Please can anyone help me out in this whole definition actually I can't understand it

Capillaries are tiny branched blood vessels that joins the arteries to the veins

Explanation:

Capillaries are found in the junctions between arteries and veins in the tissues.

They have the following functions:

- They have tiny walls and are tiny enough to penetrate to all parts of the body

- The thin walls help them diffuse oxygen, nutrients and waste products between cells and the blood.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.