title: Ultrastructure of the abdominal air sac of the fowl.
mesh_terms: D000005:Abdomen; D000400:Air Sacs / Q000648:ultrastructure*; D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002645:Chickens / Q000033:anatomy & histology*; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D004847:Epithelial Cells; D004848:Epithelium / Q000648:ultrastructure; D005347:Fibroblasts / Q000648:ultrastructure; D008854:Microscopy, Electron