PHYSIOLOGY OF HUMAN BODY
SYSTEMS
27/02/2023
UNIT 8B: LYMPHATIC SYSTEM
Understand the impact of disorders on the lymphatic system and the
associated corrective treatments.
,STRUCTURE AND FUNCTION OF ORGANS
Lymph Nodes: These are small, bean-shaped structures found throughout the
body in the neck, armpits, groin, and abdomen. Lymph nodes filter lymph fluid
and contain white blood cells which help fight infection.Lymph nodes are small,
round structures found throughout the body that serve an important role in the
immune system. They are located in the underarm, groin, neck, chest, abdomen
and other areas, and are connected to the lymphatic system. Lymph nodes work
by filtering out bacteria, viruses, and other foreign substances from the lymph
fluid as it passes through them.
The parts of the lymph nodes include:
Follicles: Follicles are round, bean-shaped structures that are the main working
parts of the lymph nodes. They contain white blood cells such as lymphocytes and
macrophages that fight infection.
Medulla: The medulla is a region at the center of the lymph node that contains
connective tissue and small blood vessels.
Capsule: The capsule is the outer layer of the lymph node that is made up of
collagen fibers and elastic fibers. It serves to protect the lymph node and keep it
structurally intact.
Sinuses: Sinuses are channels that connect the lymph node to the nearby
lymphatic vessels. They allow the lymphatic fluid to enter and exit the lymph
node.
Trabeculae: Trabeculae are small structures that form a network within the lymph
node. They provide support and allow for the movement of lymphatic fluid
through the lymph
Spleen: This organ is in the upper left side of the abdomen and filters old red
blood cells, produces new white blood cells, and store platelets.The spleen is
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, composed of two parts: the red pulp and the white pulp. The red pulp is the larger
of the two parts and is composed of tiny networks of vessels. These vessels filter
the blood, removing any damaged red blood cells, bacteria, and other debris. The
white pulp is a collection of lymphatic tissue that contains immune cells. White
blood cells are produced in the white pulp and are responsible for fighting
infections.
Thymus: This organ is located behind the sternum and is instrumental in the
development of T-cells, which are important in fighting infection.The thymus is
made up of two lobes, the left and right lobe, which are connected in the middle.
Each lobe is divided into three parts, the cortex, medulla, and capsule.
The cortex is the outer layer of the thymus and is made up of lymphocytes, which
are white blood cells. These cells are responsible for maturing and developing the
T cells, which are important in the immune response.
The medulla is the inner layer of the thymus and contains a collection of epithelial
tissue. This tissue is responsible for producing hormones, such as thymosins,
which help to regulate the maturation and development of T cells.
The capsule is the outer layer of the thymus and is made up of connective tissue.
This tissue helps to protect the thymus from any damage or injury.
Tonsils: These are clusters of lymphoid tissue located in the back of the throat and
help filter out bacteria and other foreign particles.The tonsils are composed of
various parts, including: Mucosa: This is the protective layer that lines the tonsils
and is composed of several layers of cells. This layer is responsible for secreting
mucus, which helps trap invading pathogens and prevent them from entering the
body.
Cortex: This is the middle layer of the tonsils and is composed of lymphoid tissue.
This layer houses B-cells, which help fight off bacteria and viruses.
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