The accessory nerve is an important nerve in the head and neck regions. Some variants of this nerve's anatomy have been reported. Herein, we present an unusual report and review the extant medical literature regarding other more commonly found derailments of this nerve's anatomy.
accessory nerve; internal jugular vein; sternocleidomastoid muscle; variations
Posterior dissection of the left lateral neck
Trapezius is reflected from its midline and scapular attachments and moved superolaterally to view its deep surface.
Repeat of Figure Figure11 emphasizing the neural loop (arrows) formed on the deep surface of the trapezius muscle and made up of one-half of distal fibers of the C4 ventral ramus and one-half from the distal accessory nerve to the trapezius
Cureus. 2018 Jun 5;10(6):e2736. doi: 10.7759/cureus.2736.
The fabella is a sesamoid bone that is embedded in the lateral head of the gastrocnemius muscle and often articulates directly with the lateral femoral condyle. It is present in 10-30% of the general population with a higher incidence in Asians. The fabella can lead to various pathologies such as fabella pain syndrome and common fibular nerve palsy. Conservative treatment involves physical therapy or injecting local anesthetics or steroids around this bone. However, if symptoms persist, then a fabellectomy can be performed. Physicians should be aware of the fabella bone and the multiple pathologies associated with it in order to provide the best treatment and management for patients.
anatomy; fabellectomy; femoral condyle; gastrocnemius; knee pain; sesamoid; shock wave therapy; variations
Posterior view of the distal left thigh and proximal leg.
Note the fabella as seen within the proximal tendon of the lateral head of the gastrocnemius.
Zoomed in view of Figure Figure11 noting the fabella (circle).
After removal (right image), the fabella was found to be bony in nature and approximately 1 cm in diameter.
Childs Nerv Syst. 2018 Jun;34(6):1095-1101. doi: 10.1007/s00381-017-3462-6. Epub 2017 May 29.
Tubbs RI, Gonzales J, Iwanaga J, Loukas M, Oskouian RJ, Tubbs RS.
Leonardo da Vinci (1452-1519) can be called one of the earliest contributors to the history of anatomy and, by extension, the study of medicine. He may have even overshadowed Andreas Vesalius (1514-1564), the so-called founder of human anatomy, if his works had been published within his lifetime. While some of the best illustrations of their time, with our modern knowledge of anatomy, it is clear that many of da Vinci's depictions of human anatomy are inaccurate. However, he also made significant discoveries in anatomy and remarkable predictions of facts he could not yet discover with the technology available to him. Additionally, da Vinci was largely influenced by Greek anatomists, as indicated from his ideas about anatomical structure. In this historical review, we describe da Vinci's history, influences, and discoveries in anatomical research and his depictions and errors with regards to the musculoskeletal system, cardiovascular system, nervous system, and other organs.
J Craniofac Surg. 2018 Jun;29(4):1069-1071. doi: 10.1097/SCS.0000000000004425.
Trauma to the mandible can occasionally be a life-threatening event. Although extremely rare with only 56 reported patients in the English language, fracture of the floor of the middle cranial fossa with protrusion of the mandibular condyle into the middle cranial fossa was first reported in 1963 by Dingman. The authors review the anatomy of the temporomandibular joint in relation to the middle cranial fossa and demonstrate the possible complications due to condylar intrusion with anatomical dissection.
Surg Radiol Anat. 2018 Jun;40(6):647-652. doi: 10.1007/s00276-018-2005-5. Epub 2018 Mar 29.
Kikuta S, Iwanaga J, Nakamura K, Hino K, Nakamura M, Kusukawa J.
The retromolar canal (RMC) and foramen (RMF) are anatomic variants in the retromolar area of the mandible. The purpose of this study was to clarify the relationship between the RMC and RMF and related complications, and to reveal how the RMC could impact the mandibular anatomy using cone-beam computed tomography (CBCT) and panoramic images (PAN).
