Venules
The minute vessels that collect blood from the capillary plexuses and join together to form veins.
Leukocytes
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
Endothelium, Lymphatic
Unbroken cellular lining (intima) of the lymph vessels (e.g., the high endothelial lymphatic venules). It is more permeable than vascular endothelium, lacking selective absorption and functioning mainly to remove plasma proteins that have filtered through the capillaries into the tissue spaces.
Arterioles
The smallest divisions of the arteries located between the muscular arteries and the capillaries.
Mesenteric Veins
Leukocyte Rolling
Movement of tethered, spherical LEUKOCYTES along the endothelial surface of the microvasculature. The tethering and rolling involves interaction with SELECTINS and other adhesion molecules in both the ENDOTHELIUM and leukocyte. The rolling leukocyte then becomes activated by CHEMOKINES, flattens out, and firmly adheres to the endothelial surface in preparation for transmigration through the interendothelial cell junction. (From Abbas, Cellular and Molecular Immunology, 3rd ed)
L-Selectin
Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.
Mesentery
P-Selectin
Capillary Permeability
The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.
Splanchnic Circulation
Microscopy, Video
Endothelium, Vascular
Capillaries
The minute vessels that connect the arterioles and venules.
Lymph Nodes
They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.
Receptors, Lymphocyte Homing
Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.
Endothelium
A layer of epithelium that lines the heart, blood vessels (ENDOTHELIUM, VASCULAR), lymph vessels (ENDOTHELIUM, LYMPHATIC), and the serous cavities of the body.
Corrosion Casting
A tissue preparation technique that involves the injecting of plastic (acrylates) into blood vessels or other hollow viscera and treating the tissue with a caustic substance. This results in a negative copy or a solid replica of the enclosed space of the tissue that is ready for viewing under a scanning electron microscope.
Mucoproteins
Erythrocyte Aggregation
The formation of clumps of RED BLOOD CELLS under low or non-flow conditions, resulting from the attraction forces between the red blood cells. The cells adhere to each other in rouleaux aggregates. Slight mechanical force, such as occurs in the circulation, is enough to disperse these aggregates. Stronger or weaker than normal aggregation may result from a variety of effects in the ERYTHROCYTE MEMBRANE or in BLOOD PLASMA. The degree of aggregation is affected by ERYTHROCYTE DEFORMABILITY, erythrocyte membrane sialylation, masking of negative surface charge by plasma proteins, etc. BLOOD VISCOSITY and the ERYTHROCYTE SEDIMENTATION RATE are affected by the amount of erythrocyte aggregation and are parameters used to measure the aggregation.
Cell Movement
Selectins
Transmembrane proteins consisting of a lectin-like domain, an epidermal growth factor-like domain, and a variable number of domains that are homologous to complement regulatory proteins. They are important cell adhesion molecules which help LEUKOCYTES attach to VASCULAR ENDOTHELIUM.
Cell Adhesion Molecules
Chemokine CCL21
Blood Flow Velocity
Mice, Inbred C57BL
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
E-Selectin
Cell adhesion molecule and CD antigen that mediates neutrophil, monocyte, and memory T-cell adhesion to cytokine-activated endothelial cells. E-selectin recognizes sialylated carbohydrate groups related to the Lewis X or Lewis A family.
Integrin alpha4
Glycocalyx
The carbohydrate-rich zone on the cell surface. This zone can be visualized by a variety of stains as well as by its affinity for lectins. Although most of the carbohydrate is attached to intrinsic plasma membrane molecules, the glycocalyx usually also contains both glycoproteins and proteoglycans that have been secreted into the extracellular space and then adsorbed onto the cell surface. (Alberts et al., Molecular Biology of the Cell, 3d ed, p502)
Capillary Resistance
The vascular resistance to the flow of BLOOD through the CAPILLARIES portions of the peripheral vascular bed.
Microvessels
Lymphocytes
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.