Some notes about the anatomy of lymphatic system in general

1. Anatomy of lymphatic system
Dr. Mohammed Mahmoud Mosaed

2. The lymphatic system
• The lymphatic system consists of lymphatic tissues and
lymphatic vessels.
• Functions: It is essential for the immunologic defenses of
the body against bacteria and viruses.

3. Lymphatic tissues
• Lymphatic tissues are a
type of connective tissue
that contains large
numbers of lymphocytes.
• Organs or structures of
lymphatic tissue: the
thymus, the lymph nodes,
the spleen, and the
lymphatic nodules.

4. Lymphatic vessels
• Lymphatic vessels are tubes that assist the
cardiovascular system in the removal of
tissue fluid from the tissue spaces of the
body
• Lymphatic vessels are found in all tissues and
organs of the body except the central
nervous system, the eyeball, the internal ear,
the epidermis of the skin, the cartilage, and
the bone.

5. Characteristics of lymph vessels
• Lymph vessels have a beaded
appearance because of the
presence of numerous valves
along their course.
• They form an afferent and
efferent.
• Afferent vessels carry lymph
to a lymph node
• efferent vessels. transport
lymph away from a node.

6. Lymph
• Lymph is the name given to
tissue fluid once it has entered
a lymphatic vessel.
• Lymph is a clear watery fluid
that contains:
• The plasma proteins.
• larger particles, e.g. bacteria
and cell debris
• lymphocytes, which circulate in
the lymphatic system.
• In the small intestine, fats
absorbed into the lymphatics
give the lymph (now called
chyle), a milky appearance

7. Lymph capillaries
• Lymph capillaries are a
network of fine vessels that
drain lymph from the tissues.
• These originate as blind end
tubes in the interstitial spaces
• The capillaries are in turn
drained by small lymph
vessels, which unite to form
large lymph vessels.
• lymphatic capillaries (known
as lacteals in the small
intestine)

8. Major lymphatic ducts
• Lymph vessels becomes larger as they join
together, eventually forming two large ducts:
• The thoracic duct
• Right lymphatic duct
• Both ducts empty lymph into subclavian
veins.

9. Large lymphatic duct
• Thoracic duct
• This duct begins at the cisterna chyli, which is a
dilated lymph channel situated in front of the
bodies of the first two lumbar vertebrae. The
duct is about 40 cm long and opens into the
left subclavian vein in the root of the neck. It
drains lymph from both legs, the pelvic and
abdominal cavities, the left half of the thorax,
head and neck and the left arm.
• Right lymphatic duct
• This is a dilated lymph vessel about 1 cm long.
It lies in the root of the neck and opens into
the right subclavian vein. It drains lymph from
the right half of the thorax, head and neck and
the right arm.

11. Lymph node
• Before lymph is returned to the bloodstream, it
passes through the lymph nodes.
• Special characteristics of lymph node
• The lymph node is the only lymphoid organ
present in the path of lymphatic vessels.
• The only lymphoid organ, having afferent and
efferent lymphatic vessels
• The only lymphoid organ, having lymphatic
sinuses.
• The only organ which filters the lymph.

13. Main groups of lymph nodes present
in human body
• Cubital (supratrochlear) Lymph Nodes
• Axillary Lymph Nodes
• Lymph nodes of Head and Neck
• Lymph Nodes of the thoracic Region
• Intestinal Lymph Nodes
• Iliac Nodes
• Inguinal Lymph Nodes
• Popliteal Lymph Nodes