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.

This clinical photograph/anatomical diagram hybrid illustrates the sensory distribution of the median nerve on the palmar surface of the right hand. The image displays a human hand against a blue background with a translucent yellow overlay highlighting the specific anatomical region innervated by the median nerve. The highlighted area covers the palmar aspect of the thumb (first digit), index finger (second digit), middle finger (third digit), and the radial half of the ring finger (fourth digit). The boundary line bisects the ring finger longitudinally and extends proximally across the palm toward the wrist, excluding the ulnar-innervated territory of the fifth digit and the ulnar half of the fourth. This visual is an essential educational tool for understanding peripheral nerve entrapment syndromes, specifically Carpal Tunnel Syndrome (CTS), as it clearly demonstrates the regions where patients typically experience paresthesia, numbness, or pain. It serves as a diagnostic reference for clinicians and medical students to correlate physical symptoms with nerve anatomy.

Anatomical diagram and clinical photograph overlaying a human forearm to demonstrate the nerve transfer of the superficial branch of the radial nerve (SBRN) to the median nerve (MN). The visual illustrates the surgical anatomy and morphometric distances required for neurolysis and tension-free coaptation. Key landmarks identified from the lateral epicondyle of the humerus include the SBRN bifurcation (217 ± 7 mm), the radial styloid process (252 ± 6 mm), and the thenar branch takeoff (299 ± 7 mm). The original course of the SBRN is indicated in gray, while the post-transposition path toward the median nerve is shown as a dashed yellow line, with the coaptation site marked by a red dot. A brown highlighted area represents the pronator quadratus muscle. The diagram also specifies an 82 ± 6 mm segment required for interfascicular neurolysis between the median nerve and its thenar branch to facilitate the transfer. This educational material is designed for advanced orthopedic or plastic surgery training in peripheral nerve reconstruction.

This educational image displays the gross anatomy and morphological branching pattern of the human median nerve through dissection. Image A is a clinical photograph showing the median nerve in situ within the medial aspect of the arm and elbow, with the median epicondyle and interosseous nerve labeled as landmarks. Image B presents the fully harvested median nerve against a green background, detailing its extensive branching hierarchy. Muscular branches are identified proximally to distally, including the pronator teres (PT), flexor carpi radialis (FCR), palmaris longus (PL), anterior interosseous nerve, flexor pollicis longus (FPL), pronator quadratus (PQ), flexor digitorum profundus (FDP), and flexor digitorum superficialis (FDS). Distal terminal branches are shown extending into the hand, including the sensitive palmar branch, thenar branches, and digital branches (1-3). The diagram includes a normalized distance scale, designating the epicondylar landmark at 24 cm (100%) and the styloid landmark at 0 cm (0%). This visual serves as a topographical guide for identifying nerve distribution during surgical procedures like electrode implantation or neurolysis.

This clinical photograph/anatomical diagram hybrid depicts the dorsal aspect of a human hand and distal forearm in a grayscale format. Superimposed on the anatomy is a schematic representation of the superficial branch of the radial nerve. A thick white line originates from the radial side of the forearm, traveling distally across the wrist. Upon reaching the dorsum of the hand, the line branches into multiple digital nerves that extend toward the thumb, index, middle, and ring fingers. A prominent black circular marker is placed on the first dorsal interosseous space (the web space between the thumb and index finger), identifying the Superficial Radial Neuropuncture Point (SRNP). The image illustrates the neuroanatomical basis for specific acupuncture or electroacupuncture sites, emphasizing the relationship between traditional medicine points and peripheral nerve distribution. This visual is intended for healthcare professionals or students studying neuroanatomy, physical medicine, or integrative pain management protocols.

Anatomical diagram and clinical photograph overlaying a human forearm to demonstrate the nerve transfer of the superficial branch of the radial nerve (SBRN) to the median nerve (MN). The visual illustrates the surgical anatomy and morphometric distances required for neurolysis and tension-free coaptation. Key landmarks identified from the lateral epicondyle of the humerus include the SBRN bifurcation (217 ± 7 mm), the radial styloid process (252 ± 6 mm), and the thenar branch takeoff (299 ± 7 mm). The original course of the SBRN is indicated in gray, while the post-transposition path toward the median nerve is shown as a dashed yellow line, with the coaptation site marked by a red dot. A brown highlighted area represents the pronator quadratus muscle. The diagram also specifies an 82 ± 6 mm segment required for interfascicular neurolysis between the median nerve and its thenar branch to facilitate the transfer. This educational material is designed for advanced orthopedic or plastic surgery training in peripheral nerve reconstruction.

This medical anatomical diagram illustrates a rare variation of the hand's neurovasculature, specifically the preligamentous course of the thenar motor branch (TMB) of the median nerve. The black-and-white line drawing shows the median nerve trunk passing deep to the transverse carpal ligament (TCL). In this variation, the thenar motor branch originates from the median nerve proximal to the carpal tunnel and courses superficially over the transverse carpal ligament before diving into the striated thenar musculature on the radial side of the palm. The illustration highlights critical surgical anatomy for procedures such as carpal tunnel release, where identifying the TMB's relationship to the TCL is essential to avoid iatrogenic injury. The diagram provides educational context for understanding anatomical deviations that do not strictly adhere to standard classifications like the Lanz system, specifically demonstrating an 'over the ligament' pathway rather than the typical subligamentous or transligamentous routes.

