Anatomy and Physiology is a dynamic textbook for the two-semester human anatomy and physiology course for life science and allied health majors. The book is organized by body system and covers standard scope and sequence requirements. Its lucid text, strategically constructed art, career features, and links to external learning tools address the critical teaching and learning challenges in the course. The web-based version of Anatomy and Physiology also features links to surgical videos, histology, and interactive diagrams.

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 period shortly after birth is a critical window for microbiome establishment. Antibiotics can impact this process, often negatively, but most of the research to date has been conducted on full-term infants and has rarely included infants that never received antibiotics, complicating the analysis. A recent study sought to close these gaps and examined the skin and gut microbiomes of preterm infants. While gestational age at birth had some influence on the maturation of the microbiome, postnatal age had a stronger impact. But brief exposure to antibiotics reversed the maturation trajectory between weeks one and three after birth, and antibiotic exposure impacted the abundance of potentially beneficial gut microbes. Some bacteria in our microbiome generate short-chain fatty acids, like butyrate and acetate, that our cells can use, but at three weeks after birth, the antibiotic-exposed infants had an altered microbiome with reduced capacity to produce these important metabolites..."

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:

"Next-generation sequencing (NGS) studies have led to dramatic improvements in our understanding of human microbiomes. However, this method is based on the presence of DNA and cannot distinguish between living and dead microbes on its own. Environments like our skin are hostile and have high microbe turnover, which leads to significant amounts of DNA from dead microbes, which can lead to inaccurate community estimations in NGS studies. To overcome this, researchers tested the feasibility of pre-treatment with Benzonase to digest unprotected DNA. They used both mock bacterial communities and skin microbiome samples with inactivated bacteria or bacteria-free DNA spiked-in. Benzonase (BDA) pre-treatment reduced the levels of DNA from dead bacteria in both mock and natural communities. It also reduced the amount of host DNA in samples with high human-to-microbial DNA ratios without obvious impact on the microbial profile..."

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

This patient education program explains burns, the different degrees of burns, and how they may be treated. This resource is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute.

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 skin is the interface between the human body and the environment, and the different features in distinct skin regions, such as different temperatures, humidity levels, gland densities, and pH values, create a variety of niches that can support a diverse skin microbiome. This microbiome includes bacteria, archaea, viruses, fungi, and even mites. A healthy skin microbiome helps maintain skin homeostasis, protects against pathogens, communicates with and trains the immune system, and affects wound healing. However, the skin microbiome can be influenced by many factors, including intrinsic factors like aging and extrinsic factors like cosmetic. Recent advances in molecular biology techniques and next-generation sequencing have drastically increased our understanding of the microorganisms that live on our skin, but the microbes are often still difficult to culture and study..."

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:

"Skin microbes play fundamental roles in maintaining balance in the skin. An imbalance – microbial dysbiosis – is associated with the onset and progression of many common skin diseases. To better understand the functions of skin microbes, a recent study aimed to develop a catalog of skin microbiome reference genes. Using a sample of 822 skin samples from Han Chinese individuals, combined with 538 previously obtained North American samples, researchers constructed the integrated Human Skin Microbial Gene Catalog, or iHSMGC, comprising over 10 million genes. Using the catalog, they found that skin commensals such as Staphylococcus are an important reservoir of antibiotic resistance genes (ARGs). Microbe- and skin site-specific ARG signatures were identified, as were differences between populations. Two patterns of microbial networks – “cutotypes” – were identified in the newly analyzed samples, with Moraxella osloensis and Cutibacterium acnes serving as markers of the cutotypes..."

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

This design course targets the solution of clinical problems by use of implants and other medical devices. Topics include the systematic use of cell-matrix control volumes; the role of stress analysis in the design process; anatomic fit, shape and size of implants; selection of biomaterials; instrumentation for surgical implantation procedures; preclinical testing for safety and efficacy, including risk/benefit ratio assessment evaluation of clinical performance and design of clinical trials. Student project materials are drawn from orthopedic devices, soft tissue implants, artificial organs, and dental implants.

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:

"You leave traces on every surface you touch. These traces include parts of your unique skin microbiome, and the comparison of skin and surface microbiota has potential as a forensic tool. To test this concept, a recent study analyzed the metagenome left behind on surfaces by four people. People were matched to their household in 84% of the tests and their neighborhood in only 50% of tests. Matching accuracy decayed over the test period on public surfaces, but not in homes. Time of sample collection affected matching accuracy for both skin (reference) and surface samples (query). This may be driven by diurnal routines influencing microbial dispersal from these public surfaces. Returning home likely normalizes a person’s microbiome via contact with their household microbial reservoir. More research is needed with larger sample sizes and across a diverse range of situations to map out these effects and their mechanisms in more detail..."

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

There are various hormones that influence the structure of the skin. These influences may be made apparent by the repeated long-term administration of various glucocorticoids or their analogues. Endogenous imbalances are generally seen in adult mature animals although congenital forms have been seen, especially with hypothyroidism. The hormones implicated as important for maintaining skin structure are thyroxine, cortisol and estradiol. Deficiencies or excessive production may result from abberations in the function of the hypothalamic-adrenal axis, the adrenal gland, thyroid gland or the gonads.

To evaluate the different integumentary systems found in the animal kingdom, students conduct an exploratory research-based lab. During the activity, students create a model epidermis that contains phosphorescent powder and compare the results to a control model. After learning about the variations of integumentary systems—systems that comprise the skin and other appendages that act to protect animal bodies from damage—students act as engineers to mimic animal skin samples. Their goal is to create a skin sample that closely represents the animal they are mimicking while protecting the base ‘epidermis’ from UV light.

