Download lymph node

the lymphatic system
consists of
The lymph conducting
channels
Lymphoid tissues
Lymphoid organs
The lymphatic system is part of
the immune system and acts as a
secondary (accessory) circulatory
system.
Functions of the lymphatic system:
• remove excess fluids from body
tissues,
• absorb fatty acid and transport
fat to circulatory system, and
• produce immune cells
(lymphocytes, monocytes,
and plasma cells).
Blood fluid escapes through the
thin-walled capillaries into spaces
between body tissue cells.
Lymph vessels, which have very
thin walls, pick up these fluids
called lymph.
Composition
• Lymphatic vessel
– Lymphatic capillary
– Lymphatic vessels: two sets,
superficial and deep
– Lymphatic trunks: nine
– Lymphatic ducts: thoracic duct,
right lymphatic duct
• Lymphatic organ
– Lymphatic nodes
– Tonsil, spleen, thymus
• Lymphatic tissue
• Include diffused lymphoid tissues and
lymph nodules. They are mainly
situated in the wall of the respiratoryalimentary tracts and consist of
aggregated of lymphocytes and
associates cells.
Tissue fluid and its formation
- composition same as blood but without read
blood cells (RBCs), platelets & proteins
because they are too large to leak out of the
capillaries
- forms a link between blood and cells, providing
a medium for exchange of materials between
blood & cells
At the arterial end of a capillary, liquid is
forced out as tissue fluid which is similar
to plasma in composition except its has
no plasma proteins, platelets & RBCs.
At the venous end, some fluid returns to
blood while some enters lymph vessels
which eventually join to a vein near the
heart and thus returns to blood finally.
Lymph
some tissue fluid returns to capillaries by osmosis while
some (about 10%) goes into lymph capillaries;
this fluid is now called lymph
Path:
Blood  lymph capillaries
 lymph vessels
 lymph ducts
 Blood
- Lymph re-enters blood
Lymphatic capillary Begin
blindly
• The wall is composed of a
single layer of overlapping
endothelial cells
• They are numerous and form
complex networks
• The brain, spinal cord, bone
marrow, parenchyma of spleen
and eyeball lack lymphatic
capillaries
Lymph is driven by contraction of
surrounding muscles, aided by valves which
enable one-way flow to the neck.
Movement of lymph through the lymphatic system:
1. Hydrostatic pressure
2. Muscle contraction
3. Inspiratory movement
4.Valves to ensure one-way traffic towards the
heart
The Lymphatic System
Heart
Vein
Artery
Lymphatic duct
Lymphatic trunk
Capillaries
Lymphatic node
Cell
Tissue fluid
Lymphatic capillary
Lymphatic vessel
lymphatic vessels
• lymphatic capillary
• lymphatic vessel
• lymphatic trunks
• lumbar trunks(2)
• brochomediastinal
trunks(2)
• subclavian trunks(2)
• jugular trunks(2)
• intestinal trunk
• lymphatic ducts
• thoracic duct
• right lymphatic duct
Lymphatic vessel
Features of structure
 Three layered wall similar
to, but thinner than vein,
 More numerous valves
than in vein
 Interposed by lymph node
at interval along the course
 Arranged in superficial and
deep sets
Lymphatic trunks
 right and left jugular
trunks
 right and left subclavian
trunks
 right and left
bronchomediastinal trunks
 right and left lumbar
trunks
 intestinal trunk
Lymphatic ducts
Right lymphatic duct



Formed by union of right jugular,
subclavian, and bronchomediastinal
trunks
Ends by entering the right venous angle
Receives lymph from right half of head, neck,
thorax and right upper limb
 Thoracic duct
• Begins in front of L1 as a dilated
sac, the cisterna chyli , which
formed by joining of left and right
lumbar trunks and intestinal trunk
• Enter thoracic cavity by passing
through the aortic hiatus of the
diaphragm and ascends along on the
front of the vertebral column,
between thoracic aorta and azygos
vein
Thoracic duct
• Travels upward, veering to the left at
the level of T5
• At the roof of the neck, it turns
laterally and arches forwards and
descends to enter the left venous
angle
• Just before termination, it
receives the left jugular,
subclavian and bronchomediastinal
trunks
Thoracic duct
• Drains lymph from lower
limbs, pelvic cavity,
abdominal cavity, left side of
thorax, and left side of the
head, neck and left upper
limb
Lymphatic vessel
• Have valves that give them a beaded
appearance
• Two sets: superficial (lie in the
superficial fascia ) and deep (run
with blood vessels and nerves)
• Passes through at least one lymph
node and often several
lymphatic ducts
• thoracic duct
from cisterna chyli (L1)
to left venous angles
• left jugular trunk
• left subclavian trunk
• left bronchomediastinal trunk
• right and left lumbar trunk
• intestinal trunk
right lymphatic duct
• right brochomediastinal trunk
• right subclavian trunk
• right jugular trunk
The lymph vessels join to form
larger ducts that pass through
lymph nodes (or glands).
