Endocrine system in vertebrates consists of endocrine glands. Endocrine glands do not have ducts thus, they are also called as ductless glands. The glands which secretes enzymes are glands with duct, called exocrine glands. Therefore, the hormones secreted from endocrine glands are directly poured into the blood for the action on target organs. Examples of endocrine glands are pituitary gland, thyroid gland, adrenal gland.
There are four main categories of anesthesia used during surgery and other procedures: general anesthesia, regional anesthesia, sedation (sometimes called "monitored anesthesia care"), and local anesthesia.