Students operate mock 3D bioprinters in order to print tissue constructs of bone, muscle and skin for a fictitious trauma patient, Bill. The model bioprinters are made from ordinary materials— cardboard, dowels, wood, spools, duct tape, zip ties and glue (constructed by the teacher or the students)—and use squeeze bags of icing to lay down tissue layers. Student groups apply what they learned about biological tissue composition and tissue engineering in the associated lesson to design and fabricate model replacement tissues. They tangibly learn about the technical aspects and challenges of 3D bioprinting technology, as well as great detail about the complex cellular composition of tissues. At activity end, teams present their prototype designs to the class.

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:

"Environmental pollution can have harsh effects on many systems in the body, but in addition to well-appreciated internal effects, pollutants can also harm our body’s outer barrier – our skin. Polyaromatic hydrocarbons (PAHs), organic molecules found in air pollution, can damage the skin. accelerating aging, altering skin pigmentation, and affecting pathways underlying acne and skin cancer. Unfortunately, exactly how PAH pollution harms the skin remains poorly understood. In a new study, researchers evaluated the cheek and scalp microbiota of over 200 individuals from two cities in China: one with high pollution levels and one with less PAH pollution. They found that individuals from the city with heavier pollution had higher PAH contamination of their skin, and certain bacteria were more prevalent in the high-PAH city, including some that contribute to skin conditions..."

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

The simplest way to avoid infection is to prevent microorganisms gaining access to the body. The skin has an external coating of dead cells (cuticle) that, when intact, is impermeable to most infectious agents as very few pathogens are capable of penetrating the thick stratified squamous epithelium of the skin (and lower urinary tract).

Students learn about the current applications and limitations of 3D bioprinting, as well as its amazing future potential. This lesson, and its fun associated activity, provides a unique way to review and explore concepts such as differing cell functions, multicellular organism complexity, and engineering design steps. As introduced through a PowerPoint® presentation, students learn about three different types of bioprinters, with a focus on the extrusion model. Then they learn the basics of tissue engineering and the steps to design printed tissues. This background information prepares students to conduct the associated activity in which they use mock-3D bioprinters composed of a desktop setup that uses bags of icing to “bioprint” replacement skin, bone and muscle for a fictitious trauma patient, Bill. A pre/post-quiz is also provided.

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:

"Antioxidants – considered by many the superheroes of the dietary world – are reported to do everything from improving heart health to helping fight cancer. They’re also a common anti-aging ingredient in skin care lines. University of Maryland researchers have narrowed down one antioxidant that seems to significantly outperform others in the anti-aging arena: methylene blue – a chemical used in research laboratories across the world. In a recent study published in Scientific Reports, the team showed that applying the molecule to a reconstructed skin model can slow or even reverse several well-known signs of aging, opening the door to new, more effective cosmetic treatments. The team compared the performance of methylene blue against three other popular antioxidants on skin cells collected from healthy young donors, elderly people, and individuals with progeria – a genetic condition that causes accelerated aging..."

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:

"Microbiomes share an intimate relationship with the organisms they colonize, even across evolutionary timescales. That’s the basis of a theory called phylosymbiosis. Phylosymbiosis holds that microbial communities evolve as their host evolves and has been confirmed to exist for certain insects and mammals. Researchers recently tested whether that relationship holds among fish. Approximately 420 million years ago, fish made an epic evolutionary split into elasmobranchs -- creatures with all-cartilage skeletons -- and bony fish. Since then, the two have accumulated vast differences in anatomy and physiology, most notably in their skin. That’s where the researchers zeroed in. For a small sample of fish, they used metagenomics to compare the makeup of microbial communities living on fish skin. Between fishes considered closely or distantly related in evolutionary terms, findings revealed that elasmobranchs displayed patterns of phylosymbiosis, while bony fish did not..."

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:

"Skin, the largest organ of the human body by weight, hosts a variety of microorganisms that can influence health. Skin microbes play a role in immunity, wound healing, colonization resistance, and skin disorders. Unfortunately, while mouse models have uncovered some host pathways influenced by skin microorganisms, more studies are needed in healthy human skin. A recent study uses a 3D skin tissue model – human skin equivalents – to study the effects of the microbiome on skin health. Researchers introduced bacterial isolates from healthy individuals to an in vitro skin model. Transcriptomics demonstrated that microbial presence on 3D skin tissue significantly altered patterns of gene expression in particular influencing genes involved in apoptosis, proliferation, and the extracellular matrix. Microbes also affected the thickness of the epidermal layer reduced the number of actively proliferating cells and increased filaggrin expression..."

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

The principles and practice of tissue engineering (and regenerative medicine) are taught by faculty of the Harvard-MIT Division of Health Sciences and Technology (HST) and Tsinghua University, Beijing, China. The principles underlying strategies for employing selected cells, biomaterial scaffolds, soluble regulators or their genes, and mechanical loading and culture conditions, for the regeneration of tissues and organs in vitro and in vivo are addressed. Differentiated cell types and stem cells are compared and contrasted for this application, as are natural and synthetic scaffolds. Methodology for the preparation of cells and scaffolds in practice is described. The rationale for employing selected growth factors is covered and the techniques for incorporating their genes into the scaffolds are examined. Discussion also addresses the influence of environmental factors including mechanical loading and culture conditions (e.g., static versus dynamic). Methods for fabricating tissue-engineered products and devices for implantation are taught. Examples of tissue engineering-based procedures currently employed clinically are analyzed as case studies.
Archived webcast lecture videos for the Fall 2008 version of this class can be found at the HST.535 Fall 2008 website.