Anatomical Study Research Articles

Morphological classification, anatomical variations, innervation patterns, musculocutaneous nerve relation of the coracobrachialis muscle: Anatomical study and clinical significance.

The anatomical variations of coracobrachialis muscle (CBM) are of great clinical importance. This study aimed to elucidate the morphological variations, innervation patterns and musculocutaneous nerve (MCN) relation to CBM. Upper limbs of fifty cadavers (30 males and 20 females) were examined for proximal and distal attachments, innervation pattern of CBM and its relation to MCN. Four morphological types of CBM were identified according to number of its heads. The commonest type was the two-headed (63.0%) followed by the single belly (22.0%), three-headed (12.0%) and lastly four-headed (3.0%) type. Moreover, an abnormal insertion of CBM was observed in four left limbs (4.0%); one inserting into the medial humeral epicondyle, the second into the upper third of humeral shaft, the third one in the common tendon of biceps, and the fourth one showing a bifurcated insertion. Also, four different innervation patterns of CBM were identified including MCN (80.0%), lateral cord (14.0%), lateral root of median nerve (4.0%), and median nerve itself (2.0%). The course of MCN was superficial to the single belly CBM (19.0%) and in-between the heads in the other types (71.0%). Measurements of the length and original distance of CBM muscular branches originating from MCN revealed no sex or side significant difference. Awareness of the anatomic variations, innervation patterns, and MCN relation of CBM is imperative in recent diagnostic and surgical procedures to obtain definite diagnosis, effective management and good outcome.

Chordae Willisii of the dural sinuses: an anatomical study using magnetic resonance imaging.

The chordae Willisii (CWs), trabecular projections into the lumen of the dural sinuses, are not well understood. We aimed to explore them using magnetic resonance imaging (MRI). Eighty-five patients underwent volumetric contrast-enhanced MRI, while another 30 underwent a fluid-attenuated inversion recovery (FLAIR) sequence in the coronal section. The CWs were detected as linear filling defects lying in the dural sinuses, adjacent to the surrounding dura mater. They were found in the superior sagittal sinus (SSS) in 68.2% of the patients, most frequently in the middle third, with laminar appearance. In 27.1% of the patients, the CWs divided the SSS lumen into separate channels. The CWs were identified in the transverse sinus, transverse-sigmoid sinus junctional area and sigmoid sinus, and straight sinus in 54.1, 47.1, and 8.2%, respectively. On the FLAIR images, dural septi partially dividing the SSS lumen were identified in all patients. In addition, in 73.3% of the patients, fine linear structures were observed in the lumen with inconstant arrangements. The CWs may be constant structures distributed over the lumen of the intracranial dural sinuses. Contrast-enhanced MRI may be useful for detecting laminar CWs. The FLAIR sequence may be advantageous for delineating the dural septi projecting into the lumen of the dural sinuses.

Anatomy of the clitoris: the corona of the glans clitoris, clitoral coronal papillae, and the coronopreputial frenulum.

The corona of the glans clitoris is a clinically important yet poorly understood anatomical structure. There has been longstanding confusion regarding the prevalence of the corona of the glans clitoris and, moreover, its very existence. Therefore, this anatomical study assesses the prevalence of the corona of the glans clitoris and the gross anatomy of the proximal glans clitoris. Anatomy was assessed in 104 female donor bodies ranging in age from 50 to 102 years with an average age-at-death of 78.1±10.9 years (mean±SD). All clitorises (100%; 104:104 dorsums and 100%; 208:208 sides) were found to have a well-defined clitoral corona. Three of 104 (2.9%) coronas possessed grossly visible, outward-projecting, bluntly rounded papillae. Some donors possessed a coronopreputial frenulum. Clitoropreputial adhesions were common and associated with clitoral pearls. Clitoral pearls were identified in 37.8% (14:37) of unembalmed donors and observed to create clitoral craters, structural deformations in the surface of the corona and glans. The results of this study suggest that the corona of the glans clitoris is a ubiquitous anatomical structure. The clitoral coronal papillae and coronopreputial frenulum are novel, previously undescribed, anatomical structures. This study identifies that the corona of the glans clitoris is prone to pathological processes such as clitoral pearl formation and clitoral deformation. In addition to novel anatomical findings, the results of this study call attention to the need for life-long clitoral examinations. Furthermore, the corona of the glans clitoris should be regularly included in anatomical texts and accurately depicted in anatomical illustrations.

