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 an open and closed circulatory systemDescribe interstitial fluid and hemolymphCompare and contrast the organization and evolution of the vertebrate circulatory system.

This lesson describes how the circulatory system works, including the heart, blood vessels and blood. Students learn about the chambers and valves of the heart, the difference between veins and arteries, and the different components of blood. This lesson also covers the technology engineers have developed to repair the heart if it is damaged. Students also understand how the circulatory system is affected during spaceflight (e.g., astronauts lose muscle in their heart during space travel).

Revised for Bio 101, Human Circulatory System, Errors in MC questions fixed.By the end of this section, you will be able to:Describe an open and closed circulatory systemDescribe interstitial fluid and hemolymphCompare and contrast the organization and evolution of the vertebrate circulatory system.

This lesson contains background about the blood vascular system and the heart. Also, the different sizes of capillaries, veins, and arteries, and how they affect blood flow through the system. We will then proceed to talk about the heart's function in the blood vascular system. This will lead into a discussion of heart valves, how they work and what might cause them to fail. Then we will discuss prosthetic heart valves.

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:

"Congenital heart defects (CHDs) are common, affecting 9 out of every 1000 babies born. CHDs are caused by various gene mutations that prevent the heart chambers and/or valves from forming properly. However, the precise mechanisms of chamber development and how they are dysregulated in fetuses with CHDs are unclear. To learn more, researchers recently investigated the molecular signals of heart development in a zebrafish animal model. They found that all heart cells expressed the gene sema3fb, which encodes the cell guidance cue Sema3fb. However, only ventricle-specified cells expressed the gene encoding this cue’s receptor, Plxna3, effectively restricting Sema3fb signaling to the ventricle. In zebrafish embryos with sema3fb mutations (ca305 and ca306), heart chamber development was impaired. Specifically, the atrium and ventricle were too small because the cells were shrunken, which caused the heart to pump less blood and fill with fluid..."

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