Undergraduate Dissection Research Articles

A Cadaveric Study on Radial Nerve Risk Zone in the Distal Part of the Arm

Introduction: Injury to the radial nerve in the arm is very frequent following fractures of the shaft of the humerus and may also occur during surgery on the arm. These iatrogenic injuries can be prevented by predicting the point at which the nerve penetrates the lateral intermuscular septum during its course from the posterior-to-anterior compartment of the arm. Aims and Objectives: Our study aims to find out the point of penetration of the radial nerve in the lateral intermuscular septum (radial nerve risk zone [RNRZ]). Materials and Methods: The study was conducted on 30 upper limbs of adult formalin-embalmed cadavers during MBBS undergraduate dissection at the department of anatomy. The posterior aspect of the arm was dissected to expose the radial nerve, and measurements of parameters were recorded. Results: The mean humeral length was 29.91 ± 2.66 cm. The mean distance from the lateral epicondyle of the humerus to the point on the lateral intermuscular septum where radial nerve pierces during its course from posterior-to-anterior compartment was 11.42 ± 1.042 cm, r = 0.368, and P < 0.05 which was statistically significant. The mean (standard deviation) humeral length of both left and right side difference was statistically significant with P = 0.009 (P < 0.05). Conclusion: We believe that our study will help orthopedic surgeons to estimate the point of penetration of radial nerve into the lateral intermuscular septum which is the RNRZ. This minimizes the risk of radial nerve damage during the fixation of the fractured shaft of the humerus.

Neural and Arterial Variations in the Right Upper Limb of a Single Cadaver- A Case Report

Background: During routine undergraduate dissection of a 43 years old male cadaver some important neural and arterial anatomic variations were seen in a single right upper limb in the form of double medial roots of median nerve and superficial brachial artery. Observation: During routine dissection of a 43-year-old male cadaver, some important neural and arterial anatomical variations were observed in a single right upper limb in the form of double medial roots of the median nerve and superficial brachial artery. The median nerve was formed in axilla by the union of one lateral and two medial roots on lateral side of axillary artery. The brachial artery which crossed the median nerve superficially from the medial to the lateral side, in the middle of the arm, continued as the superficial brachial artery. The variations were observed and photographed. Conclusion: The knowledge of such variations is however not only desirable, but also essential as these have important influences on the predisposition to illness, clinical examination, investigations and patient management, including operative surgery.

The value of in-person undergraduate dissection in anatomical education in the time of Covid-19.

While several innovative pedagogical practices have been developed and implemented in anatomy education since the onset of the coronavirus disease 2019 (Covid‐19) pandemic, considering the value of in‐person undergraduate dissection remains crucial. In this commentary, a human dissection course at the University of Toronto is used as an example to highlight the value of dissection for undergraduate learners in non‐professional programs. In‐person dissection allows for real life, anatomical variation, and supports the advancement of students' conceptual knowledge of the human body and visual–spatial abilities. Direct involvement with dissection during undergraduate training also provides students with an opportunity to practice and refine non‐technical skills, such as communication and collaboration, while simultaneously promoting the development of students' professional identity formation. Further, dissection is a practical, hands‐on experience that can provide students with insight into potential career aspirations related to anatomy and the health professions. It is suggested that as institutions veer from traditional pedagogical practices and evaluate how to best move forward post‐pandemic, it is imperative that the value of undergraduate dissection is considered among new innovations in the field of anatomy.

Brachial plexus variations in the flexor compartment of arm with its clinical implications and embryological basis: A cadaveric study

BackgroundThe nerve supply of the upper limb, which is provided by the brachial plexus, is extremely important from a medical and surgical perspective. Muscles of the flexor compartment of the arm are destined to have their nerve supply from the musculocutaneous nerve, a branch from the lateral cord of the brachial plexus. Variations in the formation and branching of the brachial plexus are not uncommon. These variations have clinical significance during surgical procedures, in the brachial plexus block, and in diagnostic clinical neurophysiology. Material & methodsThe study was carried out in the department of anatomy consisting of 56 limbs during routine undergraduate dissection classes. Dissection of the infraclavicular part of the brachial plexus was done. The variations in the origin, number, and distribution of the branches derived from the cords to the flexor compartment of the arm and their correlations to the coracobrachialis were noted. Observation & results47 limbs (83.92%) showed a normal morphological pattern of formation and distribution of brachial plexus to the flexor compartment of the arm. 9 limbs (16.07%) showed variations in one form or the other. Two limbs (3.57%) showed an absence of musculocutaneous nerve (MCN). In 3 limbs (5.35%) coracobrachialis was not being supplied by MCN, and 4 limbs (7.14%) exhibited a communication between MCN and Median Nerve (MN). ConclusionVariations in the nerves supplying the flexor compartment of the arm have clinical implications in post-traumatic evaluations and exploratory innervations of the arm for peripheral nerve restoration. It is important for surgeons, clinicians, and anatomists to be aware of these possible anatomical variations to avoid unexpected complications.