CBCT and PAN images of 50 patients were retrospectively analyzed to investigate the morphology of the RMC and RMF, and their impact on impacted third molar surgery and orthognathic surgery.
In PAN images, neither the RMC nor RMF was detected. In CBCT images, the RMCs were detected in 26% (13/50) of the patients. A double RMC was detected on one side of one patient. The diameter of the RMC ranged from 0.8 to 2.9 mm (mean; 1.5 ± 0.6 mm), and the RMF ranged from 0.6 to 2.3 mm (mean; 1.1 ± 0.5 mm). No patients experienced unexpected bleeding. Unilateral postoperative hypoesthesia of the buccal gingiva in the molar region was reported in 6.7% of patients with the RMC.
Hypoesthesia of the buccal gingiva in the lower molar region may be the main complication when the RMC is damaged.
Anatomic variation; Cone-beam computed tomography; Mandible; Oral surgery; Retromolar canal; Retromolar foramen
Cureus. 2018 May 31;10(5):e2716. doi: 10.7759/cureus.2716.
Telesurgery uses wireless networking and robotic technology to allow surgeons to operate on patients who are distantly located. This technology not only benefits today's shortage of surgeons, but it also eliminates geographical barriers that prevent timely and high-quality surgical intervention, financial burden, complications, and often risky long-distance travel. The system also provides improved surgical accuracy and ensures the safety of surgeons. In this paper, we describe the current trend of telesurgery's innovative developments and its future.
haptic feedback; latency time; robotic surgery; telemedicine; telesurgery; travel medicine; virtual interactive presence
Cureus. 2018 May 13;10(5):e2615. doi: 10.7759/cureus.2615.
During a routine anatomical dissection of the right brachium of a 68-year-old male cadaver, an extremely rare variation of the coracobrachialis longus muscle was discovered. It started from the medial surface of the middle part of the humerus with a well-formed muscle portion and then continued into the well-presented distal tendinous portion, which was attached to the medial epicondyle of the humerus. We also briefly review the reported variations of the coracobrachialis and their potential clinical significance.
coracobrachial variations; humeroepitrochlearis muscle
Cureus. 2018 May 10;10(5):e2604. doi: 10.7759/cureus.2604.
A previously undescribed variant ulnar nerve loop was discovered during the routine anatomic forearm and hand dissection of an adult female. The major finding was that of a large loop traveling around the distal tendon of the flexor carpi ulnaris. The variation presented here appears to be unique. The exact function of such derailed anatomy is not clear but, if found during surgery, might confound normal dissection methods or, when present, could result in varied clinical presentations regarding the sensory or motor examination of the hand.
anatomy; anomalies; cadaveric; hand surgery; loop; ulnar nerve; variations
Left Anterior Forearm and Hand Dissection
Figure Figure1A:1A: Left palmar surface of the left hand and distal anterior forearm displaying the ulnar nerve in its anatomical position (arrowheads).
Figure Figure1B:1B: Figure Figure1A1A with the ulnar nerve main trunk rotated 180 degrees and then retracted medially. Note the variant loop formed around the flexor carpi ulnaris. White arrowheads: ulnar nerve main trunk; Black arrowheads: variant loop around the distal tendon of the flexor carpi ulnaris; White arrow: deep branch of the ulnar nerve; Superficial branch of the ulnar nerve retracted at right forceps; Red arrow: additional nervous interconnection; Green arrow: Riché-Cannieu anastomosis between the superficial ulnar nerve branch and median nerve in the hand.
Clin Anat. 2018 May;31(4):521-524. doi: 10.1002/ca.23069. Epub 2018 Mar 25.
Henry BM, Vikse J, Pekala P, Loukas M, Tubbs RS, Walocha JA, Jones DG, Tomaszewski KA.