Anatomical study of the relationship between the lumbar intervertebral disc, nerves, and psoas major.

Cadaveric study; To describe the characteristics of the nerve and its relationship with the lumbar intervertebral disc and psoas major muscle. Nerve injury is an understudied complication of extreme lateral interbody fusion. A detailed description of the nerve anatomy would be helpful for surgeons to minimize the risk of this complication. The lumbar plexus and lumbar sympathetic nerve of 10 embalmed male cadavers were dissected, and the distribution, number, and spatial orientation of the nerves on the L1/2 to L4/5 intervertebral discs were examined. Metal wires were applied along nerve paths through the psoas major muscle. The position of the nerves was examined on CT. In zone III at L1/2 and L4/5, no nerves were found. In zone II and zone III at L2/3, no lumbar plexus was found, and only the ramus communicans passed through. At the L1-L5 level, the density of nerves in the posterior half of the psoas major muscle was greater than that in the anterior half. The lumbar plexus was found in all of zone IV. The genitofemoral nerve emerges superficially and anteriorly from the medial border of the psoas major at the L3-4 level, but at the L1/2 level, the sympathetic trunk is located in zone II. The remaining disc-level sympathetic trunks appear in zone I. No nerves were found in zone III of the L1/2 or L4/5 disc. In zones II and III of L2/3, the lumbar plexus appears safe. The genitofemoral nerve travels through zones II and III of L3/4. The distribution density of nerves in the posterior half of the psoas major muscle was greater than that in the anterior half of that muscle at the L1-L5 level.

Anatomic Study of Vascular Supply of the External Ear Using CT Angiography in Congenital Microtia

Background: The morphology of the arteries of the external ear on the affected side of congenital microtia differs from normal. The present study aimed to use computed tomography angiography (CTA) to describe the anatomic variations of arteries in microtia and provide theoretical guidance for the first stage of autologous auricular reconstruction by the 2-stage method. Methods: Ten patients with unilateral microtia from May 2021 to August 2021 were included. Computed tomography angiography and 3-dimensional reconstruction were used to analyze the supply and branches of the main arteries of the auricle. The number of the superficial temporal artery (STA) and posterior auricular artery (PAA) branches to the auricle, vessel diameter, and the presence or absence of the STA and PAA branches were documented. The skin flap and incision were designed combined with the anatomic of auricular arteries. Results: The blood supply of the auricle mainly came from the STA and PAA. The STA’s preauricular branch and PAA’s posterior auricular branch were absent to varying degrees, and the middle branch was more prominent. The average diameter of the STA on the healthy auricle was 3.07±0.96 mm, and the average diameter of the PAA was 1.72±0.50 mm. The average diameter of the STA on the microtia auricle was 2.65±0.42 mm, and the average diameter of the PAA was 1.53±0.67 mm. There was a statistically significant difference in the diameter of STA between the healthy auricle and the microtia auricle (P=0.006). However, there was no significant difference in the diameter of the PAA between the healthy auricle and the microtia auricle (P=0.112). The skin flap and incision were designed and combined with the preoperative CTA images, and no flap necrosis was observed in all patients. Conclusion: The vascular distribution of arteries in microtia patients was clearly and accurately assessed by CTA. In our experience, the data and detailed imaging were useful in designing skin flaps and incisions during the first stage of autologous auricular reconstruction by the 2-stage method.

Human shoulder anatomy: new ultrasound, anatomical, and microscopic perspectives.

