Answer:
If there was no system of lymphatic vessels, there would be no drainage of excess fluid from the tissues and the lymphatic fluid would accumulate in the tissues, causing them to swell.
Explanation:
The lymphatic vessel is made up of tiny vessels that are closed at one end and can be found in the spaces in the cells, except the central nervous system and the non-vascular tissues.
The main function of the lymphatic vessel is to move lymph which is a fluid that contains infection-fighting white blood cells to every part of the body.
So, if there was no system of lymphatic vessels, and tissue fluid was moved directly back into the circulatory system throughout the body. the lymphatic fluid would accumulate in the tissues, causing them to swell.