title: Systems of life. No 136. Senior systems. 1. Ageing.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D000818:Animals; D005075:Biological Evolution; D001823:Body Composition; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D005260:Female; D006262:Health; D006736:Horses; D006801:Humans; D007223:Infant; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D051381:Rats