This study aimed to describe the shoulder anatomy, together with the anatomical relationships in adults and early stages of development. The shoulder muscles were studied from ultrasound, anatomical, and microscopic perspectives in a sample of 34 human shoulders. Thickness measurements were taken of the tendons and fasciae of the subscapularis, long head tendon of the biceps brachii, supraspinatus, infraspinatus, and teres minor. Ultrasound and dissection techniques are strongly correlated. However, the measurements obtained from the dissection technique were superior to those obtained from the ultrasound in all cases, except for the thickness of the long head tendon of the biceps brachii, the teres minor tendon, and the fascia thickness of the infraspinatus. In addition, the study of shoulder anatomy revealed no differences between females and males. Relevant findings from dissection included a clear overlap between the infraspinatus and supraspinatus, which shared tendon fibers, and a similar connection between the transverse ligament of the long head tendon of the biceps brachii and the subscapularis, which created a more interconnected shoulder function. The study of the anatomical measurements shows an underestimation of the shoulder measurements in the ultrasound compared with the dissection technique, but a high correlation between the measurements made by the two techniques. We present reference values for the tendon and fascia thicknesses of the rotator cuff, with no differences observed by gender. The relationships between shoulder structures described in the anatomical study imply as well that, in the event of an injury, adjacent tissues may be affected. This extended information may facilitate future optimal clinical explorations.

Surgical anatomical landmarks for arthroscopic repair of subscapularis tendon tears

Background: Subscapularis repair has recently garnered significant interest. A thorough understanding of the tendon’s anatomy is essential for precise and safe repair. Our objectives were to describe the anatomy of the subscapularis insertion, define its landmarks, and analyze nearby structures to guide arthroscopic repair.Methods: We conducted an anatomical study, dissecting 12 shoulders. We evaluated the distance from the footprint to the axillary nerve, the dimensions, and shape of the footprint, and its relationship with the humeral cartilage.Results: The distance to the axillary nerve was 32 mm (standard deviation [SD], 3.7 mm). The craniocaudal length of the footprint was 37.3 mm (SD, 4.6 mm). Its largest mediolateral thickness was 16 mm (SD, 2.2 mm), wider at the top and narrower distally. The distance between the footprint and the cartilage varied, being 3.2 mm (SD, 1.2 mm) in the upper part, 5.4 mm (SD, 1.8 mm) in the medium, and 15.9 mm (SD, 2.9 mm) in the lower part.Conclusions: When performing a repair of the subscapularis tendon, the distance to the cartilage should be carefully evaluated as it varies proximally to distally, and the shape of the footprint (wider proximally, tapered distally) should be considered for implant positioning. The distance to the axillary nerve is approximately 30 mm. Anterior visualization guarantees direct control of all landmarks and allows accurate implant positioning with safe tendon release.

MORPHO-ANATOMICAL PROFILE OF ELAEOCARPUS TUBERCULATUS ROXB

Objective: The anatomical studies of Elaeocarpus tuberculatus Roxb. (Elaeocarpaceae), an indigenous medicinal plant in the Indian pharmacopoeia. Methods: Fresh leaf and stem samples of E. tuberculatus were scrutinized macroscopic and microscopically by standard procedures. Results: Macroscopically, the leaves are simple, long, coriaceous, and rusty below, base obtuse, margin serrate, apex obtuse and petiole 3 cm long. Microscopically, the leaf showed the presence of four prominent collateral bundles. Paracytic stomata were distributed in the abaxial epidermis whereas the adaxial epidermis was apostomatic. The petiole was four-angled including wing bundles. The stem exhibited fissured periderm, wide secondary phloem, secondary xylem with incipient growth ring and abundant calcium oxalate crystals. Powdered microscopic study of the leaf revealed the presence of long whip-like epidermal trichomes, crystals, vessel elements showing pits and fiber-like sclereids. The stem powder showed thick-walled fibers with wide lumen, narrow fibers and a sclerenchyma cell showing wide pits. Conclusion: The results of the study can serve as a valuable source of information and provide suitable standards for the identification of E. tuberculatus in future investigations and applications

Combined Endoscopic Endonasal Transclival and Contralateral Transmaxillary Approach to the Petrous Apex and the Petroclival Synchondrosis: Working "Around the Corner" of the Internal Carotid Artery-Quantitative Anatomical Study and Clinical Applications.

