This is a macroscopic gross pathology photograph of the scrotal contents from a 25-year-old male with acute epididymo-orchitis in the setting of suspected testicular torsion. The specimen demonstrates destruction of the epididymal architecture with extensive inflammatory changes and partial involvement of the adjacent testicular parenchyma. The epididymis is irregular and disrupted, with creamy white exudate and pale tan to yellowish areas representing inflammatory tissue and early necrosis. The testicular surface shows uneven contour and focal inflammatory involvement; surrounding tunica and vascular structures may be congested. A 1 cm scale bar provides reference for lesion size. The overall appearance is that of an intense infectious/inflammatory process rather than isolated torsion, although torsion could be clinically suspected preoperatively. Such gross findings reinforce the diagnostic challenge of acute scrotal pain, where epididymo-orchitis can mimic torsion and lead to urgent surgical exploration. This image is valuable for medical education, urology training, and pathology teaching as a representative example of acute epididymo-orchitis with epididymal destruction and partial testicular involvement. Keywords: epididymitis, orchitis, acute inflammation, scrotal infection, gross pathology, pathology education, differential diagnosis, testicular torsion mimic, Pathorama.ch, 25-year-old male. These features are typical of acute inflammatory epididymal and testicular involvement.

Two color Doppler ultrasound images (A and B) of the scrotal contents demonstrating findings consistent with epididymo-orchitis. Image A displays the epididymis, which appears enlarged and heterogeneous with an irregular echotexture. The color Doppler overlay reveals focal hypervascularity (hyperemia), indicated by increased red and blue signals within the epididymal tissue. Image B shows the testis, which is similarly enlarged and heterogeneous. The Doppler study in B demonstrates diffuse, intense hypervascularity throughout the testicular parenchyma, often referred to as a 'thyroid storm' or 'inferno' sign in the clinical context of orchitis. These findings illustrate the standard diagnostic radiological approach for differentiating inflammatory conditions from testicular torsion; the presence of increased blood flow is characteristic of infectious or inflammatory processes like epididymitis and orchitis, whereas absent or reduced flow would suggest torsion. The imaging is relevant for urological and emergency medicine education regarding acute scrotum evaluation.

This diagnostic ultrasound display consists of two panels illustrating the clinical features of acute epididymo-orchitis in a 45-year-old male. Panel (a) is a transverse grayscale ultrasound of the scrotum providing a side-by-side comparison of the testes. The right testis (RT) is markedly enlarged and demonstrates a diffuse hypoechoic echotexture compared to the normal left testis (LT). Additionally, the overlying right scrotal skin is significantly thickened, indicated by an asterisk. Panel (b) shows a longitudinal color Doppler ultrasound (CDUS) of the right hemiscrotum. This image reveals prominent hypervascularity within both the testis and the adjacent epididymis, characterized by dense red and blue signals representing increased blood flow (hyperemia). These visual findings—testicular enlargement, decreased echogenicity, skin thickening, and hyperperfusion—are classic diagnostic indicators for infectious or inflammatory processes of the scrotum, distinguishing epididymo-orchitis from testicular torsion where flow would be absent.

This contrast-enhanced CT study consists of coronal (a) and axial (b) sections of the pelvic and scrotal region, demonstrating findings characteristic of acute epididymo-orchitis with complications. The imaging reveals significant enlargement and intense, heterogeneous contrast enhancement of the left testis (arrow) and left epididymis (arrowhead), indicating severe inflammation and hyperemia. Associated features include marked thickening of the scrotal wall and a reactive hydrocele (asterisk), seen as a hypoattenuating fluid collection surrounding the testicular structures. In the axial view (b), a distinct focal area of non-enhancement with peripheral rim enhancement is visible in close contact with the testis and hydrocele, representing an abscess formation. These radiological findings are critical for diagnosing complicated intrascrotal infections and differentiating them from simple epididymitis or testicular torsion. The image serves as an educational resource for identifying secondary signs of infection such as abscess development and reactive fluid accumulation within the tunica vaginalis.

