Group 6 - Lymphatic System

LESSON TITLE:
LYMPHATIC
SYSTEM AND
IMMUNITY
LYMPHATIC SYSTEM
-DEFINITION- -FUNCTIONS-
● a subsystem of the circulatory system in the ● Fluid balance in
vertebrate body that consists of a complex
tissues
network of vessels, tissues, and organs.
● Lipid absorption
● helps maintain fluid balance in the body by
from small
collecting excess fluid and particulate matter
from tissues and depositing them in the intestines
bloodstream. ● Defense against
● It also helps defend the body against infection pathogens
by supplying disease-fighting cells called
lymphocytes
LYMPHATIC CIRCULATION
PARTS OF THE LYMPHATIC SYSTEM
LYMPH
● a collection of the extra fluid that
drains from cells and tissues (that
is not reabsorbed into the
capillaries) plus other substances.
● Lymph also transports infection-
fighting white blood cells
(lymphocytes).
LYMPHATIC TISSUE
● are organized structures that support immune responses.
● characterized by housing many lymphocytes & other defense cells
LYMPH CAPILLARIES
● tiny, thin-walled microvessels
located in the spaces between
cells (except in the central
nervous system and non-
vascular tissues) which serve to
drain and process extracellular
fluid.
LYMPHATIC VESSELS
● Lymphatic vessels are the network of capillaries

(microvessels) and a large network of tubes located
throughout your body that transport lymph away from
tissues.
SPLEEN
This largest lymphatic
organ is located on your
left side under your ribs
and above your stomach.
The spleen filters and
stores blood and produces
white blood cells that fight
infection or disease.
LYMPH NODES
Lymph nodes are bean-shaped
glands that monitor and
cleanse the lymph as it filters
through them. The nodes filter
out the damaged cells and
cancer cells. These lymph
nodes also produce and store
lymphocytes and other immune
system cells that attack and
destroy bacteria and other
harmful substances in the fluid.
THYMUS
This organ is located in the upper

chest beneath the breast bone. It
matures a specific type of white
blood cell that fights off foreign
organisms.
TONSILS AND ANDENOID

These lymphoid organs trap
pathogens from the food you
eat and the air you breathe.
They are your body’s first line
of defense against foreign
invaders.
BONE MARROW
This is the soft, spongy tissue in

the center of certain bones, such
as the hip bone and breastbone.
White blood cells, red blood cells,
and platelets are made in the bone
marrow.
IMMUNE SYSTEM
The immune system includes a

variety of defenses against viruses,
bacteria, fungal infections, and
parasites (such as thread worms).
The lymphatic system is part of the
broader Immune System.
IMMUNE RESPONSES
The defensive strategies, called

immunity, utilize lymphocytes.
These are specialized white blood
cells that develop in parts of the
lymphatic system, including red
bone marrow and the thymus.
Among these cells are T and B
lymphocytes, which are located
within lymph nodes and other
lymphatic tissues.
What are the main organs of the lymphatic system?
● The lymphatic system is commonly divided into the primary lymphoid
organs, which are the sites of B and T cell maturation, and the secondary
lymphoid organs, in which further differentiation of lymphocytes occurs.
● Primary lymphoid organs include the thymus, bone marrow, and fetal liver
● In humans the thymus and bone marrow are the key players in immune
function.
● All lymphocytes derived from stem cells in the bone marrow. Stem cells
destined to become B cells remain in the bone marrow as they mature, while
prospective T cells migrate to the thymus to undergo further growth.
● Mature B and T cells exit the primary lymphoid organs and are transported
via the bloodstream to the secondary lymphoid organs, where they become
activated by contact with foreign materials, or antigens.
What is the role of the lymphatic system in immunity?
In addition to serving as a drainage network, the lymphatic system

helps protect the body against infection by producing white blood
cells called lymphocytes, which help rid the body of disease-
causing microorganisms. The organs and tissues of the lymphatic
system are the major sites of production, differentiation, and
proliferation of two types of lymphocytes—the T lymphocytes and
B lymphocytes, also called T cells and B cells, respectively.
Although lymphocytes are distributed throughout the body, it is
within the lymphatic system that they are most likely to encounter
foreign microorganisms.
What is the role of the lymphatic system in disease?
The importance of the primary lymphoid organs is demonstrated

by its involvement in autoimmune disease. Two autoimmune
diseases, DiGeorge syndrome and Nezelof disease, result in the
failure of the thymus to develop and in the subsequent reduction
in T cell numbers, and removal of the bursa from chickens results
in a decrease in B cell counts. The destruction of bone marrow
also has devastating effects on the immune system, not only
because of its role as the site of B cell development but also
because it is the source of the stem cells that are the precursors
for lymphocyte differentiation.

Group 6 - Lymphatic System

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LESSON TITLE:

● Lymphatic vessels are the network of capillaries

This organ is located in the upper

TONSILS AND ANDENOID

This is the soft, spongy tissue in

The immune system includes a

The defensive strategies, called

In addition to serving as a drainage network, the lymphatic system

The importance of the primary lymphoid organs is demonstrated

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