Each lymph node has a fibrous
outer covering (capsule), a
cortex, and a medulla.
lymph node
(Small oval or bean-shaped bodes
• Afferent vessels enter the node on
its convex surface, and efferent
vessels leave the node at its
concave surface－the hilum
• Arranged in groups, along the
blood vessels
• Regional nodes
• is the lymph node where the
lymph of the organ or part of the
body drainage to firstly
Photo from U. S. Federal Government courtesy of Wikipedia.
Lymph nodes filter foreign
substances, such as bacteria and
cancer cells, from the lymph before
it is re-entered into the blood
system through the larger veins.
Lymph nodes, which are scattered
among the lymph vessels, act as
the body’s first defense against
infection.
Lymph nodes produce the following
cells:
• Lymphocytes – a type of white
blood cell,
• Monocytes – a leukocyte that
protects against blood-borne
pathogens, and
• Plasma cells – produce antibodies.
Each lymph node has its own blood
supply and venous drainage.
The lymph nodes usually have names
that are related to their location in
the body.
When a specific location gets
infected, the lymph nodes in
that area will enlarge to fight
the infection.
If the lymph node closest to an
infected area is unable to
eliminate the infection, other
lymph nodes in the system will
attempt to fight the infection.
This is particularly critical in the
case of cancer, which can be
spread from its point of origin to
all parts of the body through the
lymphatic system.
Lymph drainage
of the body
The lymphatic drainage of
Lymph nodes of head head
• Located at junction of head and neck
• Consist of
– Occipital lymph nodes
– Mastoid lymph nodes
– Parotid lymph nodes
★ Submandibular lymph nodes
lies near the submandibular gland,
receive lymphatic vessels from the
face, nose and mouth
– submental lymph nodes
• Drain into deep cervical lymph nodes
Lymph nodes of the neck
Anterior cervical ln.
• Superficial anterior cervical lymph
nodes
• Deep anterior cervical lymph nodes
Lateral cervical ln. ★
Superficial lateral cervical ln. －
lie along the external jugular vein
★ Deep lateral cervical ln. －extend
along the internal jugular vein
Lymph nodes of the neck
★ Deep lateral cervical ln.
•
•
•
•
Extend along the internal jugular vein from the base
of skull to the root of neck
Divided into superior deep lateral cervical ln. and
inferior deep lateral cervical ln.
Receive lymphatic vessels from head, neck, tongue,
larynx, cervical parts of esophagus and trachea,
thyroid gland, upper parts of the thoracic wall and
breast
Efferent vessels form the jugular trunk
– Left jugular trunk joins the thoracic duct
– Right jugular trunk joins the right lymphatic duct
Lymph nodes of the neck
Superior deep lateral cervical ln.
Jugulodigastric ln.
– Lies at the junction of posterior belly of
digastric and internal jugular vein
– Drain the nasopharynx, palatine tonsil and
root of tongue
Inferior deep lateral cervical ln.
Juguloomohyoid ln.
– Lies at the junction of the intermediate
tendon of omohyoid and internal jugular
vein
– Drain the apex of tongue
Lymph nodes of the neck
Inferior deep lateral
cervical ln.
Supraclavicular lymph nodes
– Lie along transverse cervical a.
& v.
– palpable in the supraclavicular
fossa. The most notable
supraclavicular lymph node is
Virchow's node. which can
contain metastasis of visceral
(abdominal) tumor.
