Unit 8 – Lymphatic System
“As part of my college course, I have been offered the chance to participate in a work placement
programme. This has been organised in partnership with a national charity who work to engage
science students in aspirational work experience opportunities. The placement will allow me to
observe specialist laboratory work, practise a variety of scientific techniques and gain first-hand
experience of medical research into the role and function of the lymphatic system and disorders and
associated treatments. On completion of my one-month placement; I will be producing a portfolio of
evidence demonstrating the knowledge and understanding I have gained throughout the
programme. My portfolio will contain a detailed ‘patient case study’ related to the normal
functioning of the lymphatic system, impairment of normal function due to lymphatic diseases and
the treatments used to correct the effects of lymphatic diseases.” The report below will be looking
into the lymphatic system, focusing on the purpose of the lymphatic system, the functions of each
part, what a lymph is and how it is formed as well as identifying what lymphocytes are.
The lymphatic system is a vital part of the circulatory, immune, and metabolic systems that is often
overlooked. It is a part of the circulatory and immune systems, accordingly. The lymphatic system's
functions complement those of the bloodstream by regulating fluid balance in the body and filtering
pathogens from the blood. The lymphatic system is composed of: lymphatic fluid, lymphatic vessels,
lymphatic cells, and lymphatic organs. Lymphatic fluid is a protein-rich fluid that circulates in the
lymphatic system and envelops all tissues. It circulates 75-100 grams of protein per day in the
bloodstream. White blood cells, triglycerides, bacteria, cell debris, water, and protein are all found in
lymph. Its composition is similar to that of blood plasma. Interstitial fluid from the periphery is
reabsorbed by lymphatic vessels and returned to the intravascular space, preventing excess fluid
build-up in peripheral tissues. Lymphatic cells include macrophages, dendritic cells, and
lymphocytes. Lymphatic organs include the spleen and, the thymus. The lymphatic system is
responsible for maintaining body fluid balance and defending the body against infections. It consists
of a network of lymphatic vessels that transport lymph, a clear, watery fluid containing proteins,
salts, and other substances, across the body. There are three main functions of the lymphatic
system, these are firstly, maintenance of fluid balance, facilitation of the absorption of dietary fats
from the gastrointestinal tract to the bloodstream for metabolism or storage, and prevention of
infection. The lymphatic system is in charge of collecting extra interstitial water and protein, as well
as other cells, such as bacteria, which may enter the tissue through minor cuts or broken skin. The
lymphatic system transports bacteria and other antigens from the interstitial to lymphocytes in
lymph nodes, where an immune reaction can be triggered.
The spleen is an organ that generates lymphocytes, which
are essential components of the immune system, and is
situated in the upper-left portion of the body, not far from
the stomach. The spleen is the body's main lymphatic
organ/gland. The spleen is made up of two kinds of tissue:
white pulp and red pulp, which are separated by a
connective tissue capsule that stretches inward to split the
organ into lobules. The white pulp is lymphatic tissue that
is primarily made up of lymphocytes that surround
arteries. The spleen also filters blood, acts as the main
blood reservoir, and destroys old and aging blood cells (or abnormal, as in the case of sickle cells).
The spleen acts as a filter for blood. The spleen recognises and removes old or degraded red blood
cells from the body by breaking them down and saving any valuable components, such as iron, in the
process. This helps to keep the blood in the body sterile and operating correctly.
, Unit 8 – Lymphatic System
The thymus gland is located between the lungs in the chest. It produces T lymphocytes, which are
white blood cells that are part of the immune system that aid in the battle against infection. The
thymus gland is located in the middle of the chest between the lungs and below the breastbone in
the chest (sternum). It is located directly in front of and above the nucleus. T lymphocytes are white
blood cells produced by the thymus (also called T cells). They are vital components of the immune
system, which aid in the battle against infection. Before we reach the age of adolescence, the
thymus develops all of our T cells. It increasingly becomes less involved, shrinks, and is ultimately
replaced by fat tissue. Thymosin, a hormone produced by the thymus, aids in the formation and
development of T cells. The thymus gland is a lobular gland with an asymmetrical flat outline. The
lobules are made up of a collection of follicles that are both medullary and cortical: Each follicle's
cortical component is located on the periphery. Lymphocytes make up the majority of the tissue and
is supported by epithelial reticular cells. Each follicle's medullary component is located in the middle.
It has fewer lymphocytes and a higher number of epithelial cells than the cortex. Hassall's
corpuscles, which are concentric arrangements of epithelial reticular cells, are also present. Their
purpose is unknown.
The tonsils (palatine tonsils) are two soft tissue masses in the back of the throat (pharynx). Each
tonsil is made up of tissue that looks like lymph nodes and is coated with
pink mucosa (like on the adjacent mouth lining). Pits named crypts run
along the mucosa of each tonsil. The tonsils are an essential part of the
immune system. They can prevent germs from entering the body through
the mouth or nose because of their position at the throat and palate.
White blood cells, which are responsible for destroying germs, are also
abundant in the tonsils.
Lymph vessels (also known as lymphatic vessels) are thin-walled, valved structures that transport
lymph. Endothelial cells line lymph channels, which are connected to the surrounding tissue by a thin
layer of smooth muscles and adventitia. Lymph vessels have a similar
structure to blood vessels. Lymphatic vessels are a network of capillaries
(microvessels) and a vast network of tubes that carry lymph away from
tissues in the body. When lymph moves into wider vessels called
collecting ducts, lymphatic vessels absorb and filter it (at the nodes).
These vessels behave similarly to veins in that they run at low pressure
and have a system of valves that prevent the blood flowing in one
direction.
The lymph node is a small bean-shaped organ that is part of the immune system of the human body.
Lymph nodes include lymphocytes (white blood cells) that aid the body battle infection and illness by
filtering contaminants that pass across the lymphatic fluid. Hundreds of lymph nodes can be located
all over the body. They are linked together by lymphatic vessels. The spine, axilla (underarm),
stomach, belly, and groin all have lymph node clusters. In the axilla,
for example, there are between 20-40 lymph nodes. Also known as
the lymph gland. The capsule and the cortex are the two general
regions of each lymph node. The capsule is a connective tissue
membrane that covers the outside of the body. The lymph nodes,
also known as lymph glands, are thin, bean-shaped bodies made up
of lymphatic fluid. There are two main ways for cells to join a
lymph node.