A multi-panel line graph illustrating the physiological mechanics of an in vitro cardiac loading device (CLD) used to simulate ventricular pressure-volume relationships. The visualization consists of four vertically aligned time-series plots depicting a cyclical cardiac simulator test. The top panel shows heart chamber pressure oscillating between 0 and 100 mmHg. The second panel displays ventricular balloon (VB) pressure, reaching peaks of approximately 80 mmHg. The third panel tracks reservoir balloon (RB) pressure, which fluctuates between 10 and 14 mmHg. The bottom panel indicates the status of an electronic check valve (ECV) as a binary voltage (0V for closed, 5V for open). Vertical dashed lines (labeled 1, 2, and 3) correlate specific phases: (1) ECV opening when VB pressure exceeds afterload, leading to VB emptying and RB filling; (2) VB refilling when VB pressure drops below RB pressure; and (3) ECV closure upon completion of refilling. This diagram is utilized in cardiovascular physiology research to validate cardiac cycle simulation for isolated heart preparations.

This composite educational graphic details the pathophysiology of myocardial perfusion and coronary hemodynamics. Panel A features a pathophysiology diagram illustrating the extravascular forces and intraluminal pressures affecting the myocardial layers during the cardiac cycle. It compares diastole and systole, highlighting the differences in intramural pressure (PINTRAMURAL), left ventricular lumen pressure (PLUMEN), and pericardial space pressure (PPERICARDIUM). The diagram shows the subendocardial plexus and epicardial artery, emphasizing greater subendocardial compression and reduced vascular volume during systole. Panel B presents a cardiac perfusion quantification map from a patient with aortic stenosis (AS). The map is organized in a grid: rows represent basal, mid, and apical short-axis slices of the left ventricle; columns demonstrate stress perfusion, rest perfusion, and myocardial perfusion reserve (MPR). The color-coded mapping shows regional perfusion distribution, with the MPR column specifically highlighting global limitations in perfusion reserve. This visual is designed for medical education focusing on cardiovascular hemodynamics, coronary microcirculation, and the physiological impact of valvular heart disease on myocardial blood flow.

Summary : This diagram illustrates the traditional coagulation cascade, detailing the sequence of events and factors involved in blood clotting via the intrinsic, extrinsic, and common pathways. flowchart: # Pathways : • Intrinsic pathway (green box): Initiated by factor XII, proceeds through XI, IX, and VIII, with activation steps indicated by "a" (e.g., XIIa, XIa, IXa). • Extrinsic pathway (red box): Initiated by tissue damage, which activates tissue factor (TF) and factor VIIa. • Common pathway (blue box): Both intrinsic and extrinsic pathways converge at factor X, leading to the activation of prothrombin to thrombin, which then converts fibrinogen to fibrin, forming a fibrin clot. # Nodes : • XII → XIIa (Intrinsic) • XI → XIa (Intrinsic) • IX → IXa (Intrinsic) • Ca²⁺, PT, V (Intrinsic, Common) • TF/VIIa (Extrinsic) • Tissue damage (Extrinsic) • X → Xa (Common) • Prothrombin → Thrombin (Common) • Fibrinogen → Fibrin (Common) • XIII (Common) • Fibrin clot (Common) # Connectors : • Arrows indicate the direction of activation or conversion between factors. • Intrinsic and extrinsic pathways both feed into the activation of factor X in the common pathway. • Ca²⁺ and PT, V are required cofactors at specific steps. # Layout : • Three main colored sections: green (intrinsic, top left), red (extrinsic, top right), blue (common, bottom). • Flow proceeds from top (initiation) to bottom (clot formation). • Arrows show sequential activation and convergence of pathways. # Analysis : • The diagram clearly separates the intrinsic and extrinsic initiation mechanisms, both converging on the common pathway at factor X. • The cascade is highly sequential, with each activated factor catalyzing the next step. • Calcium ions (Ca²⁺) and phospholipids (PT) are essential cofactors at multiple steps. • The final outcome is the formation of a stable fibrin clot, highlighting the coordinated nature of the coagulation process.