The endoscopic contralateral transmaxillary (CTM) approach has been proposed as a potential route to widen the corridor posterolateral to the internal carotid artery (ICA). In this study, we first refined the surgical technique of a combined multiportal endoscopic endonasal transclival (EETC) and CTM approach to the petrous apex (PA) and petroclival synchondrosis (PCS) in the dissection laboratory, and then validated its applications in a preliminary surgical series. The combined EETC and CTM approach was performed on three cadaver specimens based on four surgical steps: (1) the nasal, (2) the clival, (3) the maxillary and (4) the petrosal phases. The CTM provided a "head-on trajectory" to the PA and PCS and a short distance to the surgical field considerably furthering surgical maneuverability. The best operative set-up was achieved by introducing angled optics via the endonasal route and operative instruments via the transmaxillary corridor exploiting the advantages of a non-coaxial multiportal surgery. Clinical applications of the combined EETC and CTM approach were reported in three cases, a clival chordoma and two giant pituitary adenomas. The present translational study explores the safety and feasibility of a combined multiportal EETC and CTM approach to access the petroclival region though different corridors.

Modulation of contextual fear acquisition and extinction by acute and chronic relaxin-3 receptor (RXFP3) activation in the rat retrosplenial cortex

The retrosplenial cortex (RSC) plays a central role in processing contextual fear conditioning. In addition to corticocortical and thalamocortical projections, the RSC receives subcortical inputs, including a substantial projection from the nucleus incertus in the pontine tegmentum. This GABAergic projection contains the neuropeptide, relaxin-3 (RLN3), which inhibits target neurons via its Gi/o-protein-coupled receptor, RXFP3. To assess this peptidergic system role in contextual fear conditioning, we bilaterally injected the RSC of adult rats with an adeno-associated-virus (AAV), expressing the chimeric RXFP3 agonist R3/I5 or a control AAV, and subjected them to contextual fear conditioning. The R3/I5 injected rats did not display any major differences to control-injected and naïve rats but displayed a significantly delayed extinction. Subsequently, we employed acute bilateral injections of the specific RXFP3 agonist peptide, RXFP3-Analogue 2 (A2), into RSC. While the administration of A2 before each extinction trial had no impact on the extinction process, treatment with A2 before each acquisition trial resulted in delayed extinction. In related anatomical studies, we detected an enrichment of RLN3-immunoreactive nerve fibers in deep layers of the RSC, and a higher level of co-localization of RXFP3 mRNA with vesicular GABA transporter (vGAT) mRNA than with vesicular glutamate transporter-1 (vGLUT1) mRNA across the RSC, consistent with an effect of RLN3/RXFP3 signalling on the intrinsic, inhibitory circuits within the RSC. These findings suggest that contextual conditioning processes in the RSC involve, in part, RLN3 afferent modulation of local inhibitory neurons that provides a stronger memory acquisition which, in turn, retards the extinction process.

The mylohyoid line is highly variable but does not affect the microarchitecture of the edentulous alveolar bone – an anatomical micro-CT study

ObjectivesTo evaluate in the absence of teeth the variability of the mylohyoid line (ML), the microarchitecture of the adjacent bone, and whether the variable prominence/width of the ML is associated with the quality of the adjacent bone.MethodsµCT scans of 28 human mandibles from anatomical specimens were analyzed. The following parameters were assessed in four edentulous areas (first and second premolar (PM), first, second, and third molar (M1/2/3)): ML width, cortical thickness (CtTh), average cortical- (Avg.Ct.BV/TV), and trabecular bone volume fraction (Avg.Tb.BV/TV).ResultsThe ML width increased from the PM towards the M2 region, which also showed the highest variance (range: 0.4–10.2 mm). The CtTh showed a decrease in the M3 region, while Avg.Ct.BV/TV and Avg.Tb.BV/TV hardly differed among the regions. In the multivariable model on the effect of the various parameters on the ML width, only gender and tooth region were significant. Specifically, male specimens were associated with a wider ML width compared to female specimens and the M2 region was associated with a wider ML width compared to the other tooth regions.ConclusionThe ML width was not associated with the cortical and trabecular bone quality in the adjacent bone, while gender and tooth region had a significant effect. Specifically, the ML width was lower in female, but peaked in the M2 region with a median width of 3–4 mm.Clinical relevanceFrom a clinical point of view, it was confirmed that the ML is in general a highly variable structure, especially in the M2 region, but the ML width does not allow any conclusions on the bone quality. Altogether, this underlines the need for an individual and accurate diagnostic prior to any surgical intervention.

