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Lymph Glands (lymphoglandulae) • After initial maturation in the primary immune organs, "virgin" B and T lymphocytes are released into the peripheral blood and home to specific sites within the lymph node (and the other secondary organs), controlled by incompletely understood homing receptors. • The sites of B cell homing include: 1. The primary and secondary follicles of the lymph node cortex-the sites of antigen presentation to B cells, and subsequent proliferation and differentiation in response to same. 2. The medullary cords, where plasma cells aggregate, and release their immunoglobulins into the efferent lymph.
Lymph Glands (lymphoglandulae) • The site of T cell homing is the paracortex. • Normal lymphocytes recirculate, passing from blood into and through the lymph nodes, and then into efferent lymphatics, surveilling for the presence of the antigen for which they have a unique and specific receptor on their surface • If this antigen is not present, the lymphocytes leave the node. • Virgin lymphocytes have a finite lifespan, numbered in weeks, unless they come in contact with antigen.
Lymphatic circulation • Lymph circulates to the lymph node via afferent lymphatic vessels and drains into the node just beneath the capsule in a space called the subcapsular sinus. • The subcapsular sinus drains into trabecular sinuses and finally into medullary sinuses. • The sinus space is criss-crossed by the pseudopods of macrophages which act to trap foreign particles and filter the lymph. • The medullary sinuses converge at the hilum and lymph then leaves the lymph node via the efferent lymphatic vessel towards either a more central lymph node or ultimately for drainage into a central venous subclavian blood vessel, most via Virchow's node and Ductus Thoracicus.
The Lymph • Found only in the closed lymphatic vessels. • It’s transparent, colorless, or slightly yellow, watery fluid of specific gravity about 1.015; it closely resembles the blood plasma, but is more dilute • Lymph should be distinguished from “tissue fluid” which is found outside the lymphatic vessels in the tissue spaces.
Lymph nodes of the arm • These drain the whole of the arm, and are divided into two groups, superficial and deep. • Deep lymph glands of the arm: These comprise the axillary glands, which are 20-30 individual glands and can be subdivided into: ◦ Lateral glands ◦ Anterior or pectoral glands ◦ Posterior or subscapular glands ◦ Central or intermediate glands ◦ Medial or subclavicular glands • Superficial lymph glands of the arm: ◦ Supratrochlear glands: Situated above the medial epicondyle of the humerus, medial to the basilic vein, they drain the C7 and C8 dermatomes. ◦ Deltoideopectoral glands: Situated between the pectoralis major and deltoidmuscles inferior to the clavicle.
Lymph Nodes of The Leg Thesuperficial inguinal lymph nodes:- • They receive as afferents lymphatic vessels from the following:• Integument of the penis• Scrotum• Perineum• Buttock• Abdominal wall below the level of the umbilicus• Vulva• Anus (below the pectinate line)• The lower extremity (foot, leg and thigh) • They are divided into three groups:• Supramedial or Superomedial• Superolateral• Inferior
1. Supromedial superficial inguinal2. Superolateral superficial inguinal3. Inferior superficial inguinal4. Deep inguinal lymph nodes
Lymph Nodes of The Leg The deep inguinal lymph nodes:- • The deep inguinal lymph nodes drain superiorly to the external iliac lymph nodes, then to the pelvic lymph nodes and on to the para-aortic lymph nodes.
1. Supromedial superficial inguinal2. Superolateral superficial inguinal3. Inferior superficial inguinal4. Deep inguinal lymph nodes
THANKS Dr. Ryan AL.Ghanemi