Divergent otolithic systems in the inner ear of Paranthropus robustus and Australopithecus africanus.

The bony labyrinth of the inner ear houses the sensory end-organs responsible for balance (otolithic system in the utricle and saccule, and semicircular canal system) and hearing (cochlea). Study of the bony labyrinth has revealed considerable morphological diversity in the hominin lineage (semicircular canals and cochleae) and aided in reconstructing essential aspects of primate evolution, including positional behavior, audition, and phylogenic affinities. However, evidence of evolutionary change in the hominin otolithic system remains elusive.

Review of respiratory anatomy adaptations in whales.

Whales (cetaceans, including dolphins and porpoises) are superbly adapted to life in water, but retain vestiges of their terrestrial ancestry, particularly the need to breathe air. Their respiratory tract exhibits many differences from their closest relatives, the terrestrial artiodactyls (even toed ungulates). In this review, we describe the anatomy of cetacean respiratory adaptions.

First evolutionary insights into the human otolithic system.

The human otolithic system (utricle and saccule), housed within the bony vestibule of the inner ear, establishes our sense of balance in conjunction with the semicircular canals. Yet, while the morphological evolution of the semicircular canals is actively explored, comparative morphological analyses of the otolithic system are lacking. This is regrettable because functional links with head orientation suggest the otolithic system could be used to track postural change throughout human evolution and across primates more broadly.

A morphometric comparison of the ductus reuniens in humans and guinea pigs, with a note on its evolutionary importance.

The mammalian inner ear contains the sensory organs responsible for balance (semicircular canals, utricle, and saccule) and hearing (cochlea). While these organs are functionally distinct, there exists a critical structural connection between the two: the ductus reuniens (DR). Despite its functional importance, comparative descriptions of DR morphology are limited, hindering our understanding of the evolutionary diversification of hearing and balance systems among mammals.

Human dissection for anesthesiology resident training augments anatomical knowledge and clinical skills.

Anatomy is an essential component of clinical anesthesiology. The use of simulated patients and alternative materials, including embalmed human bodies, have become increasingly common during resident physician training due to the deemphasis on anatomical education during undergraduate medical training. In this report, the need for a more extensive review of relevant anatomy for the practice of anesthesiology was addressed by the design, evaluation, and dissemination of a human dissection course for procedural training of anesthesiology residents.

First evidence of the link between internal and external structure of the human inner ear otolith system using 3D morphometric modeling.

Our sense of balance is among the most central of our sensory systems, particularly in the evolution of human positional behavior. The peripheral vestibular system (PVS) comprises the organs responsible for this sense; the semicircular canals (detecting angular acceleration) and otolith organs (utricle and saccule; detecting linear acceleration, vibration, and head tilt). Reconstructing vestibular evolution in the human lineage, however, is problematic.

Insights into Inner Ear Function and Disease Through Novel Visualization of the Ductus Reuniens, a Seminal Communication Between Hearing and Balance Mechanisms.

The sensory end-organs responsible for hearing and balance in the mammalian inner ear are connected via a small membranous duct known as the ductus reuniens (also known as the reuniting duct (DR)). The DR serves as a vital nexus linking the hearing and balance systems by providing the only endolymphatic connection between the cochlea and vestibular labyrinth. Recent studies have hypothesized new roles of the DR in inner ear function and disease, but a lack of knowledge regarding its 3D morphology and spatial configuration precludes testing of such hypotheses.

Nasopharyngeal morphology contributes to understanding the "muddle in the middle" of the Pleistocene hominin fossil record.

The late archeologist Glynn Isaac first applied the term "muddle in the middle" to a poorly understood period in the Middle Pleistocene human fossil record. This study uses the nasopharyngeal boundaries as a source of traits that may inform this unclear period of human evolution. The nasopharynx lies at the nexus of several vital physiological systems, yet relatively little is known about its importance in human evolution.

Racism, structural racism, and the American Association for Anatomy: Initial report from a task force.

In 2021, the American Association for Anatomy (AAA) Board of Directors appointed a Task Force on Structural Racism to understand how the laws, rules, and practices in which the Association formed, developed and continues to exist affect membership and participation. This commentary is the first public report from the Task Force. We focus on African Americans with some comments on Jews and women, noting that all marginalized groups deserve study.