Study of variations in the formation and branching pattern of lateral cord of brachial plexus- A detailed cadaveric study

As the formation of brachial plexus involves numerous nerve roots, it is more common than rare to find variations in the formation and its branching pattern. Innumerable variations in the formation of lateral cord of brachial plexus and the branches of the lateral cord of brachial plexus are reported. This study is done with an intension to specifically look into the possible variations in the formation and branches of the lateral cord of brachial plexus only. The present study was carried on cadavers during undergraduate dissection, in the Department of Anatomy, Velammal Medical College, Annupanadi, Madurai, Tamilnadu India. In the present study The cadavers were dissected out to find the branching pattern of the Lateral cord and the observations were analysed, many variations in the branching patterns were observed, significant one being the musculocutaneous nerve being absent, coracobrachialis being supplied by branch from lateral root of median nerve, in another musculocutaneous nerve ends by supplying only coracobrachialis and the rest are supplied by the branches from median nerve. The frequency of anomalies found in the arrangement and distribution of lateral cord and its branches makes this anatomic region complicated with regard to surgical approaches.

Morphometric Study of Cadaveric Spleen in Vidarbha Region

Background: Spleen is one of the largest lymphoid organs that are involved in haemopoitic function also during fetal life. Its anatomy is useful not only for Anatomist but also for Surgeons, Radiologists and Physicians. A lot of variations are observed in the spleen from its shape to size which is important to diagnose or treat the number of diseases.
 Methodology: This study was carried out on 60 spleens in the dissection hall of our medical college which were removed during routine undergraduate dissection. The parameters studies were shape of the spleen, number of notches (single or multiple), location of notches (Superior or inferior border), weight, breadth, width or length.
 Results: The 90% spleens has single notch. The weight of the spleens ranges from 89 gm to 220 gm with an average 142.6 gm. Range of breadth observed 3.5cm to7.4cm with an average 5.8cm, Range of width observed 2.8cm to 5.7cm with an average 4.1cm. Range of length observed 8.1cm to13.2cm with an average 11.7cm.
 Conclusion: Morphological variation is very common in spleen and varies according to the genetic, geographic, nutrition and work habits of individual and varies regions to regions of India. Morphological analysis is under reported and need to be carry out at different regions and places for obtaining more accurate data.

STUDY OF VARIATIONS OF CERVICAL SEGMENT OF INTERNAL CAROTID ARTERY

Introduction: Presence of variations in the course of the cervical (extracranial) part of the internal carotid artery (I.C.A.) in the form of tortuosity, kinking, coiling or looping is a rare condition. These may be attributed to embryological or acquired factors. Patients with such variations may be asymptomatic in some cases, whereas, they may develop cerebrovascular symptoms due to carotid stenosis affecting cerebral circulation. Materials and methods: The present study was performed during routine undergraduate dissection classes in total 21 human cadavers (6 females and 15 males) on bilateral sides. Results: Bilateral kinking and looping of the cervical part of the I.C.A. was found in two cadavers. Conclusions: The risk of transient ischemic attacks (TIA) in patients with carotid stenosis is high and surgical correction is indicated as a part of treatment. Further, patients having these variations are more prone to injury during radical neck dissection and other surgical operations of the neck region. Knowledge about anatomy of such variations provides a framework to review the embryogenesis of the structure and also provides insight into surgical, medical and radiological implications.