Intraspecific variation in fine root morphology of European beech: a root order-based analysis of phenotypic root morphospace.

Fine roots are multifunctional organs that may change function with ageing or root branching events from primarily absorptive to resource transport and storage functions. It is not well understood, how fine root branching patterns and related root functional differentiation along the longitudinal root axis change with soil chemical and physical conditions. We examined the variation in fine root branching patterns (the relative frequency of 1st to 4th root orders) and root morphological and chemical traits of European beech trees with soil depth (topsoil vs. subsoil) and soil chemistry (five sites with acid to neutral/alkaline bedrock). Bedrock type and related soil chemistry had an only minor influence on branching patterns: base-poor, infertile sites showed no higher fine root branching than base-rich sites. The contribution of 1st-order root segments to total fine root length decreased at all sites from about 60% in the topsoil (including organic layer) to 45% in the lower subsoil. This change was associated with a decrease in specific root area and root N content and an increase in mean root diameter with soil depth, while root tissue density did not change consistently. We conclude that soil depth (which acts through soil physical and chemical drivers) influences the fine root branching patterns of beech much more than soil chemical variation across soil types. To examine whether changes in root function are indeed triggered by branching events or result from root ageing and diameter growth, spatially explicit root physiological and anatomical studies across root orders are needed.

Medial Quadriceps Tendon Femoral Ligament Reconstruction for Anatomic Reconstruction of the Medial Patellofemoral Complex

The medial patellofemoral complex (MPFC) refers to the primary restraint to lateral patellar translation. Originally thought of as the medial patellofemoral ligament, anatomic studies over the past 10 years have identified the additional fibers that attach to the quadriceps tendon, which some have termed the medial quadriceps tendon femoral ligament. Anatomic studies have demonstrated that the MPFC midpoint is at the junction of the medial border of the quadriceps tendon and the articular surface of the patella, indicating that fixation can be on either structure. This technique describes a single-bundle reconstruction technique with anatomic fixation on the quadriceps tendon at the MPFC midpoint that involves fixation on the extensor mechanism first.

Transpalpebral transorbital endoscopic lateral approach to the middle cranial fossa: anatomical study in cadaver

Transorbital expanded endoscopic approaches allow different areas of the skull base to be approached. The aim of our study is to analyse the main anatomical bone and neurovascular structures of the middle cranial fossa by means of a transpalpebral transorbital lateral endoscopic approach (TTLEA). An anatomical study was performed on 12 orbital cavities corresponding to 6 cadaver heads. All specimens were previously injected with colored latex through both carotid systems. The mean distance from the orbital rim to the zygomatic-facial foramen and to the zygomatic-temporal foramen was 11 mm and 16 mm respectively. In all cases the meningo-orbital foramen was found at a mean distance from the orbital rim of 34 mm. The superior orbital fissure (SOF) was located posterior to the meningo-orbital foramen at 39 mm. The foramen rotundum and foramen ovale were located separated from each other by 10 mm on average. Anterior to the foramen ovale a bony prominence was observed in all cases. In 11 cases (92%) the entrance of the accessory meningeal artery into the foramen ovale was evident and in one case an accessory foramen was observed. The middle meningeal artery was located in all dissections within the foramen spinosum. The TTLEA offers a wide and direct exposure of the middle cranial fossa. It should be considered as an alternative to transcranial approaches in certain lesions invading the lateral region of the middle cranial fossa, the lateral wall of the cavernous sinus or the infratemporal fossa.

