Internodal segment | |
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Details | |
Part of | Axon of nerve fiber |
System | Nervous system |
Identifiers | |
Latin | segmentum internodale |
TH | H2.00.06.2.03028 |
Anatomical terms of microanatomy |
An internodal segment (or internode) is the portion of a nerve fiber between two Nodes of Ranvier. The neurolemma or primitive sheath is not interrupted at the nodes, but passes over them as a continuous membrane.
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function.
The axilla is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superiorly by the imaginary plane between the superior borders of the first rib, clavicle and scapula, medially by the serratus anterior muscle and thoracolumbar fascia, anteriorly by the pectoral muscles and posteriorly by the subscapularis, teres major and latissimus dorsi muscle.
In human anatomy, the groin, also known as the inguinal region or iliac region, is the junctional area between the torso and the thigh. The groin is at the front of the body on either side of the pubic tubercle, where the lower part of the abdominal wall meets the thigh. A fold or crease is formed at this junction known as the inguinal groove, or crease. This is also the area of the medial compartment of the thigh that contains attachments of the adductor muscles of the hip or the groin muscles. The groin is the common site for a hernia.
The tracheobronchial lymph nodes are lymph nodes that are located around the division of trachea and main bronchi.
The pararectal lymph nodes are lymph nodes that are in contact with the muscular coat of the rectum.
The preaortic lymph nodes lie in front of the aorta, and may be divided into celiac lymph nodes, superior mesenteric lymph nodes, and inferior mesenteric lymph nodes groups, arranged around the origins of the corresponding arteries.
The inferior mesenteric lymph nodes consist of:
The internal iliac lymph nodes surround the internal iliac artery and its branches, and receive the lymphatics corresponding to the distribution of the branches of it, i. e., they receive lymphatics from all the pelvic viscera, from the deeper parts of the perineum, including the membranous and cavernous portions of the urethra, and from the buttock and back of the thigh. The internal iliac lymph nodes also drain the superior half of the rectum, above the pectinate line.
One or two supratrochlear lymph nodes are placed above the medial epicondyle of the humerus, medial to the basilic vein.
The deep cervical lymph nodes are a group of cervical lymph nodes in the neck that form a chain along the internal jugular vein within the carotid sheath.
The inferior deep cervical lymph nodes are one of the two groups of the deep cervical lymph nodes.
The superior deep cervical lymph nodes are the deep cervical lymph nodes that are situated adjacent to the superior portion of the internal jugular vein. They drain either to the inferior deep cervical lymph nodes or into the jugular trunk.
The submental lymph nodes are 2-3 lymph nodes situated in the submental triangle, between the anterior bellies of the digastric muscle and the hyoid bone.
Supraclavicular lymph nodes are lymph nodes found above the clavicle, that can be felt in the supraclavicular fossa. The supraclavicular lymph nodes on the left side are called Virchow's nodes. It leads to an appreciable mass that can be recognized clinically, called Troisier sign.
The superficial cervical lymph nodes are lymph nodes that lie near the surface of the neck.
The buccinator lymph node or nodes are one or more lymph nodes placed on the buccinator opposite the angle of the mouth.
The submandibular lymph nodes, are some 3-6 lymph nodes situated at the inferior border of the ramus of mandible.
The parasternal lymph nodes are placed at the anterior ends of the intercostal spaces, by the side of the internal thoracic artery.
The celiac lymph nodes are associated with the branches of the celiac artery. Other lymph nodes in the abdomen are associated with the superior and inferior mesenteric arteries. The celiac lymph nodes are grouped into three sets: the gastric, hepatic and splenic lymph nodes. They receive lymph from the stomach, duodenum, pancreas, spleen, liver, and gall bladder.
The splenic lymph nodes are found at the splenic hilum and in relation to the tail of the pancreas.
This article incorporates text in the public domain from page 727 of the 20th edition of Gray's Anatomy (1918)