The lymph nodes
Lymph nodes (nodi lymphatici) - the most numerous bodies immune system. In the body of their number reaches 500. All of them are on the path of lymph flow and cutting, contribute to its further advancement. Their main function is the barrier-filtration, that is, inhibition of bacteria and other foreign particles from lymph flow path. In addition, lymph nodes, perform hematopoietic function, taking part in the formation of lymphocytes, and immunotsitopoeticheskuyu function to form plasma cells that produce antibodies. The shape of lymph nodes can be very diverse: spherical, ovoid, elongated or bean. Size ranges from 25 to 50 mm.
The lymph node has a convex side, which in the number of 4-6 sets bearing the lymphatic vessels (vas lymphaticum afferena), that is supplying the lymph to the lymph nodes, and the concave side, called a gateway node (hilum). Through the gate to enter the node feeding his arteries and nerves. And some of them go efferent lymph vessels (vas lymphaticum efferens), leading out of the lymph node, and veins. Covers a lymph node capsule (capsula), formed by connective tissue with a mixture of smooth muscle fibers, which provides the ability to shrink the site. From the capsule interior node sent the so-called crossbars, or trabeculae (trabecula), which together with the reticulum cells and fibers involved in the formation of the stroma. In the hinges of the stroma are the cellular elements of lymph nodes, predominantly lymphocytes. The intervals between the trabeculae are filled with lymphoid tissue. In the convex side of the host cells are condensed to form cortex (cortex), which is located medially from the medulla (medulla). It contains lymph-filled sinuses that surround the fenced off from the elements of the cortex of lymphoid tissue, brain called strands. Inside the lymph node system circulates through sinuses. Bearing lymph vessels supplying the marginal sinus, which is a gap between the capsule and cortical substance. It connects to the intermediate cortical sinuses (sinus corticalis), from which the lymph enters the brain intermediate sinuses (sinus medullaris). Cerebral sinuses, uniting to form the portal sinus, through which the lymph enters the gate node, and then - in the efferent lymph vessels. In the cortex are lymphoid nodules (nodulus lymphaticus), which lie closer to the capsule and have a rounded shape. Some of these nodules is reactive, or light-colored centers. Lymphoid tissue that fills the spaces between the bundles, called mezhuzelkovoy, and lymphoid tissue, located medially from the nodules - parakortikalnoy zone (paracortex).
|In Fig. 241.
The structure of the lymph node
1 - bringing lymphatic vessel;
2 - scavenging lymphatic vessels;
3 - cortex;
4 - artery;
5 - Vienna;
6 - capsule;
7 - medulla;
8 - Gates lymph node;
9 - trabeculae;
10 - parakortikalnaya zone;
11 - Interim cerebral sinus;
12 - intermediate cortical sinus;
13 - lymphatic nodule
Classification of lymph nodes is carried out on areas of the body and the ratio of cortical and medullary substances that affect their form. Lymph nodes are also divided into visceral, somatic, parietal, and mixed, depending on area limfosbrosa. In the visceral lymph nodes collected from the internal organs, as evidenced by their name: tracheobronchial, mesenteric, and others physical units, which include, for example, popliteal and elbow lymph nodes, lymph comes from the musculoskeletal system. From the walls of the cavities is sent to the parietal lymph lymph nodes. Mixed-called nodes, which collect lymph from the body and the elements of catfish (deep cervical lymph nodes).
a., aa. — arteria, arteriae (artery, the artery)
lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)
m., mm. — musculus, musculi (muscle, the muscle)
n., nn. — nervus, nervi (nerve, the nerve)
r., rr. — ramus, rami (branch)
s. — seu (or)
v., vv. — vena, venae (vienna)