This medical schematic illustrates the physiological processes of hemostasis and fibrinolysis. Part A depicts the Coagulation Cascade, divided into the Intrinsic, Extrinsic, and Common pathways. The Intrinsic pathway (purple) is triggered by internal damaged surfaces, activating Factor XII to XIIa, followed by XI and IX. The Extrinsic pathway (green) begins with endothelial tissue damage and Tissue Factor (TF), activating Factor VII to VIIa. Both pathways converge at the Common pathway (blue) starting with the activation of Factor X to Xa. This leads to the conversion of prothrombin (II) to thrombin (IIa), and fibrinogen (I) to fibrin (Ia), culminating in a stable fibrin clot stabilized by Factor XIIIa. Activated factors are denoted by an 'a' suffix. Part B illustrates Fibrinolysis, where tissue-type (t-PA) and urokinase-type (u-PA) plasminogen activators convert plasminogen to plasmin, which then degrades the fibrin network of the blood clot. Inhibitory regulators including PAI-1, PAI-2, and ̡2-antiplasmin are also shown. The diagram represents the structural breakdown of a clot containing platelets and red blood cells into fibrin degradation products.

A pathophysiology diagram illustrating the cellular mechanisms and signaling pathways of Type IVa and Type IVb hypersensitivity reactions. Panel A (Type IVa) shows an antigen-presenting cell (APC) interacting with a T helper cell (Th) via MHC class II and TCR. IL-12 signaling leads to Th1 differentiation. Th1 cells release IFN-gamma to activate macrophages, which secrete TNF-alpha, nitric oxide, and reactive oxygen species (ROS) resulting in cell damage. Th1 cells also release IL-2 for B cell recruitment and IgG1/IgG3 antibody secretion. Panel B (Type IVb) depicts Th2 differentiation mediated by IL-4. Th2 cells release IL-5 for eosinophil recruitment, contributing to inflammation and damage. They also produce IL-4 and IL-13 for B cell recruitment leading to IgE and IgG4 secretion, as well as IL-3, IL-4, and IL-10 for mast cell and basophil recruitment and degranulation. The diagram utilizes standard immunological symbols to demonstrate delayed-type hypersensitivity pathways relevant to conditions like contact dermatitis and allergic drug reactions.

This medical illustration presents the Paley classification system for fibular hemimelia, a congenital deficiency of the fibula. The diagram is organized by anatomical severity, featuring both anterior (AP) and lateral (LAT) views for each type. Type 1 shows a stable ankle with a nearly full-length fibula. Type 2 illustrates dynamic valgus instability where the distal fibular physis is proximal to the ankle joint line. Type 3 is characterized by fixed equino-valgus deformities and is subdivided: 3A (ankle type) showing distal tibial malorientation; 3B (subtalar type) involving subtalar coalition with (3B1) or without (3B2) a visible distal fibular remnant; and 3C (combined) featuring both tibial and subtalar malalignment. Type 4 depicts a fixed equino-varus deformity with subtalar coalition. Key visual markers include the mechanical axis of the tibia (red line), the orientation of the distal tibial physis, the presence/absence of the fibula, and the articulation of the talus and calcaneus. This orthopedic diagram serves as a clinical guideline for reconstructive surgical planning in pediatric lower limb deficiencies.

This pathophysiology diagram illustrates the structural integrity of the blood-brain barrier (BBB) and the impact of ischemia on endothelial junctions. The top panel shows a cerebral capillary containing erythrocytes, surrounded by endotheliocytes and astrocyte foot processes within the penumbra region, highlighting increased partial pressure of oxygen (PO2). A magnified comparative view demonstrates the intercellular junctional complex between endotheliocytes. On the left ('before' state), the intact BBB consists of gap junctions (Connexin), adherens junctions (E-cadherin), and tight junctions (JAM, Occludin, and Claudin) maintaining paracellular seal. The right panel depicts the 'ischemic' state, where the tight junction proteins Occludin and Claudin show visible fragmentation and loss of continuity, signifying increased BBB permeability and structural breakdown. This medical illustration is designed to explain the mechanisms of BBB disruption in acute ischemic stroke and the potential protective role of Normobaric Hyperoxia (NBHO) in slowing the degradation of tight junction proteins (TJP) and matrix metalloproteinase-9 induction.

