Video Transcript
Endocrine glands secrete hormones
directly into the bloodstream. Using this information, which of
the following best describes endocrine glands? (A) Tubeless, (B) duct shaped, (C)
ductless.
To answer the question, we need to
recall what endocrine glands are and some of the unique features of endocrine
glands.
Endocrine glands are the component
parts that make up the endocrine system. Endocrine glands work like other
glands in the body. They are a specialized organ that
produces and secretes substances that have different functions. Most endocrine glands share a
similar structure, with blood vessels directly surrounding endocrine tissue or
cells. As you can see from their
structure, endocrine glands do not have tubes or ducts to deliver their
secretions. This is why they’re sometimes
called ductless glands.
Without ducts or tubes, the cells
of the endocrine glands secrete chemical messengers called hormones directly into
the bloodstream. Once the hormones are in the
bloodstream, they travel to their target organs where they can have an effect. Other glands within the body, like
exocrine glands, secrete their substances directly into a duct or tube. Once substances from the exocrine
glands are in the tubes or ducts, they travel to their target organs where they can
have an effect. So, endocrine glands, unlike other
glands in the body, do not have tubes or ducts to deliver their secretions.
After reviewing the differences
between endocrine and exocrine glands, we are now able to answer the question. Therefore, the best description of
the endocrine glands describes them as ductless.
