List of anatomical isthmi explained

In anatomy, isthmus refers to a constriction between organs. This is a list of anatomical isthmi:

• Aortic isthmus, section of the aortic arch
• Cavo-tricuspid isthmus of the right atrium of the heart, a body of fibrous tissue in the lower atrium between the inferior vena cava, and the tricuspid valve
• Isthmus, the ear side of the eustachian tube
• Isthmus, narrowed part between the trunk and the splenium of the corpus callosum
• Isthmus, formation of the shell membrane in birds oviduct's
• Isthmus lobe, lobe in the prostate
• Isthmus of cingulate gyrus
• Isthmus of fauces, opening at the back of the mouth into the throat
• Isthmus organizer, secondary organizer region at the junction of the midbrain and metencephalon
• Isthmus tubae uterinae, links the fallopian tube to the uterus
• Kronig isthmus, band of resonance representing the apex of lung
• Thyroid isthmus, thin band of tissue connecting some of the lobes that make up the thyroid
• Uterine isthmus, inferior-posterior part of uterus