Anatomical study of the branching pattern of the right coronary artery

Background: The frequency of coronary artery disease is increasing nowadays. A detailed idea about the normal and variant anatomy of coronary arteries is essential in the management of various heart diseases, especially coronary bypass surgeries. Aims and Objectives: The aims and objectives of the study are to study the branching pattern of the right coronary artery (RCA). Materials and Methods: One hundred adult heart specimens were collected from the Department of Anatomy, Government Medical College, Kottayam. The specimens were fixed in formalin and the RCA was traced from origin to termination. Emphasis was given to the variations in branching patterns. Results: The incidence of a third coronary artery was 20%. The origin of the sinoatrial (SA) nodal artery from both the RCA and the left circumflex artery was 7%. The incidence of the double posterior descending artery was 9%. Short RCA terminating near the right margin was 4%. Long RCA reaching up to left margin was 4%. Conclusion: The SA nodal artery arose from RCA in the majority of cases. The posterior descending artery was single in most of the cases and its most common site of termination was up to three-quarters of the way down the posterior interventricular sulcus. In about half of the cases, the Atrioventricular nodal artery took origin from RCA. There was no statistically significant association between origin of the conus artery and gender. A statistically significant association was not observed between the origin of SA Nodal artery and gender.

Anatomic study of flexor carpi ulnaris and brachioradialis muscles and their implication in reconstructive surgeries

Management of soft tissue loss around the posterior aspect of the elbow region is most challenging for clinicians, as it may require reconstructive methods for the better healing of wounds. One of the options for reconstructive surgery is local muscle rotational flaps by the flexor carpi ulnaris (FCU) and brachioradialis (BR). This study aimed to explore the morphometry and vascular anatomy of FCU and BR. Thirty formalin-embalmed cadaveric upper extremities (16 right and 14 left) were utilized for this study. The average length of the FCU muscle belly was 28.96 ±2.16 cm within a range of 24.3 to 32.5 cm, and the average length of the tendon was 10.05 ± 2.2 cm, with a range of 6.9 to 14.3 cm. The number of vascular pedicles for FCU was one in 5, two in 21, and three and four in 2 specimens respectively. All the pedicles arose from the ulnar artery. The average length of the BR muscle was 28.2 ±3.58 cm, with a range of 22.8 to 36.8 cm, and the average length of its tendon was 8.2 cm, with a range of 5.7 to 13.5 cm. In 90% of specimens, BR had only one vascular pedicle and in 10% there were two pedicles. These pedicles arose from the radial recurrent artery and the radial artery. Detailed morphometric and topographic anatomy of the vascular pedicles of FCU and BR are provided in this study, which can be considered the morphological database for the South Indian population.

Infraorbital canal variants and its clinical and surgical implications. A systematic review.

Recent literature highlights anomalous cranial nerves in the sinonasal region, notably in the sphenoid and maxillary sinuses, linked to anatomical factors. However, data on the suspended infraorbital canal (IOC) variant is scarce in cross-sectional imaging. Anatomical variations in the sphenoid sinuses, including optic, maxillary, and vidian nerves, raise interest among specialists involved in advanced sinonasal procedures. The infraorbital nerve's (ION) course along the orbital floor and its abnormal positioning within the orbital and maxillary sinus region pose risks of iatrogenic complications. A comprehensive radiological assessment is crucial before sinonasal surgeries. Cone-beam computed tomography (CBCT) is preferred for its spatial resolution and reduced radiation exposure. The aim of this study was to describe the prevalence of anatomical variants of the infraorbital canal (IOC) and report its association with clinical condition or surgical implication. We searched Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to June 2023. Two authors independently performed the search, study selection, data extraction, and assessed the methodological quality with assurance tool for anatomical studies (AQUA). Finally, the pooled prevalence was estimated using a random effects model. Preliminary results show that three types are prevalent, type 1: the IOC does not bulge into the maxillary sinus (MS); therefore, the infraorbital foramen through the anterior wall of MS could be used for identification of the ION. Type 2: the IOC divided the orbital floor into medial and lateral aspects. Type 3: the IOC hangs in the MS and the entire orbital floor lying above the IOC. From which the clinical implications where mainly surgical, in type 1 the infraorbital foramen through the anterior wall of MS could be used for identification of the ION, while in type 2, since the lateral orbital floor could not be directly accessed an inferiorly transposition of ION is helpful to expose the lateral orbital wall directly with a 0 scope; or using angled endoscopes and instruments, however, the authors opinion is that direct exposure potentially facilitates the visualization and management in complex situations such as residual or recurrent mass, foreign body, and fracture located at the lateral aspect of the canal. Lastly, in type 3, the ION it's easily exposed with a 0° scope. This systematic review identified four IOC variants: Type 1, within or below the MS roof; Type 2, partially protruding into the sinus; Type 3, fully protruding into the sinus or suspended from the roof; and Type 4, in the orbital floor. Clinical recommendations aim to prevent nerve injuries and enhance preoperative assessments. However, the lack of consistent statistical methods limits robust associations between IOC variants and clinical outcomes. Data heterogeneity and the absence of standardized reporting impede meta-analysis. Future research should prioritize detailed reporting, objective measurements, and statistical approaches for a comprehensive understanding of IOC variants and their clinical implications. Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/UGYFZ .

