Bursa.
pericardial cavity
Those sac-like structures are called bursae. They contain a small amount of fluid to help reduce friction and provide cushioning between tissues such as muscles, tendons, and bones.
I this its the following: Bursae - located between skin and bones, tendons and bones, muscles and bones, or ligaments and bones - Main function: reduce friction between joints Joint Capsule - surrounds a synovial joint and encloses the synovial cavity - Main function: unite the articulating bones and reduce friction via production of synovial fluid
This is likely describing a mild bulging of the discs at the c4-c5 and c5-c6 levels in the cervical spine, which is pushing slightly backward into the space occupied by the thecal sac, a membrane that surrounds the spinal cord and nerve roots. This bulging may be causing indentation or slight compression on the thecal sac, but the extent of nerve compression would need to be assessed clinically for further evaluation.
The pericardium is a protective sac surrounding the heart that helps to keep it in place within the chest cavity. It does not actively move on its own.
Bursa
Bursa
The presence of a sac containing fluid (such as a cyst) can increase friction in the surrounding tissues due to its physical presence, leading to discomfort or pain. The movement of the sac against nearby structures can also generate friction and further exacerbate symptoms.
Friction around the heart and possible damage.
The Amniotic Sac is the sac that contains the baby.
Sac fungi get their name because of their asexual spore production, they produce their spores in pod/sac-like structures called asci.
pericardial cavity
Those sac-like structures are called bursae. They contain a small amount of fluid to help reduce friction and provide cushioning between tissues such as muscles, tendons, and bones.
The double-walled membranous sac that encloses the heart is called the pericardium. It consists of two layers: the outer fibrous pericardium, which provides protection and anchors the heart, and the inner serous pericardium, which produces a lubricating fluid that reduces friction as the heart beats. This structure plays a crucial role in maintaining the heart's position and function within the thoracic cavity.
Vaginal sac. Vagina means sheath.
A bursa is a sac filled with fluid to protect the tendons (plural bursae).A bursa is an expansion of synovial membrane that is found at sites of potential friction, ie. between your Achilles tendon and your calcaneus (heel bone).Bursae are lubricated on their inner walls by synovial fluid. By rolling between two structures, bursae keep friction to a minimum and prevent damage.
The pericardium surrounds the heart like a protective sac. It contains fluid that decreases friction.