Transcript Powerpoint.ppt

THE LYMPHATIC SYSTEM
Immunity
Fluid balance
Drainage of toxins and waste
products
THE SYSTEM
• The anatomy consists of:
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vessels like veins ,
drainage ducts ,
capillaries ,
specific organs with definite
capsules Eg spleen and
nodes.
There are also areas where
lymphatic tissue and cells are
found in groups such as the
Peyers patches in the small
intestines
The cells of the system are our
defence , leucocytes and
lymphocytes of many different
types .
The anatomy of this system includes
Primary organs :
Bone Marrow
Thymus
Secondary organs
Spleen
Lymph nodes
MALT(mucosal associated
lymphatic tissue )
The appendix
The tonsils
The adenoids
Peyers patches
Lymphatic vessels
which are like veins with valves
Capillaries which begin as
blind ended vessels.
Larger lymph vessels
Ducts and Trunks
Thoracic duct
Right lymphatic duct
Inguinal trunk
Collecting points
Cysterna chyli
The Thymus
The thymus is entirely
formed from lymphatic
tissue, it is extremely active
up until adolescence and
then it is thought to atrophy
It does however remain
active .
The thymus is the site of maturation
for T Cells.
THE SPLEEN
The spleen is entirely formed from Lymphatic tissue,
it contains both red and white blood cells which are
found in the red and white pulp which forms the
organ . The spleen breaks down old red and white
blood cells and stores blood like a resrvoire. It works
with the liver in break down of red blood cells and in
foetal blood production .
Lymphocytes
Lymphocytes are created in the bone marrow from where they travel
into the blood stream and to other organs and areas of the system .
Some cells are differentiated and fully matured when they leave the
bone these are known as B Cells and large lymphocytes . Others are
not and will mature either in the blood stream or in specific areas in
the system .
They include monocytes and macrophage capable of phogocytosis,
plus lymphocytes which mature in the thymus; when these cells
mature they are called T cells and perform the most important job of
orchestrating the immune response.
Blood travels around the body to and from the tissues delivering nutrients
and removing waste . Whereas whole blood cannot leave the blood
capillaries , the things it carries can and do .
They can be carried in interstitial fluid , this fluid bathes the tissues
delivering oxygen and food . It also collects carbon dioxide and other waste
products . Following the completion of this work it is picked up by lymphatic
capillaries , passing through their porous walls where the pressure is lower
than in the blood capillaries .
Lymph passes through vessels , is
filtered by the lymph nodes and
eventually passes into the drainage
ducts back to the venous system via the
subclavian veins at the base of the neck
close to the clavicles.
Known as the biological filters of
the system ;Lymph from all small
and medium vessels passes
through them . They are placed
strategically around the body at
both deep and superficial levels.
Each node is formed by lymphatic
tissue ,encapsulated by a white
fibrous tissue outer coating .
They vary in size, many are
described as coffee bean size and
shape. They have an outer cortex
and an inner medulla which is
divided up by trabeculae into
germinal centres with drainage
sinuses.
The nodes contain many B cells ,
T cells and macrophage.
Lymph enters the node through
Afferent vessels and leaves
through Efferent vessels.
Lymph Nodes
Positions of Superficial nodes
Drainage
areas.
Thoracic duct
Supratrochlear
There are
many deep
nodes
throughout the
pelvic,
abdominal and
thoracic
cavities .
Axillary
Cysterna chyli
Inguinal
Popliteal
The lymph from lower
nodes drains into the
cysterna chyli at the
level of the 1st lumbar
vertabrae, from there
it travels up the
thoracic duct and into
the subclavian veins .
Immunity
There are a number of ways of looking at this ; perhaps a simple way is to say
that all immunity is acquired , some naturally and passively via our mother’s
antibodies and some more actively ,which we build through subsequent
encounters with germs in our lives .
Artificially acquired immunity we get through vaccination.
Immunity falls into 2 groups ; Both B and T cells develop into specific types of
defence cells in response to specific germs
B cells which in the
presence of antigen
develop into :
1. Memory cells
2. Plasma cells which
produce antibodies
In response to antigen
Cellular immunity
T cells which in the
presence of antigen
develop into :
1.
Memory cells
2.
Helper cells
3.
Cytolitic cells and
4.
killers
Humeral immune cells deal
primarily with bacteria.
Cellular immune cells deal
with viruses.
Humeral immunity