Rolandic Anatomy
Sphincter Pupillae
AI-powered interactive muscular anatomy for medical and surgical education
The muscle that constricts the pupil. It is controlled by the "Parasympathetic" nervous system; if the 3rd Cranial Nerve is compressed (from a brain bleed), this muscle fails, and the pupil will be "Fixed and Dilated."
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Educational content only. Not medical advice. For clinical decisions, consult authoritative sources and qualified clinicians.