LYMPHATIC VESSEL
(anatomical view)
-Amirah Nu’aimi Binti Zakaria
-Siti Sarah Amiza Binti Md Amin
LYMPHATIC VESSEL
• A vessel that carries fluid only away from tissues. This fluid is a pale, watery
substance known as lymph.
• Act as reservoirs for plasma and other substances including cells that have
leaked from the vascular system and transport lymph fluid back from the tissues to
the circulatory system.
• In anatomy, lymph vessels are lined by endothelial cells, and have a thin layer
of smooth muscles, and adventitia that bind the lymph vessels to the surrounding
tissue.
•There are three main types of lymphatic vessels which are lymph capillaries,
lymphatics and lymph ducts.
• There is no pump in the lymphatic system like the heart in the cardiovascular
system. The pressure gradients to move lymph through the vessels come from :
1.
the skeletal muscle action,
2.
respiratory movement,
3.
contraction of smooth muscle in vessel walls.
LYMPHANGION
• Is a functional unit of a lymph vessel which is the segment between
two valves.
• Have valves to prevent backflow of blood.
• Smooth muscles in the walls of the lymphatic vessels cause the
angions to contract sequentially to aid the flow of lymph toward the
thoracic region.
LYMPHATIC CAPILLARIES
• The smallest lymph vessels are the lymph capillaries, which
begin in the tissue spaces as blind-ended sacs.
• Found in all regions of the body except the bone
marrow, central nervous system, and tissues, such as the
epidermis, that lack blood vessels.
• Mainly concerned with absorption of interstitial fluid from the
tissues.
LYMPHATICS
• Lymph vessels that carry
lymph to a lymph node are
called the afferent lymph
vessel.
• One that carries it from
a lymph node is called the
efferent lymph vessel,
from where the lymph
may travel to another
lymph node, may be
returned to a vein, or may
travel to a larger lymph
duct.
LYMPHATIC DUCTS
Right Lymphatic Duct
Thoracic Duct
Collects lymph from the right side of the Collects all the lymph from the hind limbs
head, the right neck, the right upper limb and alimentary canal.
and the right side of the chest.
Also receives the left cervical duct which
collects lymph from the left forelimb, left
side of the neck and chest.
Empties into the venous system at the Opens into the venous system at the
right subclavian vein and internal jugular junction of the left internal jugular vein
vein.
and subclavian vein.
• Lymph ducts drain the
lymph into one of
the subclavian and internal
jugular veins and thus
return it to
general circulation
Histology of Lymph Vessels
BY
KHIRROL NIZAM D11A014
NUR ALYAA D11023
• found in all tissues except the CNS, cartilage, bone and
bone marrow, thymus, teeth, and placenta
• difficult to demonstrate satisfactorily in normal tissues
• frequently collapse to the point of invisibility during
tissue processing
• easily visualized and studied during pathological
processes (e.g., inflammation)
• blind-ended lymphatic capillaries which coalesce to
form lymphatic vessels and finally empty into the
circulation via the lymphatic ducts (thoracic and right
lymphatic).
•convey fluids from the tissues to the
bloodstream
•in contrast to blood vessels, which carry
blood to and from tissues, lymphatic
vessels are unidirectional due to the
presence of valves which direct the flow of
lymph
•more permeable than blood vessels
•lymphatic capillaries – smallest lymphatic
vessels
•numerous in loose connective tissues of
the skin and in mucous membranes
•converge into larger vessels that
ultimately unite to form two main channels
that empty lymph into the blood stream
•Top photo - small lymphatic vessel next to
a small vein - not contain RBCs, but a few
lymphocytes
•Bottom photo - a valve present within the
lymphatic vessel
Slide : spermatic cord.
•lymphatic vessels of the
spermatic cord
•like the veins
(pampiniform plexus) of
the spermatic cord, these
lymphatic vessels have
unusually thick walls
•note the valve leaflets of
this vessel
Dilated Lymphatic Vessel
•Fibrous connective tissue is full
of little endothelially-lined, thinwalled channels
•tubes of endothelium
•Easy to see when distended draining excess tissue fluid.
•section of fibrous tissue from a
patient with some extra tissue
fluid that needed draining
see:
•big dilated lymphatic
•less-filled lymphatic
•the endothelium of both
lymphatic
Another Big Lymphatic
dilated lymphatic in the
serosa of the colon in a
person who had peritonitis
See:
•big lymphatic
•endothelial cell nuclei
•Valve
•pus in the left lower corner
•smooth muscle at the top
A Slender Lymphatic
Vessel
•lymphatic vessel under a
bit of ciliated epithelium
•from oviduct
•no valves visible here
found:
•the lymphatic vessel
•its endothelium
•the little blood vessels
near it
A Collapsed Lymphatic
Vessel
•dense irregular
connective tissue
Cancer Cells in a
Lymphatic Vessel
•cancer cells are easy to spot
even at low power
•their nuclei are very large
•most of the common cancers
spread via the lymphatic
vessels
•this is a lymphatic with
cancer in it
See:
•the large lymphatic
•cancer cells in the center of
lymphatic vessel
•reinforced by a bit of smooth
muscle
Lymphatic Channel in
Inflammation
•Inflammation is the stereotyped tissue
response to injury
•the vessels let protein leak out
•If the tissue damage is severe enough, some
of the local structural proteins may be
solubilized as well
•Normally the fluid in the lymphatic vessels is
scanty and contains very little protein
•This changes when a lymphatic vessel drains
an area where soluble proteins have
accumulated in an area because of
inflammation.
This is a lymphatic vessel draining an inflamed
area
•lymphatic vessel
•some inflammatory cells in its lumen the
protein-rich fluid in its lumen
•the edema fluid in the tissue surrounding the
lymphatic vessel
Sections of small intestine
•villi extending into the lumen
of the jejunum
•In some of the villi - fairly
large open spaces, which are
surrounded by a layer of
flattened endothelial cells
•not contain any red blood
cells
•these openings represent the
blind end of lymph capillaries
which originate in the villi.
•lacteals - is derived from the
milky appearance of the
lymph - suspended lipid
droplets which enter these
lymph capillaries.
LYMPHATIC VESSEL-LACTEAL
BY NUR FARHANA OTHMAN
D11A026
• Present in the gastrointestinal tract
• Most nutrients that are absorbed by the SI will be
carried by portal vein to the liver
• Absorption of fat takes place in the duodenum
and is transported into lymphatic system
• First, fat droplets which consists mainly of
triglycerides will be emulsified by bile salts
• Then, lipase produced by pancreas will digest the
emulsified fat into fatty acids and monoglyceride
• The fatty acids and monoglycerides leave the
micelle and enter the epithelial cell.
• Inside the epithelial cell the fatty acids and
monoglycerides combine with protein to form
chylomicrons (lipid + proteins).
• Lastly, the chylomicrons are secreted into the
lymphatic system
Lymphatic Vessels in
Physiological View
Nur Farhana binti Othman
Nur Athirah binti Mohd Azhar
How does it flow
• Moves in one-way (towards the heart)
• Assisted by muscular contractions, rhythmic
contraction of lymphatic vessel walls and
pressure changes in thoracic cavity during
respiration
• Have valves to prevent backflow
• Excess fluid that is that is drained into blindended lymph capillaries is called the lymph.
• „The lymph starts at the capillary beds, where
they enter the lymph capillaries and later
merges with the lymph vessels
• Lymph vessels have smooth muscles around
them that contract, keeping the lymph flow
upward
Lymph capillaries
Left and right
thoracic duct
Left and right
subclavian vein
Lymph nodes
Lymphatic
vessels