Variations in the Axillary Artery Branching Pattern

Variations in axillary artery branching pattern can lead to iatrogenic injuries during invasive procedures. Knowledge of the same is critical to prevent such events. Multiple bilateral variations were observed in the branching pattern of axillary artery. These variations were noted in a female cadaver, during routine undergraduate dissection in September 2019 in Lady Hardinge Medical College, New Delhi. On the left side, an anomalous branch running with the medial pectoral nerve was found. A common stem arising from the 2nd part of left axillary artery divided to give the lateral thoracic artery, the subscapular artery and an alar artery. Another alar branch arose from the left subscapular artery before it bifurcated into thoraco-dorsal and circumflex scapular arteries. The right axillary artery gave an aberrant branch proximal to the lateral thoracic artery. A common trunk arising from the 2nd part of right axillary branched out to give the posterior circumflex humeral artery, the subscapular artery and an alar artery. The brachial artery divided 13.5 cm proximal to the intercondylar line of humerus on the left and 14.4 cm on the right side. On both sides, the ulnar artery arose proximally and the radial and common inter-osseous arteries continued as a common trunk and divided distally. This case study reports multiple bilateral axillary artery anomalies and complements to the existing knowledge of vascular anomalies. Comprehensive knowledge of these variations is essential from anatomical, radiological and surgical point of view. During surgeries involving axillary and pectoral group of lymph nodes, such variations should be kept in mind.

The Impact of a Novel Computer‐assisted Learning Resource on Student Learning in Undergraduate Dissection‐ and Prosection‐based Laboratory Environments

Human anatomy is an essential subject for the medical and health sciences. Teaching and learning human anatomy each require large investments of time and resources; however, many institutions are challenged by limitations to both. As a result, the approaches used to teach human anatomy are constantly evolving to overcome these limitations and deliver meaningful learning opportunities. One common method for enhancing anatomy education is through computer‐assisted learning (CAL). The rapid growth and advancement of technology over recent decades has made the creation of CAL resources cheaper, easier, and more accessible, facilitating their rise as popular supplements to traditional approaches such as dissection (DI) and prosection (PRO). Accordingly, this study evaluated a novel CAL resource that was created for and introduced into an undergraduate DI and PRO human anatomy course at the University of Guelph between the Fall 2015 and 2016 semesters. The objective was to determine the influence of the resource on the students' academic experiences through evaluations of their course satisfaction (CS), contextual approaches to learning (SAL, characterized by deep [DA] and surface [SA] approach scores), and overall course performance.Participants reported their demographic information, CS, SAL, and use of the CAL resource through a combination of online and written surveys. Written feedback regarding their perceptions of the CAL resource was also collected and thematic analysis was performed to extract common themes. CS was compared between the Fall 2015 and Fall 2016 academic cohorts using the Mann‐Whitney U test. Comparisons of contextual SAL and performance were made using analyses of covariance with preferred SAL scores and cumulative grade averages as covariates, respectively. CAL resource use by students in both DI and PRO was then characterized and multiple linear regression analyses were used to determine correlations between their use of the resource and DA scores, SA scores, and course performance.Although the students' mean (± SEM) CS improved between the 2015 and 2016 cohorts in both DI (2015 = 74.15 ± 3.29, 2016 = 86.54 ± 1.94, p = 0.002) and PRO (2015 = 78.41 ± 5.95, 2016 = 93.55 ± 3.06, p = 0.051), the mean differences (± SEM) in DA (DI = −2.11 ± 0.53, p < 0.0005; PRO = −2.72 ± 1.03, p = 0.010) and SA (DI = 1.95 ± 0.55, p < 0.0005; PRO = 4.16 ± 1.10, p < 0.0005) scores suggested that the course presented a more surface‐oriented environment in 2016 than in 2015. Contextual SAL and course performance were not directly influenced by CAL resource use (p > 0.05); however, students in both DI (p = 0.001) and PRO (p = 0.025) who reported higher positive perceptions of the resource had higher DA scores.These findings indicated that using the CAL resource did not significantly enhance the students' learning experience. However, those who saw value in the resource and reported more positive perceptions toward it used deeper approaches to learning, which are representative of meaningful learning. Alongside the analyses of written student feedback, this suggests that the context in which CAL resources are to be disseminated may merit strong consideration before incorporating such resources into a course.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

An unusual branching pattern of the axillary artery

Variations in the branching pattern of axillary artery are frequently found. Knowledge about the variations in the branching pattern of Axillary artery is important for surgeons to avoid intraoperative injuries in axilla. An unusual unilateral variation in branching pattern of axillary artery was found during routine undergraduate dissection in Medical College & Hospital, Kolkata. Variation consist of origin of a common arterial trunk from the 2nd part of axillary artery which was giving rise to 4 branches namely, Anterior & Posterior circumflex humeral artery, Arteria profunda brachii and superior ulnar collateral artery, rest of the branches were as usual.

