1. Fill in the gaps in the sentences below using the words in the list.
target; blood system; ducts; hormones
a. Endocrine glands release their secretions directly into the blood. In other words they have no ...................
b. Endocrine glands secrete chemicals called ....................
c. Hormones are transported from the endocrine glands to all parts of the body by the ..............................
d. Although hormones are carried throughout the body they only affect specific ......................... organs and tissues