The lymphatic system is part of the circulatory system and immune system. It is composed of a network of lymphatic vessels that carry lymph fluid towards the heart. Lymph contains plasma constituents too large to pass through blood capillaries, such as macroparticles from damaged areas. Lymphatic vessels originate as blind-ended tubes and contain valves to prevent backflow. They join to form larger vessels and ducts that drain into veins. Lymph nodes filter lymph and activate immune cells. Key lymphatic organs include the spleen, bone marrow, thymus gland and tonsils, which help generate and select lymphocytes.

1. ANATOMY AND PHYSIOLOGY OF
LYMPHATIC SYSTEM
BY:DIPALI HARKHANI

2. WHAT IS LYMPHATIC SYSTEM?
• The lymphatic system is part of
the circulatory system and an important
part of the immune system, comprising a
network of lymphatic vessels that carry a
clear fluid called lymph (from
Latin, lympha meaning
"water”)directionally towards the heart.

3. COMPOSITION OF LYMPH
• The composition of lymph is similar to
that of plasma but the constituents have
some additional substances that are too
large to pass through blood capillary
walls
• Ex.macroparticles from damaged area
• Dameged cells by disease and bacteria.

4. LYMPH VESSELS
• These originate as blind end tubes in the interstitial
spaces.
• Structurely,they are same as blood capillaries.
• Their walls are more permeable to all interstitial fluid
including proteins and cell debris.
• The capillaries joint to form larger lypmph vessels.
• Lymph vessels have numerous cup shaped valves that
prevent back flow of movements of lymph in vessels.
• Lymph vessels join together to form two larger ducts
• (i) The Thoracic duct
• (ii) The right Lymphatic duct

5. LYMPH VESSELS

6. (i) THE THORACIC DUCT
• What is duct?
A duct is a circumscribed channel leading from
an organ.
Length-40cm
Ascends through the diaphragm and passes
upwards in the thoracic cavity.
it drains Lymph from
Both legs
The pelvicabdominal cavities
Left half of the The Thorax
Head & Neck
The Left upper Limbs.

7. (ii) THE RIGHT LYMPHATIC DUCT
• IT LIES IN THE ROOT OF THE NECK AND OPEN
INTO RIGHT SUBCLAVIAN VEIN.
• IT DRAINS LYMPH FROM
RIGHT HALF OF THE THORAX
NECK
RIGHT UPPER LIMB

9. LYMPH NODES
• All the small and medium size lymph vessels open
into lymph nodes.
• The size of a node arise from pin head to the largest
is about the size of an almond
• Structure
• Has a fibrous capsule,dips down into the node
forming trabecula that divide the node into
compartments.
• Below the capsule is sub capsular substance.
• The outer portion is called cortex.
• The inner portion is called medulla.

12. LYMPH NODES
• It has tightly packed.
lymphocytes,macrophages and plasma cells.
• Functions
• Phagocytic action.
• Production of antibodies.
• Enlargement of lymph nodes,when the area of
drainage is infected.
• Activate T and B lymphocytes.
• Filtration of lymph.

13. LYMPHATIC TISSUE OR LYMPHATIC
ORGANS
• The lymphatic organs are found in a number of situations
n the body.
• such as
(i)Tonsils
(ii)Spleen
(iii)Bone Marrow
(iv)Thymus Gland
(i)Lonsils
Lingual Tonsils are the paired and lie at the base of the
tongue.

14. LINGUAL TONSILS

15. (ii)SPLEEN
• The Spleen is formed partly by lymphatic system.
• Location-left hypochondriac region
• Length-12 cm
• Width-7 cm
• Thick-2.5 cm
• Shape-oval
• Relations-
Posteriorly & Superiorly- Diaphragm
Inferiorly-Left colic flexure of large intestine
Anteriorly-Fundus of the stomach

16. STRUCTURE OF SPLEEN
• Enclosed in peritoneum.
• Covered by a capsule.
• The trabaculae subdivides the structure into lobules.
• The spleen don’t has no afferent lymphatic vessels.
• So it does not filter lymph.
• Spleen consists red and white pulp.
• Blood supply
• Splenic artery
• Splenic vein
• Lymphatic vessels
• Nerves

19. FUNCTIONS OF SPLEEN
• Phagocytosis of Bacteria
• Break down of RBC.
• Production of Antibodies.

20. (iii)BONE MARROW
• The Red Bone Marrow is a key element of
the lymphatic system,
• Being one of the primary lymphoid organs that
generate lymphocytes from immature
hematopoietic progenitor cells.
• The bone marrow and Thymus constitute the
primary lymphoid tissues involved in the
production and early selection of lymphocytes.
• Furthermore, bone marrow performs a valve-like
function to prevent the backflow of lymphatic
fluid in the lymphatic system.

22. (iv) THYMUS GLAND
• Weight-15 gms
Relations-
Anteriorly-Sternum.
Posteriorly –Aortic arch.
Superiorly- Root of neck.
Inferiorly-Heart.
Laterally-Lungs.
Lobes- two
Each lobule has aggregation of lymphocytes.
The cortex is composed of aggregation of lymphocytes.
Medulla contains less lymphocytes.
The Thymus gland develops mature T lymphocytes.

25. BLOOD SUPPLY TO THE THYMUS GLAND
• Inferior thyroid artery.
• Internal thoracic artery.
• Nerves derived from vagus nerve.
• Functions
• Activation of T-lymphocytes
• Production of antibodies.
• Production of Thymosin hormone.
[Thymosins are small proteins present in many
animal tissues. they are named thymosins because
they were originally isolated from the thymus]