The mouth

The mouth is the common aperture to the aerodigestive tract. With the coordinated assistance of the tongue and lips it contributes to the formation of meaningful sound whilst the presence of intact dental arches allow for mastication. The oral cavity proper represents the atrium beyond the lips reaching to the palatoglossal arches posteriorly, where the oropharynx begins beyond the oropharnygeal isthmus. It is restricted by the cheeks laterally, the hard and soft palate superiorly and the mobile tongue resting on the mylohyoid muscle inferiorly. The paired major salivary glands drain into the oral cavity along with numerous minor salivary glands. The tongue is a thick, mucosa covered muscular structure concerned with mastication, taste, talking and swallowing. The palate is the roof of the mouth, separating the oral and nasal cavities and participating in speech and swallowing. It can be divided into two parts: a bony anterior hard palate and soft posterior palate.

EMG Analysis of Dominant and Non-Dominant Arm of Latissimus Dorsi Muscles in Bowlers of Karad, Maharashtra, India

BACKGROUND Latissimus dorsi plays an important role in bowlers. Different bowling techniques recruit latissimus dorsi at different phases of bowling. This causes the muscle to undergo excessive contraction than its limit. Despite widespread knowledge about the recruitment of latissimus dorsi in bowling, there is limited electromyographic (EMG) studies about latissimus dorsi. It is necessary to evaluate and document the recruitment of latissimus dorsi in dominant and non-dominant arm in bowlers, which is focused in this study. This study was done to analyse the surface EMG activity of latissimus dorsi muscle in dominant and non-dominant arm during bowling. METHODS A cross-sectional analytical study was carried out among 96 professional cricket bowlers from deluxe cricket club and Yashwanthrao Chavan’s cricket club in Karad. EMG electrodes were applied over the latissimus dorsi muscle and the bowlers were asked to perform the action of bowling. The root mean square (RMS) and mean peak amplitude of the dominant and non-dominant arm were recorded. RESULTS The RMS (12.45 ± 2.84) values and mean peak amplitude (131.77 ± 44.11) of the dominant latissimus dorsi varied significantly from non-dominant muscle (P = 0.0015). Wilcoxon test was utilized for analysis of within group parameters. CONCLUSIONS The result of the present study showed strong evidence to support high recruitment of dominant latissimus dorsi in professional bowlers suggests the changes occurred in the physiological as well as biomechanical muscular structure. KEY WORDS EMG, Dominant, Non-Dominant, Latissimus Dorsi, Fast Bowlers

Functional Changes of the Upper Esophageal Sphincter in Gastroesophageal Reflux

Introduction The upper esophageal sphincter (UES) is a muscular structure located at the transition from the pharynx to the esophagus, with the cricopharyngeal muscle as the most important component. During gastroesophageal reflux, the pressure in the UES elevates, which is apparently a protective mechanism to prevent esophagopharyngeal reflux and airway aspiration. In gastroesophageal reflux disease (GERD), there may be functional changes in the UES. Objective The objective of the present review was to determine UES functional changes in GERD. Data Synthesis In healthy individuals, gastroesophageal reflux causes an increase in the UES pressure. This response of the sphincter is at least partially impaired in patients with GERD. In the disease, the UES has a reduced length and decreased resting pressure. However, other publications found that in chronic gastroesophageal reflux the basal sphincter pressure increase, differences which may be consequent to the measurement method or to disease severity. The UES opening during swallowing has a smaller diameter, and the bolus transit time through the sphincter is longer. Conclusion The UES of patients with GERD does not open as expected and the bolus flow through the sphincter is longer. This behavior may be associated with dysphagia, a frequent complaint in patients with GERD.

Analysis and modeling of human seat interaction with a focus on the upper body and backrest using biomechanics and contact mechanics

BACKGROUND: This paper outlines a method to study the interaction between the human body and the aircraft seat concerning the seat comfort. METHOD: Firstly, the human body is modeled based on biomechanics and divided into a number of body segments connected by joints according to human anatomy. The angles between the body segments are obtained by curve fitting of the existing biomechanical research data. The contact forces between the human body and the seat are modeled using pairs of bi-lateral point forces. These forces are calculated and located through the analysis of the center of gravity of each body segment and average muscular structure of the human body. The geometry of the human and the seat is obtained from a 3D scan model or a CAD model. Secondly, the pressure distribution between the human body and the seat is modeled and calculated using the contact stress theory. The results of the two parts are combined to analyze the comfortability in relation to different postures, backrest recline angles and changing in shape and material. RESULTS: Simulations were performed and they are compared with experimental measurement and various FEM studies for validation. It is found that accuracy of this method is comparable with most FEM calculation. CONCLUSION: This method provides a new direction in cushion conform research. It is faster and convenient to use comparing to the FEM, and the result is reliable.