Unambiguous reporting of a study's compliance with ethical guidelines in anatomical research is imperative. As such, clear, universal, and uniform reporting guidelines for study ethics are essential. In 2016, the International Evidence-Based Anatomy Working group in collaboration with international partners established reporting guidelines for anatomical studies, the Anatomical Quality Assurance (AQUA) Checklist. In this elaboration of the AQUA Checklist, consensus guidelines for reporting study ethics in anatomical studies are provided with in the framework of the AQUA Checklist. The new guidelines are aimed to be applicable to research across the spectrum of the anatomical sciences, including studies on both living and deceased donors. The authors hope the established guidelines will improve ethical compliance and reporting in anatomical research. Clin. Anat. 31:521-524, 2018.
© 2018 Wiley Periodicals, Inc.
anatomy; ethics; methodology; reporting guidelines; research
Although the embryology of the posterior cranial fossa can have life altering effects on a patient, a comprehensive review on this topic is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the posterior cranial fossa is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of its bony architecture is important for those treating patients with involvement of this region of the cranium. Clin. Anat. 31:466-487, 2018.
© 2018 Wiley Periodicals, Inc.
Chiari malformation; anatomy; hindbrain; spine
Clin Anat. 2018 May;31(4):462-465. doi: 10.1002/ca.23047. Epub 2018 Feb 22.
Iwanaga J, Nakamura K, Alonso F, Kirkpatrick C, Oskouian RJ, Watanabe K, Tubbs RS.
The minor salivary glands in the retromolar trigone have rarely been studied. The aim of this study was to better define the anatomy of the minor salivary glands in the retromolar trigone and establish the relationships between these and adjacent structures. The gland in the retromolar trigone was exposed and its relationships to surrounding structures were observed on 20 cadaveric sides. The boundaries of the gland included the superior pharyngeal constrictor muscle, the tendon of the buccinator muscle, and loose connective tissue. The gland was not continuous with the pterygomandibular or parapharyngeal spaces, but loose connective tissue was present between glands in the retromolar trigone and the medial pterygoid muscle. To our knowledge, this is the first study to describe the detailed anatomy of the minor salivary gland in the retromolar trigone. We suggest that the minor salivary gland in the retromolar trigone should be named the "retromolar gland." Clin. Anat. 31:462-465, 2018.
© 2018 Wiley Periodicals, Inc.
anatomy; mandible; metastasis; minor salivary glands; tumor
Although pathology of the hindbrain and its derivatives can have life altering effects on a patient, a comprehensive review on its embryology is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the hindbrain is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of the hindbrain is important for those treating patients with involvement of this region of the central nervous system. Clin. Anat. 31:488-500, 2018.
© 2018 Wiley Periodicals, Inc.
Chiari; anatomy; brain stem; brain, nervous system; cerebellum; genetics; malformation
J Plast Reconstr Aesthet Surg. 2018 May;71(5):665-669. doi: 10.1016/j.bjps.2017.12.004. Epub 2017 Dec 13.
The course of the nerves along the nasal septum has not been clearly studied, and surgical procedures such as rhinoplasty require a more detailed topography of the nerve supply inside the septum. Therefore, we aimed to investigate the distribution of the internal nasal branch of the infraorbital nerve inside the nasal septum and to define the relationship between it and the nasal cartilages.
Fourteen sides from eight fresh frozen and embalmed Caucasian cadaveric heads were dissected. The specimens were derived from three males and five females. The ages of the cadavers at death ranged from 65 to 84 years. The course of the internal nasal branch and its relationship between the nasal cartilages were observed using a surgical microscope.
On all sides, the internal nasal branch approached the medial crus of the major alar cartilage from behind and traveled anteriorly below the medial crus of the major alar cartilage while giving off anterior inferior septal, middle inferior septal, and posterior inferior septal branches.
Based on the results of this study, we suggest that procedures of the nasal cavity such as rhinoplasty could be modified to avoid injuring the main trunk of the internal nasal branch of the infraorbital nerve inside the nasal septum.
Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Anatomy; Cosmetic surgery; Nasal septum; Nose; Rhinoplasty; Trigeminal nerve
World Neurosurg. 2018 May;113:397. doi: 10.1016/j.wneu.2018.02.018.
