Lymphatic SystemLymphatic System

Chapter 37Chapter 37

Section 2Section 2

CERVICAL NODES

THYMUS

LYMPHVESSELS

SPLEEN

INGUINALNODES

LYMPHVESSELS

LYMPHVESSELS

AXILLARYNODES

DIAPHRAGM

NotesNotes

Crucial in helping the body Crucial in helping the body ward off disease and heal from ward off disease and heal from

injuryinjury

Advanced infection frompoor circulation

FunctionFunction

1. Collects fluid lost from the blood and 1. Collects fluid lost from the blood and returns it to the circulatory systemreturns it to the circulatory system– More than three liters of fluid leave the More than three liters of fluid leave the

capillaries each daycapillaries each day– This continually bathes the cellsThis continually bathes the cells– There is twice as much lymph in the body There is twice as much lymph in the body

as bloodas blood– Lymph is dumped back into the circulatory Lymph is dumped back into the circulatory

system thru the superior vena cavasystem thru the superior vena cava

Functions cont’dFunctions cont’d

2. Filters fluid to rid it of bacteria and other 2. Filters fluid to rid it of bacteria and other pathogenspathogens

Lymph Capillaries in the Tissue SpacesTissue cells

Tissue spaces

Venule

Lymphatic vessel

Lymph capillary

Arteriole

Tissue fluid

More FunctionsMore Functions

3. Collects fat from the small intestine 3. Collects fat from the small intestine and delivers it to the circulatory and delivers it to the circulatory systemsystem

4. Generates and stores WBC’s called 4. Generates and stores WBC’s called lymphocytes that fight infection lymphocytes that fight infection

Noticethelocationof thenodes

Components of the Lymphatic Components of the Lymphatic SystemSystem

A. Lymph – fluid collected in lymph A. Lymph – fluid collected in lymph vesselsvessels

Clear straw colored fluid – same Clear straw colored fluid – same basic component as plasmabasic component as plasma

B. Lymph vessels – structures that B. Lymph vessels – structures that collect lymph and deliver it back to collect lymph and deliver it back to the circulatory systemthe circulatory system– Valves within keep the lymph moving in Valves within keep the lymph moving in

one directionone direction

Wall of lymphaticcapillary

Opening intolymph vessel

Tissue cell Tissue fluid

C. Lymph nodes = C. Lymph nodes = series of cleaning series of cleaning filtersfilters

Lymph moves Lymph moves slowly through the slowly through the nodesnodes

WBC’s attack and WBC’s attack and engulf bacteria and engulf bacteria and pathogens in nodespathogens in nodes

Location of vessels Location of vessels and nodesand nodes

The lymphatic system is The lymphatic system is closely linked to several other closely linked to several other

systemssystemsBut especiallyto theCirculatory System

Nodes swell when large Nodes swell when large numbers of pathogens are numbers of pathogens are

trappedtrappedThe swelling can cause pain – like a The swelling can cause pain – like a

sore throatsore throat

Have you ever had tonsillitis?Have you ever had tonsillitis?

Did itlook like this?

EdemaEdema

Swelling of tissues due to excess Swelling of tissues due to excess fluid accumulationfluid accumulation

Caused by disease or injuryCaused by disease or injury

ElephantiasisElephantiasis – a condition of extreme edema that a condition of extreme edema that

occurs when lymph vessels become occurs when lymph vessels become blocked by filarial worms. blocked by filarial worms.