A medical pathophysiology diagram illustrating the comparative structural and molecular anatomy of the Blood-Brain Barrier (BBB) and the Blood-Cerebrospinal Fluid Barrier (BCSFB). The central image shows a sagittal view of the human brain with callouts for each barrier. The BBB section depicts a non-fenestrated capillary lined by brain capillary endothelial cells, surrounded by pericytes and astrocyte endfeet. In contrast, the BCSFB section shows the choroid plexus (CP) epithelium as a monolayer of cuboidal cells overlying highly vascularized connective tissue containing fenestrated capillaries. Both barriers feature a detailed cellular view highlighting five key molecular hallmarks: (1) Tight junctions for paracellular restriction, (2) ABC transporters (efflux pumps using ATP), (3) SLC transporters for facilitated or active transport, (4) Metabolizing enzymes (e.g., CYP and GST) for chemical modification, and (5) Membrane receptors for endocytosis and transcytosis. This infographic serves as an educational tool for neurovascular physiology and pharmacology.

This medical illustration depicts the neural control of the lower urinary tract, specifically the micturition reflex and voluntary bladder control. It shows the hierarchical integration between the brain (primary motor cortex M1, prefrontal cortex, periaqueductal gray PAG, and pontine micturition center PMC) and the spinal cord. The diagram illustrates three distinct pathways: 1) The sympathetic pathway (red), originating from the T11-L2 intermediolateral cell column (IML) via the hypogastric nerve, releasing norepinephrine (NE) to inhibit the detrusor muscle (beta-3 receptors) and contract the bladder neck (alpha-1 receptors). 2) The parasympathetic pathway (blue), originating from the S2-S4 sacral parasympathetic nucleus (SPN) via the pelvic nerve, releasing acetylcholine (ACh) to contract the detrusor muscle (M3 receptors). 3) The somatic motor pathway (yellow), originating from Onuf's nucleus (S2-S4) via the pudendal nerve, releasing ACh to contract the external urethral sphincter (nicotinic receptors). This diagram serves as a pathophysiology and anatomical guide to neurogenic bladder and the physiological mechanisms of urination.

Summary : This figure illustrates the sites of dysfunction in the neural control of the lower urinary tract, the major aetiological factors contributing to these dysfunctions, and the resulting mechanisms of bladder dysfunction. It visually links anatomical/functional sites, causes, and pathophysiological outcomes. flowchart: # Sites of Dysfunction : • Brain circuits: Pontine micturition centre, Periaqueductal gray, Limbic system, Hypothalamus, Prefrontal cortex. • Efferent pathways: Sacral cord, Sacral nerves, Pelvic nerves, Postganglionic neurons. • Afferent pathways: Peripheral afferents, Anterolateral white column, Posterior column. • Detrusor muscle: Detrusor myocyte, Extracellular matrix. # Major Aetiological Factors : • Neurological disease or injury (affecting brain circuits, efferent, and afferent pathways). • Bladder outlet obstruction (affecting efferent and afferent pathways). • Diabetes mellitus (affecting afferent pathways and detrusor muscle). • Normative ageing (affecting all sites). # Mechanisms : • Failure of integration or processing (linked to brain circuits). • Impaired activation of detrusor (linked to efferent pathways). • Early termination of voiding reflex (linked to afferent pathways). • Loss of intrinsic contractility (linked to detrusor muscle). # Connectors : • Vertical arrows connect each site of dysfunction to its corresponding aetiological factors and mechanisms. • Some aetiological factors (e.g., neurological disease or injury, normative ageing) span multiple sites and mechanisms. # Layout : • Three main columns: Site of dysfunction (left), Major aetiological factors (center), Mechanisms (right). • Rows correspond to anatomical/functional levels from brain to bladder muscle. • Arrows indicate causal or contributory relationships across columns. # Analysis : • The diagram highlights that bladder dysfunction can arise from multiple neural and muscular sites, with overlapping aetiological factors such as neurological disease, outlet obstruction, diabetes, and ageing. • Mechanisms of dysfunction are specific to the site affected, but some factors (e.g., ageing) can impact all levels. • The flowchart structure clarifies how different diseases or injuries can lead to specific bladder dysfunction mechanisms by affecting distinct anatomical pathways.