This clinical anatomical specimen photograph displays a superficial dissection of the distal forearm and wrist, focusing on the neurovascular relationships along the radial aspect. Key anatomical landmarks are identified with yellow labels: the radial styloid process is marked as 'O' (indicated by a white pin), the superficial branch of the radial nerve is labeled 'SB', and the cephalic vein is labeled 'V'. The image demonstrates the close proximity and crossover point of the cephalic vein and the sensory branches of the radial nerve as they course distally toward the dorsal hand. A metallic caliper and ruler are positioned alongside the specimen to provide a metric scale for morphometric measurements between the styloid process and nerve-vein intersections. This educational visual is designed to assist in understanding surgical anatomy for procedures such as cephalic vein cannulation or radial artery harvesting, where avoiding injury to the superficial branch of the radial nerve is critical.

This physiological waveform diagram displays a simultaneous recording of three cardiac parameters used for assessing cardiovascular hemodynamics. The top trace is an Electrocardiogram (ECG) showing standard QRS complexes representing ventricular depolarization. The middle trace is a Phonocardiogram (PCG) capturing acoustic vibrations of heart sounds, specifically the S1 and S2 sounds. The bottom trace is a Brachial Pulse Volume Waveform (bPVW) illustrating the peripheral arterial pressure pulse. Vertical markers indicate temporal relationships between these signals to calculate systolic time intervals. The 'QS2' interval is marked from the onset of the QRS complex on the ECG to the aortic component of the second heart sound on the PCG, representing the total electromechanical systolic interval. The 'bET' (Brachial Ejection Time) is delineated on the bPVW from the waveform foot to the dicrotic notch. An annotated formula shows the calculation of the Brachial Pre-ejection Period (bPEP) as the difference between QS2 and bET (bPEP = QS2 - bET). This diagram is an educational tool for understanding the non-invasive assessment of cardiac systolic function and arterial stiffness.

Summary : This figure illustrates the left atrial (LA) pressure-volume relationship during the cardiac cycle, showing both time-course traces and a pressure-volume loop, with key phases of atrial function annotated and correlated with the ECG. line plot and loop diagram: # Panel A: LA Pressure and Volume Traces • Top trace: LA Pressure (y-axis, arbitrary units) over time. • Middle trace: LA Volume (y-axis, arbitrary units) over time. • Bottom trace: ECG waveform for temporal reference. • X-axis: Cardiac cycle phases, with systole and diastole labeled; diastole further subdivided into E, D, and A phases. • Five phases are color-coded and numbered: – (1) Atrial filling (red) – (2) Passive emptying (green) – (3) Diastasis (black) – (4) Active emptying (blue) – (5) Atrial relaxation (gray) • Vertical dashed lines demarcate transitions between phases. # Panel B: LA Pressure-Volume Loop • X-axis: LA Volume (arbitrary units). • Y-axis: LA Pressure (arbitrary units). • The loop is traced in a counterclockwise direction, with arrows indicating the sequence. • The same five phases (1–5) are color-coded as in Panel A. • The loop is divided into two segments: A-Loop (phases 1, 3, 4, 5) and V-Loop (phase 2). # Design Encodings : • Distinct colors for each phase (red, green, black, blue, gray). • Arrows on the loop indicate the direction of the cardiac cycle. • ECG trace provides timing reference for the pressure and volume changes. # Analysis : • The LA pressure and volume traces show cyclical changes corresponding to atrial filling, emptying, and relaxation. • The pressure-volume loop visually summarizes the dynamic relationship between LA pressure and volume, with distinct segments for passive and active phases. • The figure highlights the temporal coordination between atrial events and the ECG, emphasizing the mechanical and electrical coupling in the cardiac cycle.

An educational anatomical and physiological diagram illustrating the synchronous collection of multiple cardiovascular biosignals in a canine model. The left side features a lateral-view anatomical illustration of a canine, highlighting the skeletal system, the heart, and major peripheral arteries. Four distinct biosignal waveforms are displayed on the right, with arrows tracing each to its anatomical point of acquisition: 1) LVBP (Left Ventricular Blood Pressure) signal, showing a rhythmic pressure waveform originating from the heart. 2) PPG (Photoplethysmogram) signal, a pulsatile volume waveform traced to the femoral artery. 3) ECG (Electrocardiogram) signal, showing characteristic P-QRS-T complexes with a prominent R-wave, traced to the forelimbs (Lead I configuration). 4) PCG (Phonocardiogram) signal, depicting high-frequency oscillations representing heart sounds, recorded from the cardiac apex. The diagram demonstrates the integration of invasive and non-invasive hemodynamic monitoring, useful for teaching comparative physiology and cardiovascular signal processing.

