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Active transport is used to move most substances between the blood vessels and the osteocytes. [1] Haversian canals are contained within osteons, which are typically arranged along the long axis of the bone in parallel to the surface. The canals and the surrounding lamellae (8-15) form the functional unit, called a Haversian system, or osteon.
The endodermis is the boundary between the cortex and the stele. In many seedless plants, such as ferns, the endodermis is a distinct layer of cells immediately outside the vascular cylinder (stele) in roots and shoots. In most seed plants, especially woody types, the endodermis is present in roots but not in stems.
They usually run at obtuse angles to the Haversian canals (which run the length of the bone) and contain anastomosing vessels between haversian capillaries. They were named after German physiologist Alfred Volkmann (1800–1878). The perforating canals, with the blood vessels, provide energy and nourishing elements for osteons.
The Haversian canal contains the bone's blood supplies. The boundary of an osteon is the cement line. Each Haversian canal is surrounded by varying number (5-20) of concentrically arranged lamellae of bone matrix. Near the surface of the compact bone, the lamellae are arranged parallel to the surface; these are called circumferential lamellae.
Some of the mesoderm derivatives include the muscle (smooth, cardiac, and skeletal), the muscles of the tongue (occipital somites), the pharyngeal arches muscle (muscles of mastication, muscles of facial expressions), connective tissue, the dermis and subcutaneous layer of the skin, bone and cartilage, dura mater, the endothelium of blood ...
The dental canaliculi (sometimes called dentinal tubules) are the blood supply of a tooth. [4] Odontoblast process run in the canaliculi that transverse the dentin layer and are referred as dentinal tubules. [5] The number and size of the canaliculi decrease as the tubules move away from the pulp and toward the enamel or cementum.
The efferent lymphatic vessel commences from the lymph sinuses of the medullary portion of the lymph nodes and leave the lymph nodes at the hilum, either to veins or greater nodes. It carries filtered lymph out of the node. Efferent lymphatic vessels are also found in association with the thymus and spleen. This is in contrast to afferent ...
Blood vessels function to transport blood to an animal's body tissues. In general, arteries and arterioles transport oxygenated blood from the lungs to the body and its organs, and veins and venules transport deoxygenated blood from the body to the lungs. Blood vessels also circulate blood throughout the circulatory system.