The lymphatic system contains lymphoid organs
and tissues. And the job of these organs is
to mount responses against any invading pathogens.
So I’m going to talk about the lymphoid
organs throughout this lecture. And hopefully
at the end of this lecture, I’d like you
to understand first of all a lymphatic nodule,
what its structure is, and what it resembles.
And we’re also going to look at the appendix
and gut-associated lymphatic tissues.
You should also recall how lymph is produced and
how lymph flows through lymph nodes and the
structure to the lymph node. Lymph nodes are
designed for detecting antigens. So we’ll
go through the structure of various components
of the lymph node. We will then move on to
look at the thymus. And at the end of this lecture,
you should have a thorough understanding
of the structure and function of the thymus.
And lastly, we’re going to look not just
to the lymph node, but we’re going to look
at the spleen as well, a very similar organ.
But you’ll appreciate that lymph node filters
lymph and the spleen filters blood. You should
know those differences, and also the structural
differences to allow those two different roles.
The function of the whole lymphatic system,
as I mentioned at the start of this lecture,
was to monitor all parts of the body, particularly
mucosal surfaces, mucosal surfaces that are
exposed to the exterior of the body, for instance,
the respiratory system and the gut. And to
monitor those surfaces and connective tissue
spaces, and detect invading antigens.
And once they're detected, they’d respond to them
by then alerting the lymphoid organs and cells
within each of those organs but its specialized
to act against certain antigens.