Anatomy of the brain of capybara (Hydrochoerus hydrochaeris) using magnetic resonance imaging.

Capybara is considered the largest living rodent and is widespread distributed in the South America and in the Brazilian territory. The purpose of this study was to provide the anatomical description of the brain in the capybara (Hydrochoerus hydrochaeris) using magnetic resonance imaging (MRI). Brains of ten normal capybaras were imaged and sectioned in the anatomical studies. MRI was acquired on 0.25 Tesla equipment, promoting good-quality images capable to identify and classify the main anatomical structures of clinical interest. MRI reference images were validated by comparing them with gross anatomical sections. The capybara sulci and gyri were named for its similar location and orientation to those described in the previous descriptions in the capybara and in the domestic dog. Capybaras presented prominent cerebral sulcus and gyrus in relation to other caviomorph rodents, but in reduced number when compared to domestic animals and other wild mammals such as elephants and giraffes. The findings of this study indicate that the shape of the capybara brain is remarkably similar to that of the caviomorph rodents with a higher neocortilization. The capybara rhinencephalon was well-developed implying a good sense of smell. Due to this development of the rhinencephalon, we can suggest that capybara brain is a macrosmatic brain. The MRI and gross anatomical sections of capybara brain may help veterinary researchers and clinicians increase the accuracy of brain MRI scans interpretation in these animals.

Functional anatomy of the limbic system structures involved in the development of post-traumatic stress disorder: analysis of anatomical and clinical studies

We present an analysis of anatomical and clinical studies investigating the morphological and functional characteristics of various structures of the limbic system involved in the development of post-traumatic stress disorder (PTSD). Understanding the structural organization and functional interactions of this system will provide new insights into the mechanisms underlying PTSD. The results of various morphological and clinical studies are considered, including information on the architecture and interconnections of the structures of the limbic system and their alteration by traumatic events. The generalized results provide new data on the role of the individual structures of the limbic system in the development of PTSD, enabling more accurate prediction of the development of PTSD and prompt appropriate measures to alleviate the course of this disorder

Hindlimb Skeletal Structure of the Green-winged Macaw: An Anatomical Study

In birds, the forelimb bones undergo modification to facilitate muscle attachment for flight, enabling the movement of wings up and down. Conversely, hindlimb bones primarily support walking and perching functions, necessitating evolutionary adaptations in their structure. Therefore, this study aims to document the gross anatomical features of hind limb bones in Green-winged Macaws, including the femur, tibio-tarsus, tarsometatarsus, and digits. The bones were sourced from six Green-winged Macaw carcasses undergoing post-mortem examination at the Department of Veterinary Pathology, Madras Veterinary College, Chennai. Preparation was conducted using the wet maceration technique. In the femur, the proximal end displayed a large, well-defined spherical head medially, accompanied by a small depression called the fovea capitis, and a distinct neck. The tibio-tarsus exhibited a small roughened area on its lateral border for fibula attachment, with a larger medial and smaller lateral condyle at the proximal extremity, along with a linear cinemal crest along the medial border. The fibula's distal extremity tapered into a free point, articulating at the caudolateral aspect of the tarsometatarsus. The tarsometatarsus displayed fused distal tarsals with metatarsals II, III, and IV, while Metatarsus I remained a separate bone, forming the base of the first toe. The proximal extremity of the tarsometatarsus featured two large concave articular facets for condyles from the distal extremity of the tibio-tarsus, and a facet for the distal end of the fibula caudolaterally. The Macaw's hind limb consisted of four digits, forming a zygodactyl foot arrangement.