sub 1.4 - lymphatic system (part 1)

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PREPARED BY :

EN. MUHD FAZLI DOLLAH

BIOLOGY FORM 5



LYMPHATIC SYSTEM



LEARNING OUTCOMES

1. Describe the formation of interstitial fluid

2. State the composition of interstitial

fluid3. State the importance of interstitial

fluid

4. Describe the fate of interstitial fluid5. Describe the structure of the

lymphatic system



THE LYMPHATIC SYSTEM

Part of the circulatory system & immune system.

A closed system consist of a network of lymphatic

vessels, ducts & nodes.

No pump, the fluid (lymph ) id squeeze along thelymphatic vessels by pressure associated withmovements of skeletal muscles, intestinal movements

& breathing.

Thymus & spleen are important organs of lymphaticsystem.



F ORMATION OF

INTERSTITIAL F LUID

Blood flows from arteries

capillaries, there is a higher

hydrostatic pressure at the arterial

end of the capillaries



LYMPHATIC FLUID

Oxygenated blood @ arterial end of the

capillaries high pressure force water &

dissolved substances out capillary wall

interstitial spaces (spaces between cells)

interstitial fluid/ tissue fluid/ extracellular fluid.

Erythrocytes & plasma protein are too large to

pass through remain in the capillary.



COMPOSITION OF INTERSTITIAL FLUID

Contains water + dissolved oxygen + amino acids +glucose + fatty acids + glycerol + vitamins + minerals +hormones.

An adult has ~11 litres of interstitial fluid providing thecells of the body with nutrients & a means of wasteremoval.

At the venous end of the capillary 90% absorbs by

blood consists of water, minerals & waste products.

The rest passes back into the BCS as lymph via theLYMPHATIC SYSTEM.



The Importance of Interstitial Fluid

Carries dissolved substances (O2,

amino acids, glucose, fatty acids,

glycerol, vitamins, minerals &hormones) to cells for exchange.

Carries waste products (CO2, urea,

etc.) into BCS.



THE FATE OF INTERSTITIAL FLUID

10% of interstitial fluid drains into thelymphatic capillaries forming lymph.

Move due to the contraction & relaxation of

skeletal muscles backflow is prevented by

semilunar valves.

Lymph in the right lymphatic duct & thethoracic duct flows into the right & left

subclavian veins of the BCS, respectively.



THE STRUCTURE OF THE LYMPHATIC

SYSTEM

Starts from the minute blind-ended tubesincluding lacteals (in the ileum) & lymphaticcapillaries in other tissues.

Lymphatic capillaries form largerlymphatic vessels lymphatics.

Semilunar valves are present along thelymphatics.

Lymphatics from all parts of the body twolarge ducts the right lymphatic duct, thethoracic duct.



THE STRUCTURE OF THE

LYMPHATIC SYSTEM

Situated at intervals along the lymphaticsare the oval-shaped structures lymphnodes (neck, armpits & groin).

Lymphocytes are found in the lymph nodes produce antibodies & play an importantrole in the body·s immune system.

Phagocytes in the lymph nodes help toremove bacteria.

sub 1.4 - lymphatic system (part 1)

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