Pedicle screws placed into C2 necessitate a thorough understanding of this bone's unique anatomy. Although multiple landmarks and measurements have been used by surgeons, these are often varied in the literature with no consensus. Herein, we studied one recently proposed landmark using the nutrient foramina of the posterior aspect of C2 for pedicle screw placement.
On 19 (38 sides) C2 dry bone specimens, the presence, size, location, and distance from the midline of the nutrient foramina found at the junction between the isthmus and lamina were documented and measured. In addition, to discern the source of the artery entering such foramina, an injected adult cadaver was dissected.
The number of foramina ranged from 0-5 with a mean of 1.84. On 3 sides, no foramina were identified. The mean diameter of the foramina was 0.57 mm. The location of the foramina was at position 1 on 9.5% of sides, position 2 on 66.4% of sides, and position 3 on 24.1% of sides. The mean horizontal distance from the midline of the spinous process of C2 to the foramina was 25.17 mm. In the cadaveric specimen, the source of the artery entering these C2 nutrient foramina was found to be distal branches of the deep cervical artery.
We found the nutrient foramina of the C2 laminae are useful for pedicle screw placement. However, there are minor variations of the number and position of these structures. Lastly, on the basis of our study, 7.9% (n = 3) of sides will not have such foramina.
Copyright © 2018 Elsevier Inc. All rights reserved.
Anatomy; Axis; Cervical spine; Landmarks; Pedicle screw
World Neurosurg. 2018 May;113:e296-e301. doi: 10.1016/j.wneu.2018.02.009. Epub 2018 Feb 10.
Yilmaz E1, Abdul-Jabbar A2, Tawfik T2, Iwanaga J3, Schmidt CK3, Chapman J2, Blecher R2, Tubbs RS4, Oskouian RJ5.
The S2 alar-iliac (S2AI) screw is a modification of the iliac fixation technique using the space between the neuroforamina of S1 and S2 as an insertion point to fix the sacrum to the ilium. To our knowledge, an anatomic review of the S2AI technique has not been described and the insertion point is vague and angles differ in reports from the literature. The purpose of the current anatomic illustration is to provide step-by-step techniques with fluoroscopic imaging to help confirm the safe placement of S2AI screws.
The procedure was performed on the left and rights sides of a fresh, frozen, and thawed predissected male cadaver in a surgical training facility through a standard posterior midline exposure for placement of the S2AI screws. All screws were placed by a fellowship-trained spine surgeon and an attending spine surgeon.
The specimen was placed prone, and a midline incision begun at the L4 or L5 spinous process. Using the anteroposterior and inlet views, the S1 dorsal sacral foramen, the S1 endplate, and the sacroiliac joint can be identified. The insertion point is 10 mm laterally between the S1 and S2 foramina and near to the sacroiliac joint. Aim toward the anterior inferior iliac spine is ensured by using a 30°-40° lateral angulation in the transverse plane and 20°-30° caudal angulation in the sagittal plane depending on the sacral angulation. Using lateral fluoroscopy, the acetabulum and greater sciatic notch can be identified and screw misplacement can be avoided. The screw length is measured and is usually between 60 and 90 mm (8- to 9-mm diameter). An elevator is used to identify the outer sacral cortex. Anteroposterior, obturator-outlet, and teardrop views are used to ensure correct screw insertion.
Fluoroscopic guidance is crucial for optimal S2AI screw placement. Using the described technique allows a safe and correct insertion of the S2AI screw.
Copyright © 2018 Elsevier Inc. All rights reserved.
Lumbopelvic fixation; S2AI; Sacrum; Spinopelvic fixation; Technique
Cureus. 2018 Apr 18;10(4):e2501. doi: 10.7759/cureus.2501.
Brandmeir N, Payne R, Rizk E, Tubbs RS, Arsuaga JL, Bartsiokas A.
