Lymph nodes are oval shaped structures scattered throughout the body along lymph vessels. They range in size from 1-25mm. Lymph nodes contain immune cells like B cells, T cells, and macrophages. They have an outer capsule and inner medulla and cortex regions. Lymph flows into nodes through afferent vessels and is filtered by macrophages and lymphocytes before exiting through efferent vessels. This allows immune cells time to identify foreign substances and mount a response. Major lymph node groups are found in the neck, armpits, groin, and abdomen. Lymph nodes help protect the body by removing pathogens and producing immune cells.

1. ANATOMY OF LYMPH NODE
PRESENTED BY
HUSSEIN ALI HUSSEIN AL-HCHAIMI
MSC. STUDENT
ANESTHESIA DEPARTMENT
TUMS

2. -- Oval, bean shaped structures scattered throughout body along
lymph vessels.
--Usually 1-25 mm in length, but they can be larger.
–May be deep or superficial.
--Greatest concentration near groin, axilla, neck, thorax, and
along gut tube in abdomen.
In generally...

3.  Distributed widely throughout the body including
the armpit and stomach and linked by lymphatic
vessels .
 Lymph nodes are major sites of B, T, and other immune
cells .
 Large clusters in inguinal , axilliary , cervical regions.

4. ANATOMICAL
PICTURES

8. STRUCTURE OF A LYMPH NODE
➢Outermost is the covering called capsule
composed of fibrous connective tissue
 Capsule contains the
parenchyma or stroma
 Stroma is differentiated
into cortex & medulla
Trabeculae extend from
cortex to medulla

10. Cortex
Medulla
 inner germinal
center is the site of B-
cell proliferation
inner medulla
medullary cords of
lymphocytes,
macrophages, plasma
cells.
●outer cortex
● - filled with lymph follicles
-outer edge of follicle contains more T cells

11. CYTOLOGY OF THE
LYMPH NODE
The normal or reactive lymph node is composed of
➢ Transient B and T lymphocytes
➢ Antigen processing and presenting cells
➢ Replicating B and T lymphocytes (in response to
antigen)
➢ Persistent and transient final effector cells
➢ Macrophages

12.  B lymphocytes are located primarily in
the follicles and perifollicular areas
 T lymphocytes are found primarily in the
interfollicular or paracortical areas of the
lymph node.

13. •Macrophages and lymphocytes reside in the outer
("cortex") region of a node.
●Afferent (entering) vessels bring lymph in.
●Lymph first enters into a large subcapsular sinus &
then into many small sinuses.
●Throughout the node are lymph sinuses
crisscrossed by reticular fibers

14. •The node acts as
a “settling tank,”
because there are
fewer efferent
vessels, lymph
stagnates
somewhat in the
node.
•Macrophages reside on these fibers where
they phagocytise foreign matter.

15. This allows lymphocytes and macrophages time
to carry out their protective functions
Reticular fibers filter and trap damaged cells,
microorganisms, foreign substances, tumor cells.
 Macrophages phagocytize some, lymphocytes
destroy some by immune defenses.
"Medulla" is the inner collecting area.
Efferent (exiting) vessel leaves at the "hilus.

17. DISTRIBU
TION

18. Lymph nodes of clinical importance have been put
under 5 main groups :
➢ Cervical groups
➢ Axillary groups
➢ Inguinal groups :
>Iliac
 Trachiobronchial
 Aortic

20. CERVICAL GROUPS
Right & left groups
each divided into: horizontal (circular) and
vertical
 The horizontal group include:
 sub-mental
 sub-mandibular
 parotid
 pre-auricular
 post-auricular
 occipital

21. CONT…
 The vertical group include:
 superficial (along external jugular vein)
 deep (along internal jugular vein)
 Pre-laryngeal
 Pre-tracheal
 Para-tracheal

22. AXILLARY GROUPS
 Right & left groups
 each divided into 5 groups:
 Anterior (pectoral)
 posterior (sub-scapular)
 medial (along chest wall)
 lateral
 central

24.  Horizontal group lies along the inguinal
ligament (both above and over)
 Vertical group is beside the great
saphenous vein in the proximal thigh.
 Iliac nodes : above and deep to inguinal
ligament
Inguinal groups

26.  The human body has two small groups which
are :
 Epitrochlear lymph nodes .
 Popliteal lymph nodes : these nodes are located
posterior to the knee joint .

27. 3 cm proximal to the medial humeral
epicondyle, in the groove between the
biceps and triceps brachii.
Epitrochlear nodes

28. LYMPH NODES FUNCTION
 Help protect the body by removing
foreign material (bacteria and tumor
cells).
 Protect the body by producing
lymphocytes.
 Filter lymph fluid to trap foreign

29. THANK
YOU.....