Spinal
When surgery is performed to remove a ruptured disc, the incision will be made in the back. Depending on where the ruptured disc is located, the incision can be in the upper back towards the neck, or the lower back near the tailbone.
The spinal cavity is involved in lumbar surgery.
The thoracic cavity.
this is a surgery involving the chest/thorax.
Thoracic cavity
Abdominopelvic
The thoracic cavity is used in order to perform CABG (coronary artery bypass graft) surgery.
The organisms that are in your intestines are not normally pathogenic but can be if they get into the wrong places such as your urinary tract or inside your body cavity if you have a ruptured appendix.
White gums are a sign of internal bleeding. If his spleen ruptured he might have bled to death so quickly that there was no time to react to save him. The swelling might be from the blood filling his body cavity, which would have also drawn blood away from his ears. The things you describe are normal for a ruptured spleen, but only the vet can tell you the cause of that.
A lobectomy is the name of the surgery to remove the entire lobe of a cancerous lung. This is one of the treatments for non-small cell lung cancer.
A coronary bypass surgery is one in which the surgeon uses vessels taken from other parts of the body to create new passages for blood to flow in and out of the heart due to blockages of the usual passages. This surgery is performed in the thoracic cavity.
abdominal cavity