Summary : This figure illustrates the left atrial (LA) pressure-volume relationship during the cardiac cycle, showing both time-course traces and a pressure-volume loop, with key phases of atrial function annotated and correlated with the ECG. line plot and loop diagram: # Panel A: LA Pressure and Volume Traces • Top trace: LA Pressure (y-axis, arbitrary units) over time. • Middle trace: LA Volume (y-axis, arbitrary units) over time. • Bottom trace: ECG waveform for temporal reference. • X-axis: Cardiac cycle phases, with systole and diastole labeled; diastole further subdivided into E, D, and A phases. • Five phases are color-coded and numbered: – (1) Atrial filling (red) – (2) Passive emptying (green) – (3) Diastasis (black) – (4) Active emptying (blue) – (5) Atrial relaxation (gray) • Vertical dashed lines demarcate transitions between phases. # Panel B: LA Pressure-Volume Loop • X-axis: LA Volume (arbitrary units). • Y-axis: LA Pressure (arbitrary units). • The loop is traced in a counterclockwise direction, with arrows indicating the sequence. • The same five phases (1–5) are color-coded as in Panel A. • The loop is divided into two segments: A-Loop (phases 1, 3, 4, 5) and V-Loop (phase 2). # Design Encodings : • Distinct colors for each phase (red, green, black, blue, gray). • Arrows on the loop indicate the direction of the cardiac cycle. • ECG trace provides timing reference for the pressure and volume changes. # Analysis : • The LA pressure and volume traces show cyclical changes corresponding to atrial filling, emptying, and relaxation. • The pressure-volume loop visually summarizes the dynamic relationship between LA pressure and volume, with distinct segments for passive and active phases. • The figure highlights the temporal coordination between atrial events and the ECG, emphasizing the mechanical and electrical coupling in the cardiac cycle.

This medical illustration combines a physiological graph and echocardiographic frames to depict left atrial (LA) phasic function during the cardiac cycle. The top panel presents a color-coded volume-over-time curve divided into three functional phases: Reservoir (pink), representing LA filling during ventricular systole; Conduit (tan), showing early passive LA emptying after mitral valve opening; and Pump (blue), indicating active atrial contraction during late diastole. Vertical red arrows quantify volume changes for each phase. The middle panel features six apical four-chamber view echocardiograms with manual endocardial tracing (yellow outlines) of the LA. These frames are synchronized to clinical events: mitral valve closure (minimum LA volume), aortic valve closure (maximum LA volume), and mitral valve opening. Red arrows on the ultrasound images highlight the status of the mitral and aortic valves. The bottom panel displays a synchronized electrocardiogram (ECG) trace. This educational visual demonstrates how automated Vector Velocity Imaging (VVI) software tracks atrial mechanics and volumes to assess diastolic function in patients.

Summary : This figure shows a pressure–volume loop for the left ventricle, illustrating how ventricular volume and pressure change during the cardiac cycle, with key phases and valve events annotated. The isovolumetric relaxation and contraction periods are highlighted, and systolic/diastolic blood pressures are marked. pressure–volume loop diagram: # Title & Axes : • No explicit title on the figure, but the legend describes it as a "Pressure–volume loop demonstrating changes in ventricular volume during filling and ejection with corresponding changes in intracavity pressure." • X-axis: "Left ventricular volume (mL)" with tick marks at 0, 20, 40, 60, 80, 100, 120, 140, 160. • Y-axis: "Left ventricular pressure (mmHg)" with tick marks at 0, 20, 40, 60, 80, 100, 120, 140. • Additional axis labels: "Left ventricular end-diastolic pressure" (blue, left), "End-diastolic volume" (blue, bottom right), "Stroke volume" (black, bottom center). # Phases & Events : • Isovolumetric relaxation: vertical line at low volume, pressure drops, labeled. • Diastolic filling: horizontal line at low pressure, volume increases, labeled. • Isovolumetric contraction: vertical line at high volume, pressure rises, labeled. • Ventricular ejection: curved line, volume decreases as pressure peaks and falls, labeled. • Valve events: – Mitral valve opens (bottom left corner, low pressure/volume). – Mitral valve closes (bottom right corner, high volume/low pressure). – Aortic valve opens (top right corner, high volume/high pressure). – Aortic valve closes (top left corner, low volume/high pressure). # Blood Pressure Markers : • Systolic BP: horizontal dashed blue line at ~120 mmHg. • Diastolic BP: horizontal dashed blue line at ~80 mmHg. # Design Encodings : • Black solid lines for the loop. • Blue dashed lines for blood pressure markers. • Blue text for end-diastolic volume/pressure. • Labeled arrows for direction of phases and valve events. # Analysis : • The loop traces the cardiac cycle, starting at low pressure/volume (end-systolic), filling during diastole, rising sharply during isovolumetric contraction, ejecting blood during ventricular ejection, and dropping pressure during isovolumetric relaxation. • Systolic and diastolic blood pressures are marked, showing the pressure range during ejection. • The width of the loop (horizontal distance) represents stroke volume. • The figure clearly distinguishes the four main phases and the timing of valve openings/closings, providing a comprehensive view of ventricular mechanics during a heartbeat.