•
Retropharyngeal ln.
– Lying vertically behind the
pharynx
– drain nasopharyngeal lymph
Lymph nodes of upper limb
•
•
•
•
•
Cubital lymph node
lies above medial epicondyle of humerus
Receive lymph vessels from forearm
Axillary lymph node
arranged in five groups
Axillary lymph nodes
• Axillary lymph nodes vary
in size from a pin-head to a
large bean.
• They are arranged in five
groups.
Axillary lymph nodes
Pectoral lymph nodes
Lying along the lower
border of pectoralis minor
behind the pectoralis major
• Receive lymph vessels from
the lateral quadrants of the
breast and superficial
vessels from the
anterolateral abdominal wall
above the level of the
umbilicus
Axillary lymph nodes
Lateral lymph nodes
Along medial side distal part
of axillary vein
• Receives lymph from upper
limb
Axillary lymph nodes
Subscapular lymph
node
• Lying along subscapular
vessels, in front of the
subscapularis
• Receive superficial lymph
vessels from the back,
down as far as the level of
the iliac crests
• Efferents of above three
groups pass to central
lymph node
Axillary lymph nodes
Central lymph node
• Lying in the center of the
axilla in the axillary fat
• Receive lymph from the
above three nodes
• Efferents pass to apical
lymph node
Axillary lymph nodes
Apical lymph node
infraclavicular lymph
nodes
Lying at the apex of the
axilla at the lateral border of
the fist rib
• Receive lymph of the
efferent lymph vessels from
all the other axillary nodes
• The efferents of the apical
nodes form the subclavian
trunk
Axillary lymph nodes
Efferents form subclavian trunk,
the right subclavian trunk joins
the right lymphatic duct; left
Apical ln.
usually drains directly into
thoracic duct
Subclavian trunk
Central ln.
Pectoral ln.
Lateral ln.
Subscapular ln.
Lymphatic drainage of thorax
The lymphatic drainage of
thoracic wall
• To axillary lymph nodes
• To parasternal lymph nodes (along
internal thoracic vessels)
• To intercostals lymph nodes from
deeper structures
• The lymphatic and venous drainages of the breast are of great
importance in the spread of carcinoma.
• About three quarters of the lymphatic drainage is to the axillary nodes:
(1) Lymphatics pass around the edge of the pectoralis major and reach
the pectoral group of axillary nodes;
• (2) routes through or between the pectoral muscles may lead directly to
the apical nodes of the axilla;
• (3) lymphatics follow the blood vessels through the pectoralis major
and enter the parasternal (internal thoracic) nodes;
• (4) connections may lead across the median plane and hence to the
contralateral breast;
• (5) lymphatics may reach the sheath of the rectus abdominis and the
subperitoneal and subhepatic plexuses.
• It should be noted that free communication exists between nodes
below and above the clavicle and between the axillary and cervical
nodes.
lymph nodes of the thorax
• Pulmonary ln. lie in the angles of
bifurcation of branching lobar bronchi
• Bronchopulmonary hilar ln. －
lie in the hilums of the lung
• Tracheobronchial ln. －situated
above or below the bifurcation of
trachea
• Paratracheal ln. －along each side
of the trachea
lymph nodes of the thorax
• Anterior mediastinal lymph
node
– Lies anterior to the large blood vessels of
thoracic cavity and pericardium
– The efferents unite with those of
paratracheal lymph nodes and parasternal
lymph nodes to form the right and left
bronchomediastinal trunks
– The left bronchomediastinal trunk
terminates in thoracic duct, and right in
the right lymphtic duct
• Posterior mediastinal lymph
nodes lie along the esophagus and
thoracic aorta
Lymph nodes of lower limb
Popliteal ln.
• Embedded in the fatty connective
tissue of popliteal fossa
• Receive superficial lymphatic
vessels from posterolateral part of
calf, and from deep lymphatic
vessels accompanying anterior and
posterior tibia a.
• Efferents pass to the deep inguinal
ln.
Lymph nodes of lower limb
Superficial inguinal lymph nodes
Superior group:
– Lies just distal to the inguinal ligament
– Receive lymph vessels from anterior abdominal
wall below umbilicus, gluteal region, perineal
region, external genital organs
•
Inferior group:
– Lies vertical along the terminal great saphenous
v.
