1. Introduction
- The lymphatic
system is a part of the circulatory and immune systems.
- It helps
in:
- Returning
excess tissue fluid to the blood
- Absorption
of fats from the intestines
- Protecting
the body from infections
- It
consists of lymph, lymph vessels, lymphatic organs, and tissues.
2. Components of the
Lymphatic System
- Lymph – the
fluid transported
- Lymphatic
vessels – carry the lymph
- Lymph
nodes – filter the lymph
- Lymphatic
organs – like thymus and spleen
- Lymphatic
tissues – like tonsils, Peyer’s patches
3. Primary and
Secondary Lymphatic Organs
A. Primary Lymphatic Organs
- These are
where lymphocytes are produced and mature.
- Bone
marrow: Produces all blood cells including lymphocytes
- Thymus:
T-lymphocytes mature here
B. Secondary Lymphatic Organs
- These are
where lymphocytes get activated and respond to pathogens.
- Lymph
nodes
- Spleen
- Tonsils
- Mucosa-associated
lymphoid tissue (MALT)
4. Lymphatic Vessels
- Thin-walled
tubes that carry lymph
- Found
throughout the body, except:
- Brain,
bone marrow, eyeball
- Types:
- Afferent
vessels – bring lymph to lymph nodes
- Efferent
vessels – carry lymph away from nodes
- Have valves
to ensure one-way flow
5. Lymph
- Clear,
colorless fluid similar to plasma
- Formed by
filtration of plasma into tissues
- Contains:
- Water,
proteins, fats
- Lymphocytes
(mostly T & B cells)
- Sometimes
bacteria/foreign particles
6. Lymphatic
Capillaries
- Smallest
lymph vessels
- Blind-ended tubes in
tissues
- Found near
blood capillaries
- Highly
permeable – absorb fluid, proteins, lipids, and pathogens
- Unite to
form larger lymphatic vessels
7. Lymphatic Tissues
- Collections
of lymphocytes and reticular tissue
- Found in:
- Lymph
nodes
- Spleen
- Tonsils
- Peyer’s
patches
- Functions:
- Filter
lymph
- Trap
pathogens
- Help
immune response
Tags
ANATOMY