An anatomical illustration of the human hand and wrist (anterior palmar view), highlighting the peripheral nerves and the carpal tunnel. The image depicts the skeletal structure of the carpus, metacarpals, and phalanges, overlaid with musculature and major nerves in yellow. Key structures are labeled: the median nerve is shown passing deep to the flexor retinaculum (transverse carpal ligament), demonstrating its entry into the carpal tunnel. The ulnar nerve is positioned medially (ulnar side), passing superficial to the flexor retinaculum, while the superficial branch of the radial nerve is shown laterally near the radius. Distal to the wrist, the nerves are shown branching into digital nerves to provide sensory and motor innervation to the fingers. This diagram is clinically relevant for explaining the pathophysiology of Carpal Tunnel Syndrome, where the median nerve undergoes compression beneath the flexor retinaculum. Target audience: medical students and clinicians studying upper limb anatomy and entrapment neuropathies.

This medical infographic illustrates common peripheral nerve injury (PNI) sites in survivors of severe COVID-19. The central element is an anatomical diagram of a human figure highlighting several nerves with color-coded injury frequencies. The ulnar nerve (25.1%) is the most frequent site, followed by the common fibular (15.8%), sciatic (13.1%), median (9.8%), brachial plexus (8.7%), and radial (8.2%) nerves. A color-gradient scale (5% yellow to 30% purple) correlates with these frequencies. Two inset clinical photographs demonstrate stage-related skin pressure sores (decubitus ulcers) at critical compression points. The top inset shows an elbow ulcer with central necrosis and surrounding erythema, while the bottom inset depicts a pressure sore over the fibular head on a limb with darker skin pigmentation. Both clinical images include a surgical ruler for scale. The visual summarizes how mechanical loading during prolonged ICU hospitalization and prone positioning can lead to both skin breakdown and underlying axonal nerve injury, emphasizing the clinical relevance of monitoring bony prominences.

Anatomical diagram of the human hand and distal forearm in a palmar view, illustrating peripheral nerve anatomy and muscle transposition for pronator quadratus opponensplasty. The diagram features color-coded structures overlaid on a skeletal and soft tissue outline. Major peripheral nerves, including the median and ulnar nerves, are highlighted in yellow, showing their proximal courses and distal branching into digital nerves. The recipient anterior interosseous nerve (AIN) motor branch is highlighted in red, indicating its path toward the transposed muscle. The donor recurrent median nerve and donor deep ulnar nerve branches are highlighted in green, demonstrating potential donor sites for nerve coaptation to restore thenar function. The pronator quadratus muscle is shaded in red, shown in a transposed position toward the thumb (thenar eminence) to simulate its role as an opponens substitute. This illustration is designed for surgical planning in cases of chronic carpal tunnel syndrome or atrophic thenar muscle dysfunction, focusing on the spatial relationships required for effective nerve transfer and muscle mobilization.

A multi-panel series illustrating a peripheral nerve injury and repair procedure in an animal model (rat forelimb), used for neuroanatomical and microsurgical education. Panel A is a schematic diagram showing the anatomical pathway of the ulnar, median, and radial nerves in the right forelimb, with an inset detailing a tubular nerve repair technique. Panel B shows a clinical photograph of a skin incision proximal to the elbow with orientation markers (R-L, M-C). Panel C provides a high-magnification intraoperative view of the isolated ulnar, median, and radial nerves, with the radial nerve specifically targeted for intervention. Panel D demonstrates the microsurgical tubular repair of a completely transected radial nerve. The proximal and distal nerve stumps are shown sutured 1 mm into the opposite ends of a 6-mm saline-filled polyurethane tube, leaving a 4-mm internal gap. This visual serves to demonstrate experimental peripheral nerve regeneration models, microsurgical suturing techniques, and the use of conduit-based bridging for segmental nerve defects.

