results in progressive weakness. Those affected by the disease typically die within three to four years of diagnosis due to respiratory failure commonly resulting from weakening of the diaphragm. Prior studies indicate that levosimendan – a calcium sensitizer on the market since 2000 for the treatment of acute worsening of severe heart failure – can also boost the force and efficiency with which the diaphragm contracts. This prompted researchers to investigate whether levosimendan is clinically beneficial to those with ALS. The phase 2 trial used a randomized, double-blind, placebo-controlled, crossover design to evaluate the efficacy and safety of oral levosimendan in 66 patients with ALS..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

Edited for Human Breathing OnlyBy the end of this section, you will be able to:Describe how the structures of the lungs and thoracic cavity control the mechanics of breathingExplain the importance of compliance and resistance in the lungsDiscuss problems that may arise due to a V/Q mismatch

To gain a better understanding of the roles and functions of components of the human respiratory system and our need for clean air, students construct model lungs that include a diaphragm and chest cavity. They see how air moving in and out of the lungs coincides with diaphragm movement. Then student teams design and build a prototype face mask pollution filter. They use their model lungs to evaluate their prototypes to design requirements.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"The diaphragm aids in breathing and swallowing and influences the sympathetic nervous system. However, trauma from cardiac surgery and conditions like heart attacks can impair diaphragm function. A simple new test may help clinicians assess this critical muscle quickly and without instruments. The test, called the Bordoni diaphragmatic test (BDT), consists of two phases. In the first phase, the patient rhythmically lifts their knees while standing with hands on hips and eyes closed. Two knee lifts are conducted with deep breaths, and two more are conducted with normal breaths. If the diaphragm is functioning correctly, the patient’s balance should be better with deep breathing. The second phase is performed in the same way but with resistance from the tester’s hand. A patient with a healthy diaphragm should lift their legs more forcefully while inhaling deeply than while inhaling normally..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.