Left-Sided Persistent Superior Vena Cava with Superior Hemiazygos Arch

Persistent Left-side Superior Vena Cava (PLSVC) is the congenital central venous anomaly draining into the right atrium in 82-90% of cases via coronary sinus produce no haemodynamically significant consequences. In few cases it may drain into the left atrium directly or through the pulmonary veins resulting in right to left shunt. During routine undergraduate dissection, we found a PLSVC formed by the union of left subclavian and left internal jugular veins behind the left sternoclavicular joint was terminated into the right atrium through a larger coronary sinus ostium. Before its termination, PLSVC received a left hemiazygos vein formed by the continuation of the superior and inferior hemiazygos veins. A larger but thin communicating vein was noted between the right superior vena cava and PLSVC. Prior knowledge about such variations is essential in all the intervention procedures on right atrium through the left subclavian approach and also like in our case, the larger coronary sinus ostium if found during transthoracic echocardiography should be considered as an indication for the diagnosis of PLSVC.

ONTOGENY RECAPITULATES PHYLOGENY: COMMUNICATION BETWEEN THE MEDIAN AND THE MUSCULOCUTANEOUS NERVE: A CASE REPORT

Neural variations of the brachium constitute important anatomical and clinical entity.Abnormal variations of median nerve, musculocutaneous nerve and their communicating branches have been reported very frequently by the anatomists in the past. The nerves of the extremities are particularly vulnerable to injury because of their long course and superficial distribution. Present report describes a case of a single abnormal communication between median and musculocutaneous nerve encountered in a 55 year old Indian male cadaver during routine undergraduate dissection. Knowledge of such anatomical variations is important while planning surgery in the region of axilla or arm as these nerves are more liable to be injured during surgical procedures as well as may result in unusual entrapment neuropathies. Clinical significance of such type of variation in the light of its developmental origin has been discussed.

MULTIPLE MORPHOLOGICAL VARIATIONS IN THE THYROID GLAND: REPORT OF TWO CASES

The variety of multiple morphological variations in the thyroid gland is found as a result of disturbed organogenesis in humans as agenesis, hypoplasia, accessory, ectopy and hemiagenesis. In the routine undergraduate dissection of the thyroid gland, multiple anomalies of the thyroid gland were encountered in 50 and 60 years old female and male cadaver respectively. These were in form of absent isthmus with accessory thyroid lobe in between two lateral lobes, pyramidal lobe arising from left lobe of thyroid with levator glandulae thyroidae in first case. Second case showed narrow isthmus related to first tracheal ring and levator glandulae thyroidae arising from left lobe. In these case studies, we highlight various developmental anomalies of the thyroid gland as absent isthmus, pyramidal lobe and accessory lobe with levator glandulae thyroidae. Hence a thorough knowledge of such morphological variations of thyroid gland helps the surgeons in better planning of safe, effective and uncomplicated operative procedures in resection of thyroid and tracheotomy procedures.

English

CONTEXT: Variations in the peritoneal reflections of the gallbladder are encountered during surgery and post-mortem examinations mainly form of mesentery and often have significant clinical implications, which can be life threatening at times. AIM: In this study, the manner of the peritoneal reflection over the gall bladder, its relative adherence to the gall bladder fossa and the relation of the fundus to the inferior margin of liver was examined. SETTINGS AND DESIGN: This cadaveric gross anatomical study was undertaken in the Department of Anatomy, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra, India and Subharti Medical College, Meerut, Uttar Pradesh, India, in the course a four year period i.e. 2008 to 2012, after obtaining necessary permission from the Institutional Ethical Committees. METHODS AND MATERIAL: It was carried out on one hundred gall bladders specimens, obtained from 10% formalin fixed cadavers during routine undergraduate students dissection The liver along with the gall bladder was retrieved from the abdominal cavity during undergraduate dissection of the abdomen and the peritoneal reflection over it was studied. RESULTS: Differential peritoneal reflections were observed in seven out of hundred specimens and formation of mesentery over the whole organ was found in two. In two there was mesentery over the neck and upper part of body. One the gall bladder was found floating in the gall bladder fossa but without the formation of mesentery. CONCLUSIONS: Differential peritoneal reflections of gall bladder were seen in seven specimens and mesentery formation to various degrees was seen in four. It was observed that peritoneal attachment of the gall bladder and the relative adherences of the viscus to the gall bladder fossa were closely associated.