A 3D anatomical reconstruction showcasing the segmentation and spatial orientation of the 12 pairs of human cranial nerves (CN I–XII). The image presents two views: a lateral perspective within a partially transparent skull (left) and an anterior-inferior view relative to the brain and brainstem (right). Each nerve is color-coded for identification: CN I (Olfactory), CN II (Optic) with the optic chiasm and tract, CN III (Oculomotor), CN IV (Trochlear), CN V (Trigeminal) including V2 (maxillary) and V3 (mandibular) divisions, CN VI (Abducens), CN VII (Facial), CN VIII (Vestibulocochlear), CN IX (Glossopharyngeal), CN X (Vagus), CN XI (Accessory), and CN XII (Hypoglossal). Key inner ear structures, including the snail-shaped cochlea and the loop-like semicircular canals, are visualized in relation to the facial and vestibulocochlear nerves. This diagnostic-quality illustration demonstrates the complex neuroanatomical pathways through the skull base and their origins at the brainstem, serving as a pedagogical tool for neurology, radiology, and neurosurgery training.

This medical anatomical diagram provides a lateral view of the human head and neck, focusing on the cervical plexus and its integration with cranial nerves. Key neural structures include the lesser occipital nerve (1), greater auricular nerve (3), and transverse cutaneous nerve of the neck (6), demonstrating the sensory distribution of the cervical plexus. The phrenic nerve (10) is shown descending inferiorly anterior to the prevertebral muscles (18). Cranial nerves X (vagus, 4), XI (accessory, 5), and XII (hypoglossal, 19) are illustrated to show their spatial relationships with cervical spinal branches. Muscular landmarks include the sternocleidomastoid (2, 9), trapezius (7), and infrahyoid muscles such as the omohyoid (11, 15) and thyrohyoid (16). The ansa cervicalis (13) is depicted innervating the sub-hyoid musculature. The diagram also illustrates the sagittal section of the brain and oral cavity, highlighting the innervation of the tongue and the relationship between the cervical spine vertebrae and emerging nerve roots. This resource is intended for medical education regarding the peripheral nervous system and regional anatomy of the neck.

Anatomical diagram of a lateral view of the human skull, specifically focusing on the deep facial nerves and related osteological landmarks. The illustration highlights the trigeminal nerve (CN V) divisions using yellow color-coding. The maxillary nerve (V2) is shown exiting the cranial cavity through the foramen rotundum to enter the pterygopalatine fossa, located anterior to the lateral pterygoid plate. The mandibular nerve (V3) is depicted exiting via the foramen ovale, descending posterior to the lateral pterygoid plate. Key labels include the Pterygopalatine fossa, Maxillary nerve, Foramen ovale, Mandibular nerve, and Lateral pterygoid plate. The diagram serves as an educational resource for understanding the regional anatomy required for performing nerve blocks and identifying neural pathways within the infratemporal and pterygopalatine regions.

This medical illustration depicts four distinct patterns of cranial nerve enhancement (CNE) in an axial anatomical diagram of the skull base and orbits, focusing on the trigeminal and oculomotor regions. (A) Unilateral linear: Post-contrast enhancement (represented in yellow) along the course of a single nerve without an increase in its diameter. (B) Bilateral linear: Symmetrical enhancement of both nerves, maintaining a thin, smooth morphology. (C) Unilateral thickened: Pathological enhancement of one nerve accompanied by increased diameter and an irregular or nodular contour, contrasting with the normal contralateral nerve (white). (D) Bilateral thickened: Symmetrical enhancement and significant enlargement of both nerves with nodular irregularities. These patterns are used in neuroradiology to differentiate between various pathologies, such as viral neuritis (linear patterns) and neoplastic processes like perineural tumor spread or neurolymphomatosis (thickened patterns). The diagram serves as a diagnostic educational tool for classifying imaging findings in magnetic resonance imaging (MRI) and computed tomography (CT) of the cranial nerves.

