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The lymphatic system is a network of organs and vessels that help clear
the body of toxins and waste, it also helps protect the body from
infections and outside invaders such as harmful bacteria and viruses So
It is considered to be part of the immune system and circulatory system.
The main functions of the lymphatic system are :
● Production of immune cells and antibodies
● Removal of excess interstitial fluid
● Absorbing Fatty acids and removing cellular waste
, Organs of the lymphatic system
Thymus
Thymus is a gland organ of the lymphatic system, it is located in the
chest between the lungs behind the sternum just in front and above the
heart within the neck region
It is an asymmetrical flat shape with a lobular structure, the lobules are
comprised of series of follicles which have medullary and cortical
component
The thymus is responsible for making white blood cells the T
lymphocytes which are important to help fight diseases and destroy
infected or cancerous cells, these cells are so essential and often sent to
other parts of the body to help fight infections, it is mostly active in the
childhood and starts to shrink as we age.
Abnormal functions :
one of the most common diseases of the thymus is myasthenia gravis
Myasthenia gravis is a neuromuscular disease that causes weakness in
the muscles it occurs when the communication between the nerves and the
muscles is damaged which causes muscle weakness.
In normal conditions the nerves communicate with the muscles by
releasing Chemical messengers ( neurotransmitters ) that fit perfectly in the
receptor on the muscle cells. While In myasthenia gravis the immune
system antibodies attack the receptor sites with many receptors being
blocked or destroyed,the effect of the neurotransmitter is reduced the
muscles receive fewer nerve signals causing muscle weakness.
symptoms include voluntary muscle weakness , fatigue , trouble speaking ,
dropping of eyelids , double vision, difficulty breathing eating and walking.
The exact cause of myasthenia gravis is unclear but researchers believe
that the thymus triggers the antibodies that attack the receptors, in healthy
adults the thymus gland is small in size while in adults with myasthenia
gravis it is abnormally large in size some adults with myasthenia gravis
have tumors on the thymus gland ( thymomas )
, Currently there is no cure for myasthenia gravis , however there are
medications that helps with the symptoms which include :
● Pyridostigmine
usually a tablet which helps electrical signals travel between the muscles
and nerves and therefore can reduce muscle weakness, however the effect
only lasts a few hours so it needs to be taken multiple times a day. For
some individuals this is the only medicine they need to control their
symptoms.
side effects include: diarrhoea, muscle twitching , stomach pain, feeling
sick.
Those side effects can be controlled by taking other medicine alongside
pyridostigmine
● Steroids
If pyridostigmine does not help control myasthenia gravis, doctors may
prescribe steroid tablets, e.g. prednisolone. Steroids reduce the activity of
the immune system to stop it from attacking the communication system in
the muscles and nerves.
side effects include: mood swings , increased risk of getting infection ,
weight gain.
Bone marrow
Bone marrow is the spongy tissue inside the medullary cavities in the
bones, it contains immature cells, called stem cells which are cells that
develop into many different cell types. like muscle cells, red blood cells,
brain cells and other types of cells..