sac in which the fetus develops in amniotes
Saccule is the medical term meaning small sac.
Pericarditis is inflammation of the sac around the heart.
Amnion is the membrane that covers the embryo. Chorion is the membrane that covers the amnion, the yolk sac, and the allantois. The space delimited by the chorion and the amnion is called amniotic cavity and it is filled with aminiotic fluid. The amniotic cavity has the functions of preventing desiccation of the embryo and of protecting it against mechanical shocks.
Herniectomy
Bursitisbursitis
Bursitis
Black Hawk
Cryptoorchidism
A cyst is a closed sac containing fluid or semisolid material. An abscess is another type of closed sac containing infectious material.
A dead end street ( the end of a bag)
Pericardial effusion.
It is called an Aneurysm