Musculoskeletal / VISUAL EXPLAINER
How Can Smooth Muscle Pull Without Sarcomeres?
Smooth muscle uses actin and myosin without repeated sarcomeres. Internal dense bodies and membrane-associated attachments connect filaments into a force-transmitting network rather than the regular banded arrangement of skeletal muscle.
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What the illustration shows
English anatomy poster on a deep navy background with cyan depth and gold headings. Title asks how smooth muscle pulls without sarcomeres. A cutaway spindle-shaped peach cell contains one central purple nucleus, cyan actin-containing filaments, coral myosin elements, gold internal dense bodies and gold membrane attachments. Silver supporting filaments cross the conceptual internal network around the nucleus. Leaders identify the cell, nucleus, actin-containing filaments, dense body, myosin and membrane attachment. Two lower enlargements show filament anchorage at an internal dense body and filaments meeting a plaque at the inner cell boundary. A statement says there are no repeated sarcomeres, but a connected force-transmitting network. A note states that the filament arrangement, colors and scales are illustrative. Gold AllHumanBody.com and the complete slogan appear above a small P0192 AI-assisted anatomy-education label. No planet imagery is present in the selected version.
How to interpret this poster
- Network geometry, filament thickness, myosin-head pattern, dense-body shape and spacing are conceptual, not ultrastructure.
- No skeletal Z-line bands, troponin mechanism, organ-specific shortening or universal gap-junction pattern is implied.
- Background texture is not an additional identified structure; colors and scales are artificial.
- AI-assisted educational illustration; not physician certification, microscopy, a diagnosis or individualized medical advice.
- Fine annotations need enlargement; the full description provides an accessible text alternative.
- Display the full uncropped illustration; do not trim titles, legends or boundary annotations.
AI-assisted educational illustration, adapted into web-sized images without changing its composition. This is general education, not an individual diagnosis or treatment recommendation.
EVIDENCE / CONTEXT
Sources and what they support
- Human Protein Atlas: Smooth muscle ↗
Actin/intermediate-filament dense-body anchorage without Z-discs.
- Anatomy and Physiology 2e: 10.8 Smooth Muscle ↗
Contractile proteins and internal/membrane-associated force transmission; preserved direct text and production reread.