caption: an analogy for the key concept
exif: {"Image DocumentName": "KEY CONCEPTAll physiological functions are performed by specific anatomical structures.", "Image ImageDescription": "These functions follow standard physical and mechanical principles.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}