A composite panel of electrodiagnostic waveforms from a nerve conduction study (NCS) and F-wave analysis in a clinical setting. Panels A and B display sensory nerve conduction velocity (NCV) waveforms for the left and right sural nerves, respectively; Panel A shows a defined sensory nerve action potential (SNAP) while Panel B demonstrates significant dispersion and baseline instability. Panels C through F represent motor NCV studies of the left and right peroneal and tibial nerves, showing compound muscle action potentials (CMAPs) with markers for onset (O) and peak (P) at ankle, knee, and fibular head (B Fib) stimulation sites. Panels G through J display late response F-wave studies for the bilateral peroneal and tibial nerves. Notably, Panel G shows an absent or severely diminished F-wave response in the left peroneal nerve, while Panel J shows a highly irregular, high-amplitude waveform in the right tibial nerve. These findings are used to evaluate peripheral neuropathies, demyelinating conditions like Guillain-Barré Syndrome (GBS), or axonal injury.

This diagnostic image displays a nerve conduction study (NCS) of the right ulnar nerve, divided into sensory (A) and motor (B) components. Panel A shows the sensory nerve action potential (SNAP) recording at the wrist, characterized by a stimulus artifact followed by a flat baseline, indicating a lack of sensory response. Panel B illustrates motor nerve conduction tracings (CMAP) from five stimulation points: (i-iii) wrist, (iv) below the elbow, and (v) above the elbow. The motor tracings reveal significant pathology: traces i-iii show reduced distal amplitudes and prolonged distal latency, while traces iv and v demonstrate severe attenuation of the waveform and marked slowing of conduction velocity. This pattern of partial conduction block and reduced amplitude across the elbow is diagnostic of severe cubital tunnel syndrome or ulnar neuropathy at the elbow with mixed axonal and demyelinating features. Red vertical hash marks indicate latency and peak markers used for quantitative analysis in clinical neurophysiology.

This composite educational figure illustrates clinical imaging and immunological findings for a patient with a suspected primary immunodeficiency. Panel A is an axial chest CT scan showing the basal segments of the lungs. The image highlights cylindrical bronchiectasis in the left lower lobe, characterized by dilated, non-tapering bronchi presenting as tubular radiolucencies extending toward the periphery. Panel B displays a TCR repertoire analysis via spectratyping, comparing TCR specificities between the patient and a control group to assess T-cell receptor diversity. Panels C and D are bar graphs representing functional T-cell assays measured in counts per minute (CPM). Panel C compares T-cell proliferation in response to varying concentrations of Phytohaemagglutinin (PHA). Panel D shows proliferation in response to anti-CD3 stimulation, indicating a statistically significant reduction in the patient’s T-cell response compared to the control (p=0.01). Together, these panels correlate structural lung damage (bronchiectasis) with quantitative defects in cellular immunity, specifically impaired T-cell proliferative capacity, common in patients with panhypogammaglobulinaemia.

This diagnostic image displays multiparametric flow cytometry contour plots illustrating the immunophenotypic signature of Common Variable Immunodeficiency (CVID), specifically the 'AcT' cluster. The panel is organized into three rows: (A) Initial gating strategy for lymphocytes, CD19+ B cells, and CD3+ T cells; (B) Healthy control reference; and (C) CVID AcT patient profile. Key diagnostic hallmarks highlighted in red boxes for the AcT patient include a significant expansion of CD21low B cells (CD21-APC vs CD38-Alexa 700) and a shift in CD4+ T cell differentiation. Specifically, the patient shows a depletion of naive T cells (CD27+CD45RA+) and an expansion of intermediate memory T cells (CD27-CD28+). Additional plots demonstrate increased expression of senescence and activation markers, such as CD279 (PD-1), CD57, and CD70, in the patient's CD4+ T cell compartment. This visual comparison emphasizes the 'immunophenotypic aging' and chronic activation characteristic of certain CVID subsets, facilitating clinical classification and pathophysiological study of primary immunodeficiencies.