List of anatomical isthmi
# List of anatomical isthmi

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
