The mammalian pineal organ.
D000818:Animals; D001341:Autonomic Nervous System / Q000033:anatomy & histology; D005075:Biological Evolution; D003624:Darkness; D004702:Endocrine Glands / Q000502:physiology; D008027:Light; D008297:Male; D008322:Mammals; D008854:Microscopy, Electron; D010786:Photoreceptor Cells / Q000502:physiology; D010870:Pineal Gland / Q000033:anatomy & histology* / Q000166:cytology / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D051381:Rats; D013564:Sympathetic Nervous System / Q000033:anatomy & histology