Atavistic muscles in human anatomy: Evolutionary origins and clinical implications.

The evolution and variations of human anatomy are of great interest to physicians and anatomists. Variations can be categorized as vestigial, accessory or atavistic structures. Vestigial muscles are frequently encountered structures that are normally present but have become rudimentary through evolution. Muscles that disappeared during evolution sometimes arise again, although rarely; such muscles are referred to as atavistic. They arise from failure of suppression of genetic loci. Some common atavistic muscles seen clinically are the extensor digitorum brevis manus, chondroepitrochlearis and plantaris. Atavistic muscles appear more frequently in the upper limb than in any other region of the human body. One explanation for the appearance of these muscles, mainly within the upper limbs, is based on the evolution of the complex upper extremities formed in humans today. Often, the presence of atavistic muscles is asymptomatic, but they can compromise the function of normal anatomical structures and complicate clinical situations if their presence is unknown. They can cause complications if they are confused with soft tissue pathology, if they compress or displace surrounding structures, or if they require an additional blood supply during times of exercise and stress. The purpose of this paper was to describe the common atavistic muscles, their hypothesized evolutionary origins, their potential complications and possible treatments for the diagnosing clinician.

Hypoplasia of the Tentorium Cerebelli: Case Report and Review of the Literature.

The second largest intracranial specialization of the dura mater, the tentorium cerebelli, is a transverse fold that partially separates the cerebellum and cerebral hemispheres. During routine dissection of the posterior cranial fossa, a left-sided hypoplastic region of the tentorium cerebelli was observed. This fenestration was seen at the posterior portion of the tentorium as a posteromedial strip of tissue rising vertically to interface with the falx cerebri. Although isolated cases of tentorial hypoplasia have been reported in, for example, cases of Chiari II malformation, we believe isolated fenestration of this membrane is very rare, especially in the absence of the Chiari II malformation. The current case adds to the sparse literature on isolated tentorial defects and might be of interest to neurosurgeons or clinicians who review intracranial imaging.

The effects of obesity on the human body, part I: Skin and musculoskeletal.

Obesity is a worldwide issue that many global health authorities consider a growing epidemic. Having a positive correlation between increases in the industrialization of processed foods and sedentary occupations as well as a lack of access to healthcare in poorer socioeconomic areas, obesity is a multifactorial disease affecting several organ systems. The tendency for obesity to cause detrimental changes to the human body is a focal point for healthcare providers to establish more effective clinical treatment and management plans. Implementing comprehensive global educational programs to decrease the prevalence of this unforgiving disease is imperative for a healthier future. Herein, we have provided a comprehensive review of the health effects of obesity upon the human body for the interest of many practicing clinicians managing this health crisis.

The effects of obesity on the human body part II: Nervous, respiratory, and lymphatic systems.

This second installment of The Effects of Obesity on the Human Body considers the nervous, respiratory, and lymphatic systems. Those with obesity face countless psychological hurdles in addition to the respiratory burden and widespread inflammation that can suppress the immune system, resulting in the accumulation of excess fluid in body tissues.

The effects of obesity on the human body part III: Cardiovascular, digestive, excretory, endocrine, and reproductive.

This third installment of The Effects of Obesity on the Human Body discusses the endocrine, digestive, reproductive, cardiovascular, and excretory systems. Obesity is known to upset hormonal balance, leading to widespread metabolic disorders involving organs such as the liver and pancreas. Furthermore, the hypersecretion of leptin from adipose tissue triggers various responses from the cardiovascular and gastrointestinal systems, with implications for energy and nutrient balance and uptake.

Sacral fractures: An updated and comprehensive review.

Sacral fractures are often underdiagnosed but are relatively frequent in the setting of pelvic ring injury. Causes include traumatic insults and osteoporosis. Sacral fractures have become more frequent owing to the growth of the elderly population worldwide as osteoporosis is an age-related disease. Misdiagnosed and neglected sacral fractures can result in chronic back pain, spine deformity, and instability. Unfortunately, the wide range of classification systems hinders adequate communication among clinicians. Therefore, a complete understanding of the pathology, and communication within the interdisciplinary team, are necessary to ensure adequate treatment and satisfactory clinical outcomes. The aim of this manuscript is to present the current knowledge available regarding classification systems, clinical assessment, decision-making factors, and current treatment options.

The inferior intercavernous sinus: An anatomical study with application to trans-sphenoidal approaches to the pituitary gland.

OBJECTIVES: The inferior intercavernous sinus is located below the pituitary gland in the sella turcica. Its presence has been controversial among anatomists because it is not always found on radiological imaging or during cadaveric dissections; however, it is becoming a better-known structure in the neurosurgical and radiological fields, specifically with respect to transsphenoidal surgery. Therefore, the present study was performed to better elucidate this structure at the skull base. PATIENTS AND METHODS: Fifty adult, latex injected cadavers underwent dissection. The presence or absence of the inferior cavernous sinus was evaluated and when present, measurements of its width and length were made. Its connections with other intradural venous sinuses were also documented. RESULTS: An inferior intercavernous sinus was identified in 26 % of specimens. In all specimens, it communicated with the left and right cavernous sinus. The average width and length were 3 mm and 9.5 mm, respectively. In the sagittal plane, the inferior intercavernous sinus was positioned anteriorly in 31 %, at the nadir of the sella turcica in 38 %, and slightly posterior to the nadir of the sella turcica in 31 %. In two specimens (15.4 %), the sinus was plexiform in its shape. In one specimen a diploic vein connected the basilar venous plexus to the inferior intercavernous sinus on its deep surface. CONCLUSION: An improved understanding of the variable anatomy of the inferior intercavernous sinus is important in pathological, surgical, and radiological cases.

Anatomy, physiology, and updates on the clinical management of constipation.

Clinical management of constipation has evolved from the prescription of dietary supplements, to potent stimulant laxatives, to corrective surgeries for organic blockage. Yet constipation does not respond to a one-size-fits-all treatment. In recent decades, the Bristol Stool Form Scale and Rome III diagnostic criteria have allowed for algorithmic diagnosis, yet these criteria could benefit from further extension and meaningful discussion. This review incorporates pertinent clinical updates and uses the anatomy and physiology of constipation as helpful signposts for the practicing clinician.

The simian crease: Relationship to various genetic disorders.

The creases of the palm have been of interest for clinicians, anthropologists, and palmists for hundreds of years, but the variations in them have only been studied during the past 50 years. The simian crease, aptly named for its resemblance to the palmar creases of nonhuman simian primates, has received recognition clinically and anthropologically owing to its abnormal appearance and confounding cytogenetic etiology. Given the rarity of these palmar creases but also their usefulness in diagnosing congenital disorders, discussion of cases of those disorders could provide clinicians with further helpful diagnostic knowledge. This review of the literature focuses on the history, embryology, genetic and hereditary origins, and clinical significance of simian creases for the benefit of the diagnosing clinician. Clin. Anat. 32:1042-1047, 2019. © 2019 Wiley Periodicals, Inc.

A review of the clinical anatomy of hypertension.

Hypertension is defined as the persistent elevation of blood pressure above normal limits. It can be classified according to whether the contributing factors are genetics and environmental (primary hypertension) or underlying medical conditions and medications (secondary hypertension). The goal of this review is to increase recognition of the various anatomical etiologies of hypertension. Clin. Anat. 32:678-681, 2019. © 2019 Wiley Periodicals, Inc.