– Receives all superficial lymph vessels of lower
limb, except for those from the posterolateral
part of calf
– Efferent vessels drain into the deep inguinal ln.
or external iliac ln.
Lymph nodes of lower limb
Deep inguinal lymph nodes
• Lie medial to the femoral v.
• Receive deep lymph vessels of
lower limb, perineal region, and
efferent vessels from the
superficial inguinal ln.
• Drain into the external iliac ln.
Lymph nodes of pelvis
•
•
•


•
Internal iliac lymph node
– Surround internal iliac vessels
– Receive afferents from pelvic viscera,
perineum, buttock and back of thigh
External iliac lymph nodes
– Lie along external iliac artery
– Receive afferents from lower limb and some
parts of pelvic viscera
Sacral lymph node
locate along middle sacral a. and lateral sacral a.
Receive lymph from posterior pelvic
wall ,rectum,prostate or uterus
Common iliac lymph node
– Lie along common iliac artery
– Receive afferents from all the above nodes
– Efferent pass to lumbar lymph node
Lymph nodes of abdomen
Lymphatic drainage of abdominal
wall
• To axillary lymph node from region
above umbilicus
• To superficial inguinal lymph node from
region below umbilicus
• To lumbar lymph node from post wall of
abdomen
Lymph nodes of abdomen
Lymphatic drainage of
abdominal viscera
• Lumbar lymph nodes
– Lie on posterior abdominal wall,
along the abdominal aorta and
inferior vena cava
– Receive lymph from kidneys,
suprarenal glands, testes,
ovaries, fundus of uterus,
uterine tubes, and common iliac
nodes
– Right and left lumbar trunks
formed by efferent vessel
– Paired viscera－drain to the
lumbar lymph nodes
Lymph nodes of abdomen
• Right and left gastric ln. lie along
the same vessels and finally to the
celiac ln.
• Right and left gastroomental ln.
lie along the same vessels, the
former drain into subpyloric ln.,
the latter drain into splenic ln.
• Suprapyloric and subpyloric ln.
receive lymphatics from pyloric
part and finally to the celiac ln.
• Splenic ln. receive lymphatics
from fundus and left third of
stomach, and finally to the celiac
ln.
• Celiac lymph nodes
－situated around the
celiac trunk
Lymph nodes of abdomen
• Superior mesenteric
lymph node －situated
around superior
mesenteric a.
• Inferior mesenteric
lymph node －situated
around inferior
mesenteric a.
• Intestinal trunk －
formed by efferent
vessel of celiac, superior
and inferior lymph nodes
Thymus
Featrues
Consists of two elongated
lobes
Is large organ in the fetus
Occupies the thoracic
cavity behind the sternum
Secrete lymphopoietin
Thymus
The thymus is partly in the neck
and partly in the thorax. It
comprises one to three lobes, each
of which consists of numerous
lobules containing lymphocytes,
which are important in the
development and maintenance of
the immune system. The cervical
part of the thymus lies on the
anterior and lateral sides of the
trachea, whereas the thoracic part
lies posterior to the superior
portion of the sternum. The organ
has a profuse blood supply and
lymphatic drainage. The thymus
reaches its greatest size at puberty
and then begins to regress. Much
of its substance is replaced by fat
and fibrous tissue, but thymic
tissue never disappears completely.
Function:to develop lymph
cell
• Shape
Spleen
– The largest single mass of
lymphoid tissue in the body
– Reddish in color
• Location:
– lies in the left hypochondriac region
(between stomach and diaphragm)
deep to the 9th to 11th rib
– its long axis corresponds roughly to
the 10th rib
– Its lower pole extends forward only
as far as the midline and cannot be
palpated on clinical examination
• Two surfaces
Spleen
– Diaphragmatic: smooth, convex
– Visceral: concave, hilum of spleen
• Two extremities
– Anterior－wider
– Posterior－rounder
• Two border
– Superior－has 2-3 splenic notch, which
serve as a landmark on palpation when it is
enlarge; normally it is not palpable
– Inferior－rounder
Spleen
 Function
Erythrocyte storage
Phagocytosis
Cytopoiesis
Immune responses