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:Explain the processes of digestion and absorptionCompare and contrast different types of digestive systemsExplain the specialized functions of the organs involved in processing food in the bodyDescribe the ways in which organs work together to digest food and absorb nutrients

Nachos are great...if you are among the lucky ones whose bodies can digest them. When digestion goes according to plan, the small intestine performs most of your chemical digestion in the duodenum, while accessory organs including the liver, gallbladder, and pancreas contribute enzymes that all but finish the job. Then your large intestine, which is actually shorter than the small intestine, tries to extract the last bit of nutrition, including the occasional attempt to turn nachos into energy, which for most humans, ends in gassy failure.

Chapters:
Introduction: Lactose Intolerance
The Small Intestine
Parts of the Small Intestine: Duodenum, Jejunum, Ileum
The Duodenum
The Liver
The Gallbladder
The Pancreas
The Large Intestine
Why Nachos Might Make You Gassy
How Do We Poop?
Review
Credits

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:

"Cost of feed is a major expense in chicken production, and that cost has been increasing due to overlap with human food and biofuel production. Therefore, improving feed efficiency can help reduce costs in chicken production systems. Both host genetics and gut microbiota can influence phenotypic traits like feed efficiency. New research explored this relationship in meat-type chickens by examining the host genetics as well as the microbiota from four intestinal regions and feces. Host relatedness showed little correlation to microbial community, but specific host genetic markers were associated with a small number of gut microbes. The greatest effect on feed efficiency, measured by residual feed intake (RFI), was host genetics. Out of the microbiota examined, only the cecum had a significant effect on the observed variance in RFI. Researchers also identified six bacterial groups associated with significant differences in feed efficiency..."

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

The jejunum continues from the duodenum and leads into the ileum. It is the longest part of the small intestine and is highly coiled. It has digestive and absorptive functions.

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:

"Fecal microbiota transplantation (FMT) is the transfer of fecal microbes from a healthy donor to a recipient with disease, the goal being to restore the composition and functionality of therecipient’s intestinal microbial community. One possible drawback of FMT is that feces largely contain microbes from the large intestine but not from the small intestine. A new study shows that this imbalance could limit the potential health benefits of FMT. The reason is that microbe colonization in the gut tends to be highly compartmentalized. Experiments showed that microbes transferred from donor pigs tended to colonize the same regions of the gut in recipient mice. Large-intestine microbes colonized the large intestine, and small-intestine microbes colonized the small intestine. Compared with FMT, this “whole-intestine” microbiota transplantation (WIMT) introduced more microbes derived from the small intestine, as predicted..."

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:

"Farmed chickens often suffer from intestinal inflammation which negatively affects their feed intake, digestion, and growth performance. The gut microbial community has a known close relationship with growth performance, but how, or if, this microbiota influences intestinal inflammation is not yet known. To test this, researchers examined the microbiota in young chickens, focusing on the jejunum section of the gut. They found that 7-week-old chickens with high body weight tended to have a microbiota dominated by gram-positive bacteria, like Lactobacilli. But lower-body-weight chickens had a microbiota dominated by gram-negative bacteria, like Escherichia-Shigella. Gram-negative bacteria carry endotoxin (lipopolysaccharide), and consequently, these lower body weight chickens had more of it in their bloodstream. These elevated lipopolysaccharide levels activated inflammatory cytokines in the jejunum, causing damage to the gut barrier..."

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