Lymphoid Organs: Overview

00:01 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.

00:29 And we’re also going to look at the appendix and gut-associated lymphatic tissues.

00:35 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.

01:14 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.

01:28 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.

01:57 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.