Lymphatic SystemLymphatic System

A&P Chapter 15A&P Chapter 15

Pg 461Pg 461

IntroductionIntroduction

Consists of : lymph, lymph Consists of : lymph, lymph vessels, lymph nodes, and lymph vessels, lymph nodes, and lymph tissuetissue

LymphLymph

Thin watery fluidThin watery fluidMade of interstitial, or Made of interstitial, or intercellular fluid that forms when intercellular fluid that forms when plasma diffuses into tissue plasma diffuses into tissue spaces.spaces.Composed of water, digested Composed of water, digested nutrients, salts, hormones, CO2, nutrients, salts, hormones, CO2, lymphocytes, and metabolic lymphocytes, and metabolic wastewaste

Lymphatic VesselsLymphatic Vessels

Located throughout the bodyLocated throughout the bodyLymphatic capillaries: small Lymphatic capillaries: small saclike open-ended vessels; acts saclike open-ended vessels; acts like drainpipes; picks up lymph at like drainpipes; picks up lymph at tissues throughout the body; tissues throughout the body; capillaries joint together to form capillaries joint together to form larger lymphatic vesselslarger lymphatic vesselsLymphatic vessels carry lymphLymphatic vessels carry lymphSkeletal muscle contraction causes Skeletal muscle contraction causes lymph flowlymph flow

Lymphatic Vessels cont’Lymphatic Vessels cont’Vessels pass through lymph Vessels pass through lymph nodesnodes

Contain valves that keep Contain valves that keep lymph flowing in one directionlymph flowing in one direction

Specialized lymphatic Specialized lymphatic capillaries (lacteals) are capillaries (lacteals) are located in the small intestinelocated in the small intestine– Pick up digested fats or lipidsPick up digested fats or lipids– Lymph is mixed with lipids = Lymph is mixed with lipids =

chylechyle– Lacteals transport chyle to the Lacteals transport chyle to the

bloodstreambloodstream

Lymph NodesLymph Nodes

Popularly called “glands”Popularly called “glands”

Located all over the body, Located all over the body, usually in small clustersusually in small clusters

Small round masses ranging in Small round masses ranging in size from a pinhead to an almondsize from a pinhead to an almond

Lymph vessels bring lymph to Lymph vessels bring lymph to the nodesthe nodes

Lymph NodesLymph NodesNodes filter out impurities such as:Nodes filter out impurities such as:– CarbonCarbon– Cancer cellsCancer cells– PathogensPathogens– Dead blood cellsDead blood cellsLymphatic tissue in nodes also Lymphatic tissue in nodes also produce lymphocytes: (a type of produce lymphocytes: (a type of leukocyte= WBC), and antibodies leukocyte= WBC), and antibodies (substances that fight infection)(substances that fight infection)

Lymph NodesLymph Nodes

Purified lymph, with Purified lymph, with lymphocytes and antibodies lymphocytes and antibodies added leaves the lymph node added leaves the lymph node by a single lymphatic vesselby a single lymphatic vessel

Lymphatic DuctsLymphatic Ducts

As lymphatic vessels leave As lymphatic vessels leave the lymph nodes, they the lymph nodes, they continue to join together to continue to join together to form larger lymph vesselsform larger lymph vessels

Eventually they drain into Eventually they drain into one of two lymphatic ducts: one of two lymphatic ducts: Right or the Thoracic Right or the Thoracic

Lymphatic DuctsLymphatic DuctsRight Duct:Right Duct:– Short tubeShort tube– Receives all the purified Receives all the purified lymph form the right side lymph form the right side of the neck and head, the of the neck and head, the right chest, and the right right chest, and the right armarm

Lymphatic DuctsLymphatic Ducts

Thoracic DuctThoracic Duct::

Much larger tubeMuch larger tube

Drains lymph from the rest Drains lymph from the rest of the bodyof the body

Empties into the R Empties into the R Subclavian Vein, returning Subclavian Vein, returning purified lymph to the bloodpurified lymph to the blood

Lymphatic DuctsLymphatic Ducts

Thoracic DuctThoracic Duct cont’ cont’

Enlarged pouchlike structure Enlarged pouchlike structure called the cisterna chyli is called the cisterna chyli is located at the start of the located at the start of the thoracic duct and serves as thoracic duct and serves as storage area for purified lymphstorage area for purified lymph

Lymph TissueLymph TissueLocated throughout the body in Located throughout the body in addition to being in lymph nodesaddition to being in lymph nodesTonsils, spleen, and thymus are Tonsils, spleen, and thymus are examples of lymphatic tissueexamples of lymphatic tissueTonsils:Tonsils: Masses of lymph tissue; Masses of lymph tissue; filterfilter interstitial fluid; 3 pairs of interstitial fluid; 3 pairs of tonsils=tonsils= palantine, pharngeal palantine, pharngeal (adenoids), and lingual(adenoids), and lingual

Lymph TissueLymph TissueSpleenSpleenOrgan located on L side in back Organ located on L side in back of the upper part of the stomachof the upper part of the stomachProduces leukocytes and Produces leukocytes and antibodiesantibodiesDestroys old RBC’s; Stores RBC’sDestroys old RBC’s; Stores RBC’sDestroys thrombocytes, Destroys thrombocytes, Filters some metabolites and Filters some metabolites and wastes from tissuewastes from tissue

Lymph TissueLymph TissueThymusThymus

Mass of lymph tissue Mass of lymph tissue located in the center of the located in the center of the upper chestupper chest

Atrophies or wastes away Atrophies or wastes away after puberty and is after puberty and is replaced by fat and replaced by fat and connective tissueconnective tissue

Lymph TissueLymph Tissue

Functions during early life by Functions during early life by producing antibodies and producing antibodies and manufacturing lymphocytes manufacturing lymphocytes to fight infectionto fight infection

Function is taken over by Function is taken over by lymph nodes after it lymph nodes after it atrophiesatrophies