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 physical and chemical immune barriersExplain immediate and induced innate immune responsesDiscuss natural killer cellsDescribe major histocompatibility class I moleculesSummarize how the proteins in a complement system function to destroy extracellular pathogens

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:

"Even with antibiotics, severe pneumonia can lead to sepsis and death. Researchers in Germany have now identified a promising new therapy that may improve outcomes. Reporting in the journal Anesthesiology, the scientists indicate that targeting C5a, a component of the body’s complement system, may be a novel adjunctive therapy for severe pneumonia. One reason why patients don’t fare well with Streptococcus pneumoniae is that their highly activated immune system can damage tissue as it tries to clear the pathogen from the body. An important part of the body's first-line immune defense is the complement system, plasma proteins that patrol the body and coordinate with immune cells to kill invading bacteria. For example, when complement protein C5 is cleaved into C5a and C5b, C5b goes on to poke holes in bacteria. The smaller C5a is pro-inflammatory, attracting and activating neutrophils and making blood vessel walls more permeable to immune cells..."

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

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:

"Neuromyelitis optica spectrum disorder, or NMOSD, is a rare auto-immune demyelinating disease of the central nervous system. Now considered a separate disorder from multiple sclerosis, NMOSD can be severely disabling and life-threatening, with a reported mortality of between 7 and 32%. The hallmark of the disease is recurrent attacks of optic neuritis and/or transverse myelitis that result in accumulating, irreversible disability, including blindness and paraplegia. Approximately 75 to 90% of patients with NMOSD have a disease-specific, pathogenic IgG autoantibody against the aquaporin-4 water channel, or AQP4. This antibody is thought to bind to AQP4 on astrocyte foot processes at the blood-brain barrier. This causes damage to astrocytes and the blood-brain barrier itself through several mechanisms, including the formation of the membrane attack complex through activation of the complement component C5b9..."

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

This lesson describes the major components and functions of the immune system and the role of engineers in keeping the body healthy (e.g., vaccinations and antibiotics, among other things). This lesson also discusses how an astronaut's immune system is suppressed during spaceflight due to stress and other environmental factors.