Objective King Philip II, the father of Alexander the Great, suffered a penetrating wound to the leg from a spear that left him severely handicapped. His skeletal remains represent the first and only case of an injury from ancient Greece that can be directly compared to its historical record. The objective of the study was to confirm the identity of the male occupant of Royal Tomb I in Vergina, Greece as Philip II of Macedonia by providing new evidence based on anatomical dissection and correlation with the historical description of the wounds. Methods Radiographs and photographs of the leg in Royal Tomb I in Vergina were examined. Anatomical dissection of a cadaver with a reconstructed wound similar to Philip's was also completed to identify associated soft-tissue injuries. Results The left leg was penetrated by an object at the knee which resulted in joint diastasis, external rotation of the tibia, knee ankylosis, and formation of a granuloma around the related object. This caused massive trauma to the joint but spared the popliteal artery. This resulted in ligamentous injury as well as injury to the peroneal nerve and probably the tibial nerve, resulting in a complete palsy of those nerves. Conclusion This evidence exactly matches the historical sources and shows conclusively that the leg and Tomb I belong to Philip II. The anatomic and archaeologic evidence also serve as independent verification of some of the historical record of that period, better enabling scholars to judge the reliability of various texts. Furthermore, it gives invaluable information about surgical practices in ancient Greece according to Hippocratic methods and their outcomes. Finally, this sheds new light on the occupants of Royal Tomb II including the fact that the armor recovered there may have belonged to Alexander the Great.
alexander the great; joint granuloma; knee granuloma; peroneal nerve injury; philip ii
Views of Philip’s Leg
A: Lateral view of the knee joint with a pen demonstrating the persistent space from the wound tract and foreign body granuloma and surrounding ankylosis. B: Posterior view of the knee joint along with the persistent space from the wound and foreign body granuloma and surrounding ankylosis. C: Axial CT scan through the injured joint space oriented perpendicular to the long axis of the femur. White triangle arrowheads point to areas of post-mortem damage identified by lack of compact bone on the surface and fracture lines separating continuous channels in the cancellous bone. Orange chevron arrowheads demonstrate reactive sclerotic bone on the walls of the granuloma. Note the osteolytic nature of the lesion with some sclerotic changes around the hole typical of lesions resulting from foreign body granulomas. D: Axial CT scan through the femoral condyles oriented perpendicular to the long axis of the femur. The yellow arrow represents normal cortical bone on the surface of the femoral condyles, whose shape can be appreciated. E: Axial CT scan of the injured joint space at a level inferior to the intercondyloid fossa oriented perpendicular to the long axis of the tibia. The hole can be seen along its major axis (green arrow). The difference between the abnormal bone lining the hole (orange chevron) and the normal cortical bone along the inferior limit of the femoral condyle (yellow arrow) can easily be distinguished. F: Axial CT scan of the joint space at the level of the intercondyloid fossa oriented perpendicular to the long axis of the tibia. The yellow arrow represents normal cortical bone on the femoral condyles, whose shape can be appreciated. Note that the bone surrounding the intercondyloid fossa is evenly corticated, differentiating it from the granuloma space.
Labels - Brackets: femoral condyles, Red arrow: Tibial plateau, Green block arrow: wound tract, Blue triangle arrow: Intercondyloid fossa, A: Anterior, L: Left
Demonstration of the Femoral Condyles and Joint Space Granuloma
A: Posterior view of the specimen (below) with a sex and length match sample showing the condyles above it in parallel. B: En face view of the femoral condyles demonstrating the separation of the intercondyloid fossa from the wound tract. The dashed line to the left shows parallel structures. Blue line is the anterior femoral surface; note how the hole in the bone is distal to the intercondyloid fossa. C: posterior-anterior projection X-ray of the knee wound showing the inferior limit of the femoral condyles (red arrows) and wound tract granuloma space (green arrow). D: Lateral X-ray of the knee showing the inferior limit of the femoral condyles (red arrow) and the joint space granuloma (green arrow).
