HUMAN ANATOMY
& PHYSIOLOGY.
PREPARED BY:
MUHAMMAD UMAR
SU01-BBETM-F22-014
DEPARTMENT:
BIOMEDICAL ENGINEERING
SECOND SEMESTER
PREPARED FOR:
MAM SANA NADEEM
TOPIC:
THE LYMPHATIC SYSTEM
REFERENCES:
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BIOMEDICAL ENGINEERING
Medical terminology a living language 7th edition
my.clevelandclinic.org
www.cancer.gov
Medical news today.com
LYMPHATIC SYSTEM
The Lymphatic System
Function:
The lymphatic system consists of a network of lymph vessels that pick up excess tissue fluid,
cleanse it, and return it to the circulatory system. It also picks up fats that have been absorbed by
the digestive system. The immune system fights disease and infections. The lymphatic system is
our body’s ‘sewerage system’. It maintains fluid levels in our body tissues by removing all fluids
that leak out of our blood vessels. The lymphatic system is important for the optimal functioning
of our general and specific immune responses.
Organs:
The primary structures that comprise the lymphatic and immune systems:
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Lymph nodes.
Lymphatic vessels.
Spleen.
Thymus gland.
Tonsils.
Anatomy & Physiology of Lymphatic System:
BIOMEDICAL ENGINEERING
LYMPHATIC SYSTEM
The lymphatic system consists of a network of lymphatic vessels, lymph nodes, the spleen, the
thymus gland, and the tonsils. These organs perform several quite diverse functions for the body.
First, they collect excess tissue fluid throughout the body and return it to the circulatory system.
The fluid, once inside a lymphatic vessel, is referred to as lymph. Lymph vessels located around
the small intestines, called lacteals, are able to pick up absorbed fats for transport. Additionally,
the lymphatic system works with the immune system to form the groups of cells, tissues, organs,
and molecules that serve as the body’s primary defense against the invasion of pathogens. These
systems work together, defending the body against foreign invaders and substances, as well as
removing the body’s own cells that have become diseased.
1-Lymphatic Vessels:
The lymphatic vessels form an extensive network of ducts throughout the entire body. However,
unlike the circulatory system, these vessels are not in a closed loop. Instead, they serve as one-way
pipes conducting lymph from the tissues toward the thoracic cavity. These vessels begin as very
small lymphatic capillaries in the tissues. Excessive tissue fluid enters these capillaries to begin
the trip back to the circulatory system. The capillaries merge into larger lymphatic vessels. This is
a very low-pressure system, so these vessels have valves along their length to ensure that lymph
can only move forward toward the thoracic cavity. These vessels finally drain into one of two large
lymphatic ducts, the right lymphatic duct or the thoracic duct. The smaller right lymphatic duct
drains the right arm and the right side of the head, neck, and chest. This duct empties lymph into
the right subclavian vein. The larger thoracic duct drains lymph from the rest of the body and
empties into the left subclavian vein.
Visual representation of Lymphatic Vessels
BIOMEDICAL ENGINEERING
LYMPHATIC SYSTEM
2-Lymph Nodes:
Lymph nodes are small organs composed of lymphatic tissue located along the route of the
lymphatic vessels. These nodes, also referred to as lymph glands, house lymphocytes and
antibodies and therefore work to remove pathogens and cell debris as lymph passes through them
on its way back to the thoracic cavity. Lymph nodes also serve to trap and destroy cells from
cancerous tumors. Although found throughout the body, lymph nodes are particularly concentrated
in several regions. For example, lymph nodes concentrated in the neck region drain lymph from
the head.
Anatomy of Lymph Node
3-Tonsils:
The tonsils are collections of lymphatic tissue located on each side of the throat or pharynx. There
are three sets of tonsils: palatine tonsils, pharyngeal tonsils (commonly referred to as the
adenoids), and lingual tonsils. All tonsils contain a large number of leukocytes and act as filters
to protect the body from the invasion of pathogens through the digestive or respiratory systems.
Tonsils are not vital organs and can safely be removed if they become a continuous site of
infection.
BIOMEDICAL ENGINEERING
LYMPHATIC SYSTEM
4-Spleen:
The spleen, located in the upper left quadrant of the abdomen, consists of lymphatic tissue that is
highly infiltrated with blood vessels. These vessels spread out into slow-moving blood sinuses.
The spleen filters out and destroys old red blood cells, recycles the iron, and also stores some of
the blood supply for the body. Phagocytic macrophages line the blood sinuses in the spleen to
engulf and remove pathogens. Because the blood is moving through the organ slowly, the
macrophages have time to carefully identify pathogens and worn-out red blood cells. The spleen
is also not a vital organ and can be removed due to injury or disease. However, without the spleen,
a person’s susceptibility to a bloodstream infection may be increased.
Anatomy of Spleen
5-Thymus Gland:
The thymus gland, located in the upper portion of the mediastinum, is essential for the proper
development of the immune system. It assists the body with the immune function and the
development of antibodies. This organ’s hormone thymosin, changes lymphocytes to T
lymphocytes (simply called T cells), which play an important role in the immune response. The
thymus is active in the unborn child and throughout childhood until adolescence, when it begins
to shrink in size.
Anatomy of Thymus Gland
BIOMEDICAL ENGINEERING
LYMPHATIC SYSTEM
Obligations of Lymphatic system:
Your lymphatic system has many functions. Its key functions include:
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Maintains fluid levels in your body: As just described, the lymphatic system collects
excess fluid that drains from cells and tissue throughout your body and returns it to your
bloodstream, which is then recirculated through your body.
Absorbs fats from the digestive tract: Lymph includes fluids from your intestines that
contain fats and proteins and transports it back to your bloodstream.
Protects your body against foreign invaders: The lymphatic system is part of the
immune system. It produces and releases lymphocytes (white blood cells) and other
immune cells that monitor and then destroy the foreign invaders — such as bacteria,
viruses, parasites and fungi — that may enter your body.
Transports and removes waste products and abnormal cells from the lymph.
Conditions that affect Lymphatic System:
Many conditions can affect the vessels, glands, and organs that make up the lymphatic system.
Some happen during development before birth or during childhood. Others develop as a result of
disease or injury. Some diseases and disorders of the lymphatic system include:
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Enlarged (swollen) lymph nodes (lymphadenopathy):
Enlarged lymph nodes are caused by infection, inflammation or cancer. Common
infections that can cause enlarged lymph nodes include strep throat, mononucleosis, HIV
infection and infected skin wounds. Lymphadenitis refers to lymphadenopathy that is
caused by an infection or inflammatory condition.
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Swelling or accumulation of fluid (lymphedema):
Lymphedema can result from a blockage in the lymphatic system caused by scar tissue
from damaged lymph vessels or nodes. Lymphedema is also often seen when lymph
nodes are removed from those who've had surgery or radiation to remove cancer. The
buildup of lymphatic fluid is most commonly seen in your arms and legs. Lymphedema
can be very mild or be quite painful, disfiguring and disabling. People with lymphedema
are at risk for serious and potentially life-threatening deep skin infections.
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Cancers of the lymphatic system:
Lymphoma is cancer of the lymph nodes and occurs when lymphocytes grow and
multiply uncontrollably. There are several different types of lymphoma,
including Hodgkin’s lymphoma and non-Hodgkin’s lymphoma. Cancerous tumors can
also block lymphatic ducts or be near lymph nodes and interfere with the flow of lymph
through the node.
BIOMEDICAL ENGINEERING
LYMPHATIC SYSTEM