The artery of Mouchet: blood supply of the septomarginal trabecula in 50 human hearts

SUMMARY The septomarginal trabecula is a muscular structure which transmits the right branch of the atrioventricular bundle. It is usually supplied by a branch from the second anterior septal artery. Anastomoses between the right and left coronary arteries may happen on the septomarginal trabecula. They are of great significance in order to prevent ischemia during a myocardial infarction. Surgeries such as Konno's and Ross' procedures implies in knowledge of these vessels anatomy. The coronary arteries of 50 human hearts were injected with latex and subsequentely dissected with the purpose of identifying the arterial branch that supplied the septomarginal trabecula. The trabecular branch arose from the second anterior septal artery in 38% of cases, and the branch arose from the first anterior septal artery in 26%. One of the hearts had its septomarginal trabecula supplied by the conus arteriosus arteryliterature. Anastomoses between the right and left coronary arteries were found inside the septomarginal trabecula. The right branch of the atrioventricular bundle is subject to a great number of clinical conditions and is often manipulated during surgery, thus, the study of the septal branches of the coronary arteries and the trabecular branch is essential.

The anconeus epitrochlearis muscle may protect against the development of cubital tunnel syndrome: a preliminary study

OBJECTIVE The authors hypothesized that when the anatomical variant of an anconeus epitrochlearis is present, the risk of developing cubital tunnel syndrome would be reduced by replacing the normal roof of the cubital tunnel (Osborne's ligament) with a more forgiving muscular structure, the anconeus epitrochlearis. The authors further hypothesized that when the presence of an anconeus epitrochlearis contributes to ulnar neuropathy, it would be secondary to muscular hypertrophy, thereby making it more likely to occur in the dominant arm. Therefore, the goal of the present study was to evaluate these hypotheses. METHODS This retrospective cohort study was performed by reviewing the records of all adult patients who underwent operative intervention for cubital tunnel syndrome between 2005 and 2014 as the experimental group and all asymptomatic patients in the medical literature who were part of a series reporting the prevalence of an anconeus epitrochlearis as the control group. The primary outcome of interest was the presence of an anconeus epitrochlearis in asymptomatic individuals versus patients with cubital tunnel syndrome. RESULTS During the study period, 168 patients underwent decompression of the ulnar nerve for cubital tunnel syndrome, and an anconeus epitrochlearis was found at surgery in 9 (5.4%) patients. The control group consisted of 634 asymptomatic patients from the medical literature, and an anconeus epitrochlearis was present in 98 (15.5%) of these patients. An anconeus epitrochlearis was present significantly less frequently in the symptomatic patients than in asymptomatic individuals (p < 0.001). Among patients undergoing surgical decompression, an anconeus epitrochlearis was associated with symptoms in the dominant arm (p = 0.037). CONCLUSIONS The authors found that an anconeus epitrochlearis was present significantly less often in patients with cubital tunnel syndrome than in asymptomatic controls. The mechanism of protection may be that this muscle decreases the rigidity of the entrance into the cubital tunnel. When an anconeus epitrochlearis does contribute to cubital tunnel syndrome, it is significantly more likely to occur in the dominant arm, possibly due to repetitive use and hypertrophy of the anconeus epitrochlearis. The presence of an anconeus epitrochlearis may be protective against the development of cubital tunnel syndrome, although this is a preliminary finding.

Comparative anatomy of the gluteal muscles of Sapajus libidinosus 1

ABSTRACT: New World primates Sapajus sp. unexpectedly display cognitive aspects, tool use, social behavior, memory and anatomical aspects similar to Old World primates, such as chimpanzees and baboons. Convergent evolutionary aspects must have occurred between Sapajus and Old World primates and should be verified not only in terms of behavior analysis, but also of anatomical structure. The pelvic region can provide data for evolutionary verification trends, since taking standing position is one of the characteristics associated to the use of tools by early humans and pongids. We used eight specimens of Sapajus libidinosus to describe the deep muscular structure of the pelvis. Unlike humans, the gluteus medius muscle in S. libidinosus is completely covered by the gluteus maximus and elongated as compared to humans and chimpanzees, putatively by the elongated pelvis of S. libidinosus. Considering origin and insertion, the gluteus maximus muscle resembles more its counterpart in baboons than in humans and chimpanzees, since this muscle in baboons is associated to semibiped posture and to the tail. Gluteus minimum, piriformis, superior gemellus, internal shutter, gemellus and lower square muscles are positioned in this order in relation to the cranial-caudal axis, with all of its tendons converging for a common insertion in the greater trochanter. The muscles of the gluteal region of S. libidinosus are similar to the baboon, especially regarding the gluteus maximus, which points to the evolutionary kinship of these animals.