Introductory level demo lecture prepared for Assiniboine College.

1. Immune System - Demo Lecture
Why are lymph nodes important?

2. Lymphatic System
 Collects tissue
fluids – Lymph
 Fluids may contain
foreign particles
(ie. bacteria,
viruses, toxins)
 Antigens
 These are filtered
out by lymph
nodes
http://www.healingdaily.com

3. What is a Lymph Node?

A lymphatic organ, about 1-2 cm in dia.,
filled with lymphocytes

Functions:

Filters lymph before it enters the venous
system

Promotes Interaction of antigens with
lymphocytes to initiate an immune response

4. Lymph Node

Structure:

Has many afferent
(incoming)
lymphatic vessels

Subdivided into
Cortex, Paracortex
Source:
http://www.niaid.nih.gov/topics/immuneS
and Medulla
ystem/Pages/structureImages.aspx

One efferent
(outgoing) lymphatic
vessel

5. What is a Lymphocyte?

White blood cell, which is part of the
acquired immune system

Allows immune system to learn to identify a
pathogen and produce a more efficient
response on subsequent exposure

B-Lymphocytes

Produce antibodies, which mark
pathogens for destruction

T-Lymphocytes

Directly attack and kill infected cells

6. Important:
Each lymphocyte only recognizes one
target molecule (antigen)

A single B-lymphocyte will only be activated by
and produce antibodies specific to only one
antigen

A single T-lymphocyte will recognize and
become activated by only one specific antigen

7. Localization

Not many Lymphocytes are found in the
bloodstream

Majority of Lymphocytes are collected in
lymphatic organs (like lymph nodes and
the spleen) and lymphatic tissues

8. So, how do we get our
Lymphocytes to come into contact
with their targets?

9. Lymph flow through the node

In through afferent
lymphatic vessels

Cortex

Paracortex

Medulla
Source:
http://www.niaid.nih.gov/topics/immuneS
ystem/Pages/structureImages.aspx

Out through the
efferent lymphatic
vessel

10. So, what happens then?
http://www.buzzle.com/articles/swollen-
lymph-nodes-in-neck-on-one-side.html