Any of numerous nodes (collections of tissue) situated in the areas of underarm veins that receive lymphatic drainage (almost colorless fluid that travels through vessels and carries cells that help fight infection and disease) from the upper limb, pectoral girdle (bones supporting the front or upper parts of the body), and mammary gland (two half-moon-shaped glands on either side of the adult female chest, which make up the breast): Jenny's primary physician, Dr. Smith, tried to explain how the axillary glands function and how this might explain why she was having an abnormal feeling in her armpits.