Health Occupations
Lymphatic System
Functions of the Lymphatic
System

Works in conjunction with CV system
– Filters out organisms that cause disease
– Produces WBCs
– Makes antibodies
– Drains excess fluids & protein so tissues
do not swell up
Lymphatic fluid

Thin & watery
 Called interstitial fluid
– Forms when plasma diffuses into tissue spaces

Composed of
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Water
Digested nutrients
Salts
Hormones
Oxygen
CO2
Lymphocytes
Metabolic wastes
Vessels & Organs of the
Lymphatic System
Found in almost all tissues that have blood
vessels
1. Lymphatic capillaries
A. Tubes that reach into interstitial spaces
B. Small, open-ended like drain pipes
C. Lymph fluid contains waste products &
foreign bodies from cells
D. Fluid moves from capillaries to lymph
vessels
Vessels & Organs of the
Lymphatic System
Lymphatic capillaries also have
LACTEALS – specialized capillaries
found in small intestine
1. Pick up digested fats
2. Lymph + Lipids = Chyle
3. Transports chyle to
bloodstream via thoracic duct
Vessels & Organs of the
Lymphatic System
2.
Lymphatic vessels
A. Similar to veins
B. Muscular contractions help to move lymph from
tissues to lymphatic trunks
C. Valves prevent backflow of lymph so it moves in
only one direction, towards heart
D. Fluid empties in lymphatic trunks which empty
into veins & then become part of the blood
plasma
Vessels & Organs of the
Lymphatic System
3.
Lymph nodes
A.
B.
C.
D.
E.
Lie along lymph vessels
Small, round or oval masses
Size of pinhead to almond
Usually found in groups or clusters
Job is to filter lymph & remove impurities like
carbon, CA, pathogens, dead blood cells
F. Also produce lymphocytes & antibodies
G. Purified lymph with lymphocytes & antibodies
added leave node via ONE lymphatic vessel
H. Found in neck, armpit, chest, abdomen, elbows,
groin, knees
Vessels & Organs of the
Lymphatic System
4.
Lymphatic ducts – all lymph vessels drain
into these
A. Right lymphatic duct
A. Short tube receiving all purified lymph from right side of
head, neck, right chest, & right arm
B. Drains into right subclavion vein
B. Thoracic duct
A. Drains purified lymph from rest of body
B. Empties into left subclavion vein
C. Cisterna chili – enlarged pouch like structure @ start of
thoracic duct
1. Serves as storage area for purified lymph before it
returns to blood stream
2. Picks up chyle (digested lipids) from lacteals
Vessels & Organs of the
Lymphatic System
5.
Tonsils
A. Masses of lymph tissue that are external
B. Filter interstitial fluid, not lymph
C. If too much bacteria is filtered, pathogen can
overwhelm tonsils & they can become infected
D. 3 pairs of tonsils
1. Palatine tonsils – on each side of soft palate
2. Pharyngeal tonsils – adenoids, in nasopharnyx
3. Lingual tonsils – on back of tongue
Vessels & Organs of the
Lymphatic System
6.
Spleen
A. Organ located beneath left side of
diaphragm & behind upper stomach
B. Filters microorganisms & wastes
C. Makes lymphocytes & monocytes
D. Destroys old erythrocytes & stores
RBCs to release into bloodstream if there is
excessive bleeding
E. Destroys platelets
Vessels & Organs of the
Lymphatic System
7.
Thymus
A. Mass of lymphatic tissue located in front of aorta
& behind sternum
B. Stores lymphocytes to defend body only in
CHILDREN
C. Atrophies after puberty & is replaced by fat &
connective tissue
D. During childhood, makes lymphocytes &
antibodies
E. Function is taken over by lymph nodes in adults
Immunity
Lymph system helps body remove foreign
& harmful substances
1. Antigen – foreign matter that causes
body to produce antibodies (poison,
splinter, bacteria)
2. Antibody – substance made by body
to produce immunity to antigen
2 forms of immune response
1.
Nonspecific – innate, provides general
protection
A. Barrier of skin, mucous membranes, tears,
leukocytes
1. Forms antibodies in response to antigens or foreign
material
B. Inflammatory response - localized
1. Injured cells cause release of chemicals, causing
vascular dilation & increased blood flow
2. Other molecules enter area, wall off injured tissue
3. Bacteria are destroyed by WBCs
4. Area is red, warm, painful, & often swollen with
decreased function
2 forms of immune response
C. Inflammatory response – systemic
1. Affects entire body
2. Same as localized, but with increased
neutrophils, fever, & fluid loss in tissues
3. If not stopped, can lead to shock & death
2.
Specific immunity
A. Inherited – develops before birth, is
genetic (example – humans don’t
contract simian AIDS)
2 forms of immune response
B. Acquired
1. May be natural or artificial, depends on
how it was attained
a. Natural acquired
unintentional exposure like
immunity from breast milk
b. Artificial acquired
obtained intentionally like
immunization
Immune response may damage
tissue
1.
2.
3.
4.
With allergen exposure, plasma & memory
cells produced. The next exposure causes
anaphylactic response
Cytoxic response when antibodies react
with cells causing cellular destruction (RH
incompatability)
Phagocytes released to remove antigenantibody complexes & their actions cause
by-products that can cause tissue damage
Delayed hypersensitivity – occurs more
than 12 hours after exposure & results in
tissue damage
Abnormal conditions
1.
Lymphadenitis – inflammation or infection of
lymph nodes
A. Occurs when large amounts of harmful
substances enter lymph nodes
B. Symptoms – fever, swollen, painful
nodes
C. If untreated, nodal abscess may form
D. Treatment – warm moist compresses,
antibiotics, occasionally drain abscess
2. Hodgkin’s lymphoma

Chronic, malignant disease of lymph nodes
 Most common form of lymphoma
 Symptoms
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
Painful swelling of nodes
Fever
Night sweats
Weight loss
Fatigue
Pruritis (itching)
Treatment
– Chemo & radiation
3. Lymphangitis

Inflammation of lymph nodes, usually from
infected extremity
 Symptoms
– Red streak extending up an arm or leg from
source of infection
– Fever
– Chills
– Pain or tenderness

Treatment
– Antibiotics
– Rest & elevation
– Warm, moist compresses
4. Lymphedema
Caused by lymphatic obstruction
 Commonly occurs after lymph node
removal
 Especially after mastectomy

5. Splenomegaly

Enlargement of spleen
 Causes
– Abnormal accumulation of RBCs
– Mononucleosis
– Cirrhosis of liver

Symptoms
– Swelling & abdominal pain

Can lead to anemia, leucopenia,
thrombocytopenia
 If spleen ruptures, hemorrhage & shock, if
untreated, death
 May need to remove spleen
6. Tonsillitis

Inflammation or infection of tonsils
 Usually pharyngeal or palatine tonsils
 Symptoms
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Throat pain
Dysphagia (difficult swallowing)
Fever
Exudate on tonsils
Swollen mandibular lymph glands
Treatment
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Antibiotics
Warm saline irrigations
Analgesics
May remove with chronic infection or enlargement