1. The Lymphatic System

2. What is the Lymphatic System
System working closely with circulatory system
Excess or unwanted tissue fluid is returned to the bloodstream

3. Functions Lymphatic System
Drains excess fluid
Transports fats and fat soluble vitamins from the digestive tract through the “Lacteals” into the blood
Plays a vital role in immune system
Digestive - lymphatic vessels in small intestines help with the absorption of fats during digestion - they are then transported around the body in the circulatory system and distributed by cells to be used as energy
Muscular - lactic acid formed from exercising muscles or from tension in muscles are drained away in lymphatic system

4. Structure of Lymphatic System
Lymphatic capillaries
Lymphatic vessels
Lymphatic nodes
Lymphatic ducts
Spleen
Tonsils
Thymus
Bone marrow

5. What is Lymph Fluid similar to blood plasma
Excess or unwanted tissue fluid
Lympha = clear water

6. Formation and Flow of Lymph
Plasma freely moves through the capillary wall to form interstitial fluid
More fluid travels from the blood capillary wall than returns because the pressure inside the capillaries is too high
The excess fluid (approx. 3 litres) per day drains into lymphatic capillaries and becomes lymph
Most plasma proteins are too large to leave blood vessels
So interstitial fluid contains only a small amount of protein
Any protein that does escape cannot return to blood by diffusion - high levels inside low levels outside prevent this
Important function of lymphatic vessels is to return leaked plasma proteins to the blood

7. Lymph circulation Valves ensure one way movement
Muscles - a milking action caused by muscle contraction
Respiratory pump - pressure changes during inhalation causes lymph to flow from abdominal region to thoracic region
Suction - negative pressure helps pull lymph upwards into lymphatic ducts

8. Sequence of Flow of Lymph
Arteries (blood)
Blood Capillaries (blood)
Tissue and Cells (interstitial fluid)
Lymphatic Capillaries (lymph)
Lymphatic Ducts (lymph)
Subclavian Veins (blood)

9. What are Lymphatic Capillaries
Lymph capillaries are found throughout the body
Slightly larger than blood capillaries
Single layer of Endothelial Cells which overlap - when pressure is greater in interstitial fluid - the cells separate slightly and fluid enters the capillary
Avascular - without blood vessels - the vessels located in the adjacent connective tissue that supply nutrients and remove waste
Endothelium - layer of simple squamous epithelium - lines cavities of heart blood vessels and lymphatic vessels

10. Lymphatic Capillaries

11. Lymphatic Vessels
Lymphatic Capillaries unite to form larger Lymphatic Vessels
Resembling veins in structure
thinner walls and more valves
Function
Collect lymph from lymphatic capillaries and convey towards the heart
In the intestine the lymphatic vessels are called Lacteals
Digestive - lymphatic vessels in small intestines help with the absorption of fats during digestion - they are then transported around the body in the circulatory system and distributed by cells to be used as energy
In the skin lymphatic vessels lie in subcutaneous tissue (between dermis of skin and deep fascia of the muscles) and generally follow veins

12. Lymph Nodes
Location - scattered throughout the body in groups and typically arranged in two sets
superficial and deep
Size varies from pin head to an almond
Structure - made of lymphatic tissue - surrounded by tough fibrous tissue and supported by strands of fibrous tissue called Trabeculae
Afferent vessel transports lymph to node
Efferent vessel transports from the node

13. Lymph Nodes of the Head Anterior Auricular Nodes
Posterior Auricular Nodes
Submandibular
Nodes
Occipital
Nodes
Cervical
Nodes

14. Key Lymph Nodes Submandibular Nodes
Superficial and Deep Cervical Nodes
Anterior / Posterior Auricular Nodes
Occipital Nodes
Axillary Nodes
Supratrochlear Nodes
Inguinal Nodes
Popliteal Nodes

15. Functions of Lymph Nodes
Filters harmful cells and dead tissue
Destroys harmful material
Produce new lymphocytes (white blood cells)
Produces antibodies against particular infections

16. Lymphatic Tissue Key part of immune system Contains many cells
Phagocytes - engulf and destroy harmful waste and bacteria
Cells producing antibodies and cells dividing to produce new lymphocytes
Areas of body containing lymph tissue include:
Lymph nodes, spleen, tonsils,
Bone marrow, thymus gland
Peyers patches, appendix
Payers patches - located in small intestine - prevent bacteria from entering the blood stream
Thymus Gland - between the lungs - Immature T Cells mature in the Thymus Gland - using Thymic Hormones - is large in an infant and after puberty fat and connective tissue replace much of the thymic tissue - after maturity the gland has atrophied
2 main types of lymphocytes -
B Cell Lymphocytes - responsible for producing Antibodies
T Cell Lymphocytes - various roles in immune system including destroying foreign substances

17. Lymphatic Ducts Lymphatic vessels join to form Lymphatic Ducts
All lymph passes into two main
lymphatic ducts:
The Right Lymphatic Duct
The Thoracic Duct
Right Lymphatic Duct
right side of head, chest and neck and right arm, into right Subclavian Vein
Thoracic Duct
the left side of the head, the neck, both legs, left side of trunk and left arm, into the Subclavian Vein
Thoracic Duct- 40cm long extending from second vertebra to the root of neck
Right Lymphatic Duct - 1.5cm long positioned at root of the neck

18. Routes for drainage of lymph into Thoracic Duct and Right Lymphatic Duct

19. The Spleen
Structure - largest mass of lymphatic tissue, outer capsule of fibrous tissue with trabeculae & pulp mass.
Location - located upper left of the abdomen
Functions;
Forms new lymphocytes
Destroys worn out thrombocytes and erythrocytes
Blood reservoir in case of haemorrhage and shock
Helps fight infection
Spleen - is about 12cm in length
Does not filter lymph - no afferent or efferent vessels
Ruptured Spleen - organ most often damaged in cases of abdominal trauma - Removal of Spleen called a Splenectomy - prevents patient bleeding to death - function taken over by Liver and Bone Marrow

20. Non-Hodgkin’s Lymphoma
Hodgkin’s Disease
Non-Hodgkin’s Lymphoma
Cancer of the lymphatic Tissue (Epstein Barr virus)
Usually arising in lymph nodes (15 to 35)
Painless enlargement of one or more lymph nodes
Fatigue
Weight loss
Treatment
Radiotherapy
Chemotherapy
Bone marrow transplant
Hodgkin’s Disease is curable
Cancer of the lymphoid tissue, which includes the lymph nodes, spleen, and other organs of the immune system (over 60’s)

21. Hashimoto’s Thyroiditis
Lymphoma
Lymphoma - a cancer that begins in the lymphocytes of the immune system
An autoimmune disease where the body's own T-cells attack the cells of the thyroid

22. Oedema Water retention
Lymphoedema
Accumulation of lymph fluid
Abnormal swelling
Cause
Lymphatic vessels damaged
Lymph node removal
Lymphatic fluid builds up as lymph system cant cope
Protein rich fluids build up and swelling begins
Excess Fluid in the interstitial compartment resulting in tissue swelling
Causes
Lymphatic blockages, impairment in body diluting urine
Renal failure
Liver failure

23. Infectious Mononucleosis
Lymphadenitis
Glandular Fever
Young adults & teenagers.
Virus is contagious
Passed on by close contact.
Antibodies created which provide lifelong immunity
Rare to have more than one bout of glandular fever.
Inflammation of a lymph node
Complication bacterial infection of a wound
Can be caused by virus

24. Cellulite Dimpled appearance of skin
Caused by fat deposits just below the surface skin.
It generally appears on skin in the abdomen, lower limbs, and pelvic region