LeechLeeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having ring markings that do not correspond with their internal segmentation.
Purkinje fibersThe Purkinje fibers (pɜːrˈkɪndʒi ; ˈpurkɪɲɛ; Purkinje tissue or subendocardial branches) are located in the inner ventricular walls of the heart, just beneath the endocardium in a space called the subendocardium. The Purkinje fibers are specialized conducting fibers composed of electrically excitable cells. They are larger than cardiomyocytes with fewer myofibrils and many mitochondria. They conduct cardiac action potentials more quickly and efficiently than any of the other cells in the heart's electrical conduction system.
Vasa vasorumVasa vasorum are small blood vessels that comprise a vascular network supplying the walls of large blood vessels, such as elastic arteries (e.g., the aorta) and large veins (e.g., the venae cavae). The name derives . Occasionally two different singular forms are seen: vasa vasis () and vas vasis (). Studies conducted with 3D micro-CT on pig and human arteries from different vascular beds have shown that there are three different types of vasa vasorum: Vasa vasorum internae, that originate directly from the main lumen of the artery and then branch into the vessel wall.
PneumaPneuma (πνεῦμα) is an ancient Greek word for "breath", and in a religious context for "spirit" or "soul". It has various technical meanings for medical writers and philosophers of classical antiquity, particularly in regard to physiology, and is also used in Greek translations of ruach רוח in the Hebrew Bible, and in the Greek New Testament. In classical philosophy, it is distinguishable from psyche (ψυχή), which originally meant "breath of life", but is regularly translated as "spirit" or most often "soul".
Thoracic ductIn human anatomy, the thoracic duct (also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal) is the larger of the two lymph ducts of the lymphatic system (the other being the right lymphatic duct). The thoracic duct usually begins from the upper aspect of the cisterna chyli, passing out of the abdomen through the aortic hiatus into first the posterior mediastinum and then the superior mediastinum, extending as high up as the root of the neck before descending to drain into the systemic (blood) circulation at the venous angle.
Exercitatio Anatomica de Motu Cordis et Sanguinis in AnimalibusExercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (Latin, 'An Anatomical Exercise on the Motion of the Heart and Blood in Living Beings'), commonly called De Motu Cordis, is the best-known work of the physician William Harvey, which was first published in 1628 and established the circulation of blood throughout the body. It is a landmark in the history of physiology, with Harvey combining observations, experiments, measurements, and hypotheses in an extraordinary fashion to arrive at his doctrine.
VenuleA venule is a very small vein in the microcirculation that allows blood to return from the capillary beds to drain into the venous system via increasingly larger veins. Post-capillary venules are the smallest of the veins with a diameter of between 10 and 30 micrometres (μm). When the post-capillary venules increase in diameter to 50μm they can incorporate smooth muscle and are known as muscular venules. Veins contain approximately 70% of total blood volume, while about 25% is contained in the venules.
Smallest cardiac veinsThe smallest cardiac veins (also known as the Thebesian veins (named for Adam Christian Thebesius)) are small, valveless veins in the walls of all four heart chambers that drain venous blood from the myocardium directly into any of the heart chambers. They are most abundant in the right atrium, and least abundant in the left ventricle. The smallest cardiac veins vary greatly in size and number. Those draining the right atrium have a lumen of up to 2 mm in diameter, whereas those draining the right ventricle have lumens as small as 0.
Coronary stentA coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in the treatment of coronary heart disease. It is used in a procedure called percutaneous coronary intervention (PCI). Coronary stents are now used in more than 90% of PCI procedures. Stents reduce angina (chest pain) and have been shown to improve survival and decrease adverse events in an acute myocardial infarction. Similar stents and procedures are used in non-coronary vessels (e.
EmbolizationEmbolization refers to the passage and lodging of an embolus within the bloodstream. It may be of natural origin (pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced (therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells. In the cancer management application, the embolus, besides blocking the blood supply to the tumor, also often includes an ingredient to attack the tumor chemically or with irradiation.