This clinical photograph shows a surface anatomy projection of the sciatic nerve (ScN) and its branches on the posterior aspect of a patient's left knee and leg. The illustration demonstrates the bifurcation of the sciatic nerve into the medial tibial nerve (TN) and the lateral common peroneal nerve (CPN). From the CPN, the lateral sural cutaneous nerve (LSCN) and the fibular communicating branch (RCF) are shown branching off. On the medial side, the medial sural cutaneous nerve (MSCN) descends from the tibial nerve. These branches converge to form the sural nerve (SuN) in the lower leg. The diagram serves as an educational tool for understanding the peripheral nerve distribution in the popliteal fossa and posterior compartment of the leg, specifically highlighting the pathways relevant to conditions like external popliteal sciatic nerve (EPSN) injuries or peripheral nerve tumors.

This clinical anatomical photograph displays a cadaveric dissection of the posterior lower leg, specifically focusing on the branching patterns of the nerves in the popliteal fossa and posterior calf. The image illustrates the division of the sciatic nerve into the tibial nerve (TN) and common peroneal nerve (CPN). From the tibial nerve, the medial sural cutaneous nerve (MSCN) is seen descending vertically. The lateral sural cutaneous nerve (LSCN) is labeled as a branch of the CPN. A significant anatomical variation is highlighted by a red arrowhead: an additional accessory branch originating from the common peroneal nerve superior to the origin of the LSCN. This branch follows a descending longitudinal course but remains independent, showing no communication or anastomosis with the medial sural cutaneous nerve. This image serves as an educational resource for studying peripheral nerve anatomy and the morphological variations of the sural nerve complex, which is clinically relevant for nerve grafts, biopsies, and understanding compression neuropathies.

Clinical photograph of a 50-year-old male presenting with multi-nerve palsy of the left upper limb involving the radial, median, and ulnar nerves. Panel A shows a side-by-side comparison of the upper extremities; the left hand exhibits a characteristic 'wrist drop' and 'claw-shaped hand' deformity due to extensor and intrinsic muscle weakness. Panel B provides a close-up comparative view of the palmar surfaces. The left hand (right of image) demonstrates significant muscle atrophy, particularly in the thenar and hypothenar eminences, alongside flattening of the forearm flexor group. This visual evidence highlights the motor consequences of prolonged compression (Saturday night palsy/autogenous compression), demonstrating the classic postural signs of combined peripheral nerve injury in the hand and wrist.

A clinical photograph of a male patient demonstrating 'wrist drop' or 'drop hand,' a classic sign of radial nerve palsy. The patient's right hand is shown held in a characteristic posture where the wrist is flexed downward and cannot be actively extended against gravity. The fingers are in a state of passive flexion at the metacarpophalangeal and interphalangeal joints, giving the hand a limp, flaccid appearance. The skin of the forearm and hand appears normal in color and texture, with no obvious swelling or ecchymosis visible in this view. This clinical manifestation is frequently associated with trauma, such as humeral fractures or shoulder dislocations that result in compression or injury to the radial nerve. The image serves as a high-yield educational resource for identifying peripheral nerve injuries during a neurological or orthopedic examination.

Clinical photographs depicting a comparison between normal and abnormal hand gestures used in the physical examination for peripheral nerve injuries. The image is organized in a 2x3 grid. Column 1 (Gesture 1) compares a normal fully extended and abducted hand against a 'wrist drop' or 'finger drop' appearance, typically associated with radial nerve injury. Column 2 (Gesture 2) shows a normal flat palm with fingers adducted against an abnormal posture with inability to fully extend or adduct the medial digits, often seen in ulnar nerve pathology. Column 3 (Gesture 3) demonstrates a normal 'O' sign or precision grip versus an abnormal attempt where the distal phalanges of the thumb and index finger fail to form a circle, indicative of median nerve injury (specifically anterior interosseous nerve). These images illustrate key clinical diagnostic signs including muscle weakness, atrophy, and characteristic postural deviations resulting from traumatic or compressive neuropathies of the upper limb.