Unit 8 Assignment B: Understand the impact of disorder on the physiology of the
lymphatic system and the associated corrective treatment.
The Lymphatic System
The lymphatic system is a secondary transport system, considered as the immune system of the body
due to its defence ability and the production of antibodies by regulating immune responses to harmful
micro-organisms and toxins that enter the body. In addition to this, the lymphatic system plays an
important role in lipid transport and maintaining a viable blood pressure, by absorbing fats from the gut
and extra fluids from all over the body. It consists of primary lymphoid organs such as bone marrow and
the thymus, which create special immune system cells called lymphocytes, also known as white blood
cells. The secondary lymphoid organs consist of vessels, lymph nodes, tonsils, and the spleen, which are
responsible for fighting and removing foreign invaders, and filtering blood or lymph. [2]
Spleen
The spleen is an important organ in the lymphatic system. It is located in the upper left part of the
abdomen, behind the stomach. It is the largest lymphoid organ and is similar in structure to a large
lymph node. The spleen is responsible for filtering blood and removing old or damaged (abnormal or
misshapen) red blood cells. Additionally, it stores platelets and white blood cells, which are important
components of the body's immune system. The spleen also plays a role in detecting and responding to
infections by producing antibodies and activating immune cells. It initiates immune response by B cells
and T cells to antigens in the bloodstream. It acts as a reservoir for blood, and in case of an emergency,
it can release stored blood cells into the bloodstream to help maintain blood pressure and oxygen levels.
It stores a small supply of healthy red blood cells and platelets for your body to use in an emergency. If
your bone marrow isn’t working properly, your spleen can also be a back-up site for making new blood
cells. If the spleen is damaged or removed, the body's ability to fight infections may be compromised,
and there may be an increased risk of developing certain types of infections.
[1]
Thymus
The thymus is an important gland in the lymphatic system that is located in the upper chest, behind the
sternum (breastbone), just above the heart. It plays a critical role in the development and maturation of
T-cells, which are a type of white blood cell that helps the body fight infections and cancer. The thymus
gland is particularly important in childhood and adolescence when the immune system is developing. As
T-cells mature, they learn to recognize and attack specific foreign substances (antigens) in the body,
such as bacteria, viruses, and cancer cells. The thymus is responsible for training these T-cells to
recognize and respond appropriately to these antigens. After they mature, they enter your bloodstream
and travel to lymph nodes and organs, where they help your immune system fight infection. As people
age, the thymus gland gradually shrinks and is replaced by fatty tissue. This can lead to a decrease in the
production of T-cells, which can make older adults more susceptible to infections and cancer. In some
medical conditions, such as autoimmune diseases, the thymus gland can become overactive and
produce too many T-cells, leading to an attack on the body's own tissues. In rare cases, a tumour may
develop in the thymus gland, which can cause a variety of symptoms depending on its location and size.
[2]
, Tonsils
The tonsils are a part of the lymphatic system and are located at the back of the throat. There are three
main sets of tonsils: the pharyngeal tonsils (also called adenoids), the palatine tonsils, and the lingual
tonsils. The tonsils act as a first line of defence against foreign invaders, such as bacteria and viruses,
that enter the body through the mouth and nose. They are composed of lymphoid tissue, which
contains white blood cells that help to identify and neutralize harmful substances. The tonsils work by
trapping these substances in their crevices and folds, and then the white blood cells in the tonsils are
activated to attack and destroy the invaders. The tonsils also produce antibodies to help protect the
body against future infections. The tonsils can become infected themselves, a condition known as
tonsillitis, which can cause symptoms such as sore throat, difficulty swallowing, and fever. In some
cases, recurrent tonsillitis may require surgical removal of the tonsils, a procedure called a
tonsillectomy. [3]
Lymph Glands
Lymph glands, also known as lymph nodes, are small, bean-shaped structures that are part of the
lymphatic system. They are found throughout the body, but are most concentrated in the neck, armpits,
chest, abdomen, and groin. Lymph nodes filter lymph, a clear fluid that circulates through the lymphatic
system and carries white blood cells and other immune cells. Lymph nodes contain immune cells, such
as lymphocytes and macrophages, which detect and respond to foreign substances, such as bacteria,
viruses, and cancer cells. When an infection or injury occurs in a specific area of the body, the immune
cells in nearby lymph nodes become activated and increase in number, causing the lymph nodes to
become swollen and tender. This is a sign that the immune system is responding to the infection or
injury and is working to fight it off. In some cases, lymph nodes can become enlarged due to cancer or
other conditions. This can indicate the presence of abnormal cells or inflammation in the body and may
require further evaluation and treatment. Overall, lymph nodes play an important role in the body's
immune system by filtering and detecting foreign substances and are a key component in the body's
defence against infections and diseases. [4]
Lymph vessels and Valves
A network of lymph vessels connects the lymph nodes together, in which lymph fluid flows through.
These lymph vessels connect to a group of lymph nodes, which act as a filter. They trap or destroy
anything harmful that the body does not need. Some vessels are just under the skin, so breaking the skin
can easily damage them. Lymph fluid travels through the lymph vessels and drains into the bloodstream.
Lymph vessels are lined by endothelial cells and have a thin layer of smooth muscles that bind the lymph
vessels to the surrounding tissue. One of the main structural features of lymph vessels is their valves,
which prevent the backflow of lymph allowing it to flow forwards smoothly. When the pressure of
lymph fluid increase, as volume decreases from smooth muscle contraction, the fluid will be pushed
through the valve (opening it) into the next chamber of the vessel (called a lymphangion). Without
valves, the lymphatic system would be unable to function without a central pump. Smooth muscle
contractions only cause small changes in pressure and volume within the lumen of the lymph vessels, so
the fluid would just move backwards when the pressure dropped. [5,6]
Lymph Nodes