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The lymphatic system consists of - The fluid : Lymph

- A network of : Lymphatic vessel (parallel to veins )

- Specially cells called: Lymphocytes - An array of : Lymphoid tissue and lymphoid

organs

This system closely associated with the CV system The lymphatic system differs from the circulatory

system in that the lymphatics do not form a closed ring or circuit.

Instead, begin blindly in the intercellular spaces of the soft tissues of the body.

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Lymphatic vessels drain excess fluid from the tissues and return it to the cardiovascular system.

The tonsils, spleen, thymus gland, and red bone marrow are among those lymphatic organs that assist immunity.

Lymphatic vessels, like cardiovascular veins, have valves to prevent backward flow.

3The lymphatic organsmaria immaculata iwo, sf, itb

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The lymphatic organs

Primary lymphatic organs - The red bone marrow and - thymus gland

Secondary lymphatic organs

- Lymph nodes - Spleen, - tonsils, - Payer patches - MALT - Appendix - Lacteals

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Lymphoid tissue and organs

Primary/central lymphoid Organ

Sumsum tulang Thymus

Lymphopoiesis place

Secondary/peripheral Lymphoid

1. Spleen mengumpulkan antigen dari darah

2. Lymph nodes mengumpulkan antigen dari jaringan

3. Lymphoid tissue berasosiasi dengan mukosa (MALT), tonsil: palatin, lingual dan faringeal; appendix, Payer patches Mengumpulkan antigen dari

permukaan epitel tubuh

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Three main functions of lymphatic system

1. Fluid balance.

The lymphatic system takes up excess tissue fluid and returns it to the bloodstream.

Recall that lymphatic capillaries lie very near blood capillaries, and they serve as an auxiliary way to take up fluid that has

exited the blood capillaries

2. Fat absorption.

The lymphatic system absorbs fats from the digestive tract and transports them to the bloodstream.

Special lymphatic capillaries called lacteals are located in the intestinal villi

This function ensures the absorption of dietary lipids as well as lipid-soluble vitamins.

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Three main functions of lymphatic system

3. Defense The lymphatic system helps defend the body against disease.

This function is carried out by the white blood cells present in lymphatic vessels and lymphatic organs.

To help distribute hormones, nutrients, and waste

maintaining continuous communication between blood and tissue

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Importance of the Lymphatic System • Two most important functions Maintenance of fluid balance in the internal environment.

prevent edema & restore interstitial fluid to cardiovascular syst. Immunity

• maintaining fluid balance.

– Plasma filters into the interstitial spaces from blood flowing through the capillaries.

– Much of this interstitial fluid is absorbed by tissue cells or reabsorbed by the blood before it flows out of the tissue.

• A small amount of interstitial fluid is left behind.

If this would continue over even a brief period of time, the increased interstitial fluid would cause massive edema tissue destruction or death

– This problem is avoided by the presence of lymphatic vessels that act as "drains" to collect the excess fluid and return it to the venous

blood just before it reaches the heart

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derived from the blood and tissue fluid, clear, watery fluid found in the lymphatic vessels.

Interstitial fluid fluid that fills the spaces around cells

another type of extracellular fluid

Composition:• interstitial fluid that enters lymph vessel becomes lymph fluid

• only a few of the plasma proteins leak out of blood capillaries & are then picked up by lymph vessels

• other solutes of plasma, interstitial fluid & lymph should be same

• lacks red blood cells & platelets

• WBCs are present in lymph, blood & interstitial fluid

Lymph

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General Composition of Extracellular Fluids

Fluid Blood Interstitial Fluid

Lymph

Red Blood Cells X

Platelets X

White Blood Cells X X X

Proteins - albumin, globulins...

X-lots Few Few

Other Solutes X x x

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Lymphatic Vessels Originate as microscopic blind-end vessels called lymphatic

capillaries

Formed by merging lymphatic capillaries;

Walls similar to veins and have valves to prevent backflow of lymph These lead to lymph nodes.

Lymphatic capillaries merge with other lymphatics to eventually form the main lymphatic trunks.

Lymphatic vessels resemble veins in structure with these exceptions:

- Lymphatics have thinner walls. - Lymphatics contain more valves. - Lymphatics contain lymph nodes located at

certain intervals along their course.

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• Routes for Drainage of Lymph From lymphatic capillaries, lymph flows

through progressively larger lymphatic vessels to eventually reenter blood at the junction of the internal jugular and subclavian veins

How lymph travels

- from extremities

Lymph capillaries lymphatic vessels nodes cysterna chyli (from both legs and abdomen)

thoracic duct (behind left brachiocephalic vein and left subclavian vein) then dumps into left subclavian vein

- from head

lymph vessel travel down and also dump into the left subclavian vein

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The Lymphatic Pump

– Lymph flows through the thoracic duct and reenters the general circulation at the rate of 125 mL/hour.

• Occurs despite the fact that most of the flow is against gravity or "uphill".

– It moves through the system in the right direction because of the large number of valves that permit fluid flow only in one direction.

– The movement is due to

breathing movements and

skeletal muscle contractions

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Lymphokinetic actions

• Activities that result in central movement or flow are called lymphokinetic actions. X-rays show that lymph pours into the central veins

most rapidly at the peak of inspiration.

The mechanism of inspiration,

This simultaneously causes pressure to increase in the abdominal portion of the thoracic duct and to decrease in the thoracic portion.

Research has shown that thoracic duct lymph is literally "pumped" into the venous system during inspiration.

The rate of flow of lymph into venous circulation is proportional to the depth of inspiration.

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The total volume of lymph that enters the central veins during a given time period depends on both the depth of inspiration and the overall breathing

rate.

Contracting skeletal muscles also exert pressure on the lymphatics to push the

lymph forward.

During exercise, lymph flow may increase as much as 10-15x.

In addition, segmental contraction of the walls of the lymphatics themselves, results in lymph being pumped from one

valve segment to the next.

• Other pressure generating factors: - Arterial pulsations - Postural changes - Passive compression (massage) of the body soft

tissues.

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LYMPH NODES

Lymph nodes located along the paths of collecting vessels. The main nodes are located in the: cervical, inguinal, and

in axyllary, pelvis, abdomen, and thorax region Lymph vessel:

- Afferent, brings lymph into the node- Efferent, brings lymph vessel leaving lymph node

Germinal centers centers of lymphoid tissue inside the node Cysterna Chyli a collecting duct that receives lymph from the lumbar and intestinal trunks They are typically located in groups along the larger lymphatic vessels, which follow the major blood vessels

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Functions like a kitchenClean the lymph Vein heart

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Functions of lymph node like a kitchen- Slows down flow of lymph as it passes through

- Filter ~ 99% of foreign material out of incoming lymph

- Trap & destroy foreign stuff caught in the reticular mesh

- Produce more lymphocytes during infection

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Problems of the systems

– Lymphangitis inflamasi pembuluh limfatik– Lymphadenopathy (Swollen glands/node)– Bubonic plaque hemorrhaging and swelling of the lymph

nodes– Radical Mastectomy surgery deep axillary lymph nodes– Cancer easily spread through lymphatic system

– Some Causes of Edema • obstruction of lymphatic vessel or vein (lymph edema) • filarial (round) worms inside vessels scar tissue blocks lymph • infection inflammation blood vessels get "leaky" • high blood pressure in capillaries excess fluid leaks out • form a pathway that can "trap" & then destroy foreign material • before it has a chance to enter high speed blood stream

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