Labels - Red skinny arrow: inferior limit of the femoral condyles, Green block arrow: joint space granuloma from wound tract, Blue triangular arrowhead: Intercondyloid fossa. Scale = 5 cm in C and D.
Cadaveric Dissection Recreating Philip’s Injury
A: View of an example trajectory. Note how the spear enters medially to the long head of the biceps femoris and exits in the joint space between the femoral condyles. B: Close-up view of the dissection with anatomic structures labeled. C: Lateral oblique X-ray of cadaver specimen with a recreated injury. Note the joint diastasis similar to the knee of the specimen from Tomb I as well as the external rotation of the tibia. The penetrating foreign body can be seen as well. The red arrow represents the medial femoral condyle, the dashed bracket shows the joint space. D: Close-up view of the lateral aspect of the knee and popliteal fossa with the spear inserted. Note how the spear must either divide or radically displace the peroneal nerve to achieve this trajectory and also how this trajectory spares the large vessels of the popliteal fossa.
Labels - 1: Fibular head, 2: Peroneal nerve, 3: Popliteal artery and vein, 4: Biceps femoris, 5: Gastrocnemius.
Cranial nerve foramina are integral exits from the confines of the skull. Despite their significance in cranial nerve pathologies, there has been no comprehensive anatomical review of these structures. Owing to the extensive nature of this topic we have divided our review into two parts; Part II, presented here, focuses on the foramina of the posterior cranial fossa and discusses each foramen's shape, orientation, size, surrounding structures, and structures that pass through it. Furthermore, by comparing foramen sizes against the cross-sectional areas of their contents, we determine the amount of free space available within each. We also review lesions that can obstruct each foramen and discuss the clinical consequences.
cranial nerve; foramen; foramen magnum; hypoglossal canal; internal acoustic meatus; jugular foramen; posterior fossa; skull base
Cureus. 2018 Apr 13;10(4):e2473. doi: 10.7759/cureus.2473.
The arrow is one of the oldest weapons invented that has ties back to ancient civilization. With the advancement of modern weaponry, literature concerning the management of this traumatic wound has dwindled. However, there are older written accounts that have led to our understanding of how we manage injuries inflicted by the arrow. One of the more comprehensive accounts was produced in the 19th century by a United States (US) Lieutenant Colonel named JH Bill. Recent cases in forensic pathology, as well as instances of trauma concerning arrowhead injuries, have documented a lack of comprehensive literature for the management of such injuries. Thus, the goal of our review is to evaluate the literature and provide a record of the different presentations, complications, and ways to manage arrow injuries.
arrowhead; management; penetrating injury; trauma
Extraction of non-impacted arrowheads
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
For arrowheads embedded in bone
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
Bill's extraction tool for arrowheads impacted in bone
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
Crocodile forceps for fragmented arrowheads
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
Arrow impacting the superciliary ridge (left). On the right are images of an arrowhead impacted in rib cages of a buffalo.
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
Arrowhead lodged in the zygomatic arch.
Figure copied from: Bill JH: Sabre and bayonet wounds; arrow wounds. International Encyclopedia of Surgery: A Systematic Treatise on the Theory and Practice of Surgery By Authors of Various Nations. Ashhurst J (ed): William Wood & Co, New York; 1882. 2:101-117
Cureus. 2018 Apr 10;10(4):e2460. doi: 10.7759/cureus.2460.
Patel M1, Iwanaga J2, Oskouian RJ3, Tubbs RS4.
Counterintuitive to anatomic organization is the communication between a dorsal ramus and a ventral ramus, which are traditionally taught as serving specific anatomical fields. Herein, we discuss the cadaveric findings of such an example of neural intercommunication between the dorsal and ventral rami and review the potential embryology. While these two nerves are complementary in their function, it is not understood as to the reason for such an anatomical connection that breaches normal anatomical "laws."
anatomy; cadaver; cervical plexus; dissection; dorsal ramus; greater occipital nerve; lesser occipital nerve; spinal nerve; ventral ramus