Implications of Anatomical and Morphological Variations of Thyroid Gland: A Case Report

Because of extreme variations in gross Anatomy of Thyroid Gland, Marshal stated that it was a difficult work to speak about normal thyroid gland [1]. Description of incidence of Pyramidal lobe, an embryological remnant of thyroglossal duct differ from 15 to 75% in Anatomical text books and data concerning its size are lacking [2, 3]. During the routine undergraduate dissection of Thyroid gland for Ist year MBBS in the Department of Anatomy, Govt. Medical college, Amritsar, India, in an elderly Male cadaver various morphological anomalies of Thyroid gland were encountered. These were in the form of presence of pyramidal lobe on left side, tip of which was attached to hyoid bone through Levator glandulae thyroidae and absence of superior thyroid artery on right side. The knowledge of various Anatomical & Morphological variation will help surgeons in forming a cornerstone to safe and effective surgeries.

Lingual lobe of right lung- a rare variation

Knowledge of variations of lobar pattern of lung is important for identification of bronchopulmonary segments. It is of great clinical significance for surgeons and radiologists. Normally the right lung has two fissures, one oblique and one horizontal and three lobes, upper, middle and lower lobes. Many authors have described the lobar variations on imaging techniques but a few studies have reported in gross anatomy. The present case highlights an abnormal lingual lobe of the right lung which was detected incidentally during the undergraduate dissection. Also it highlights the abnormal pattern of oblique and horizontal fissures.

Variation of hilar anatomy in an incompletely rotated kidney associated with accessory renal vessels

An incompletely rotated left kidney, with variations in the hilar anatomy associated with accessory renal vessels was seen during routine undergraduate dissection in an adult male cadaver. The left kidney showed three accessory renal vessels. Two renal arteries and one vein entered the lower pole of left kidney. The hilum of the kidney was anteriorly faced and was close to the upper pole, with the ureter running on the anterior surface of the kidney. This was associated with variation in the arrangement of the structures at the hilum. Structures found at the hilum from superficial to deep were: The ureter, one renal vein, and two renal arteries. The ureter was anteroinferior and lateral to the renal vein. The renal arteries were posterosuperior and posteroinferior to the renal vein. The rotational anomaly associated with the presence of accessory renal vessels assumes importance while performing percutaneous procedures in relation to the kidney, screening of donors, and also during interpretation of various radiological diagnostic procedures related to the kidney.

A Rare Anomaly of Vertebral Artery – a case report

During routine undergraduate dissection we have found a rare origin of left vertebral artery that is arising from superior aspect of arch of aorta in between left common carotid artery and left subclavian artery.Right vertebral artery having a normal origin from 1 st part of subclavian artery.This topic is very helpful to various speciality persons like neurosurgeons, vascular surgeons, ent surgeons.

Bilateral variant of sciatic nerve exhibiting intra-pelvic division

Context (background): In case of high division of the sciatic nerve in the pelvis its, common peroneal component may pierce the Piriformis muscle. This anatomical variant can explain many clinical findings. Aims: Its objective is to report a case of high division of the sciatic nerve in order to contribute towards better anatomical understanding of the gluteal region. Methods and Material: Routine undergraduate dissection of a male cadaver revealed bilateral variation in sciatic nerve. Results: Sciatic nerve is dividing into tibial and common peroneal components in the pelvis. Common peroneal component is piercing through the piriformis muscle. Tibial component is emerging between piriformis and superior gemelli muscle. Conclusions: Sciatic nerve variation can lead to a Piriformis muscle syndrome, inadvertent injury during operations in the gluteal region, failure of sciatic nerve block and/or sciatic neuropathy. The differences in routes of these two nerve components can explain them.

Multiple anomalies in abdominal vasculature-a case report

During a routine undergraduate dissection of the abdomen of a 50-year-old male cadaver, multiple anomalies of vasculature were seen, viz. retro-aortic left renal vein, left suprarenal vein draining into the inferior vena cava instead of left renal vein, tortuosity of two common iliac arteries, early division of right renal artery into segmental branches near its origin from aorta, right segmental renal arteries entering right kidney anterior to right renal vein and right accessory renal artery. Such multiple vascular anomalies occurring concurrently in the same person are extremely rare and may pose danger to his life if the surgeon operating on him is not aware of these. Ontogeny and clinical implications of all these variations are discussed in detail.