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Jan Evangelista Purkyně
Jan Evangelista Purkyně (; also written Johann Evangelist Purkinje) (17 or 18 December 1787 – 28 July 1869) was a Czech anatomist and physiologist. In 1839, he coined the term ''protoplasm'' for the fluid substance of a cell. He was one of the best known scientists of his time. Such was his fame that when people from outside Europe wrote letters to him, all that they needed to put as the address was "Purkyně, Europe". Biography Purkyně was born in the Kingdom of Bohemia (then part of the Austrian monarchy, now Czech Republic). After completing senior high school in 1804, Purkyně joined the Piarists order as a monk but subsequently left "to deal more freely with science." In 1818, he graduated from Charles University in Prague with a degree in medicine, where he was appointed a Professor of Physiology. He discovered the Purkinje effect, the human eye's much reduced sensitivity to dim red light compared to dim blue light, and published in 1823 description of several en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libochovice
Libochovice (german: Libochowitz) is a town in Litoměřice District in the Ústí nad Labem Region of the Czech Republic. It has about 3,400 inhabitants. Administrative parts Villages of Dubany and Poplze are administrative parts of Libochovice. Geography Libochovice is located about south of Litoměřice. It lies on the Ohře river. It is situated in an agricultural landscape of the Lower Eger Table. History The first written mention of Libochovice is from 1336, when it was described as a market town with a fortress. In 1560, Libochovice became a town. The first Jews came into the town probably in the second half of the 15th century. From the second half of the 16th century there was a strong Jewish community, but most of them died during the Holocaust, and the community was never renewed after the World War II. Sights Libochovice is known for the Libochovice Chateau. It is Rennaisance castle, created by reconstruction of the former Gothic fortress. The castle park was fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piarists
The Piarists (), officially named the Order of Poor Clerics Regular of the Mother of God of the Pious Schools ( la, Ordo Clericorum Regularium pauperum Matris Dei Scholarum Piarum), abbreviated SchP, is a religious order of clerics regular of the Catholic Church founded in 1617 by Spanish priest Joseph Calasanz. It is the oldest religious order dedicated to education, and the main occupation of the Piarist fathers is teaching children and youth, the primary goal being to provide free education for poor children. The Piarist practice was to become a model for numerous later Catholic societies devoted to teaching, while some state-supported public school systems in Europe also followed their example. The Piarists have had a considerable success in the education of physically or mentally disabled persons. Some notable individuals taught at Piarist schools include Pope Pius IX, Goya, Schubert, Gregor Mendel, Tadeusz Kościuszko and Victor Hugo. History Joseph Calasanz Joseph Cala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Plasma
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid (all body fluid outside cells). It is mostly water (up to 95% by volume), and contains important dissolved proteins (6–8%; e.g., serum albumins, globulins, and fibrinogen), glucose, clotting factors, electrolytes (, , , , , etc.), hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders. Blood plasma is separated from the blood by spinning a vessel of fresh blood containing an anticoagulant in a centrifuge until the blood cells fall to the bottom of the tube. The bloo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventricle (heart)
A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium (heart), atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles (for example the interventricular septum), while intraventricular means within one ventricle (for example an intraventricular block). In a four-chambered heart, such as that in humans, there are two ventricles that operate in a double circulatory system: the right ventricle pumps blood into the pulmonary circulation to the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta. Structure Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrioventricular Node
The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of the interatrial septum near the opening of the coronary sinus, and conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact (~1 x 3 x 5 mm).Full Size Picture triangle of-Koch.jpg Retrieved on 2008-12-22 Structure Location The AV node lies at the lower back section of the interatrial septum nea ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purkinje Fibre
The Purkinje fibers (; often incorrectly ; 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. Purkinje fibers allow the heart's conduction system to create synchronized contractions of its ventricles, and are essential for maintaining a consistent heart rhythm. Histology Purkinje fibers are a unique cardiac end-organ. Further histologic examination reveals that these fibers are split in ventricles walls. The electrical origin of atrial Purkinje fibers arrives from the sinoatrial node. Given no aberrant channels, the Purkinje fibers are distinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebellum plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language as well as emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine movement, equilibrium, posture, and motor learning in humans. Anatomically, the human cerebellum has the appearance of a separate structure attached to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrite
Dendrites (from Greek δένδρον ''déndron'', "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimulation is transmitted onto dendrites by upstream neurons (usually via their axons) via synapses which are located at various points throughout the dendritic tree. Dendrites play a critical role in integrating these synaptic inputs and in determining the extent to which action potentials are produced by the neuron. Dendritic arborization, also known as dendritic branching, is a multi-step biological process by which neurons form new dendritic trees and branches to create new synapses. The morphology of dendrites such as branch density and grouping patterns are highly correlated to the function of the neuron. Malformation of dendrites is also tightly correlated to impaired nervous sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuron
A neuron, neurone, or nerve cell is an membrane potential#Cell excitability, electrically excitable cell (biology), cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all Animalia, animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to Stimulus (physiology), stimuli such as touch, sound, or light that affect the cells of the Sense, sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to gland, glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Geranium Photopic Mesopic Scotopic
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondary color (made from magenta and yellow) in the CMYK color model, and is the complementary color of cyan. Reds range from the brilliant yellow-tinged scarlet and vermillion to bluish-red crimson, and vary in shade from the pale red pink to the dark red burgundy. Red pigment made from ochre was one of the first colors used in prehistoric art. The Ancient Egyptians and Mayans colored their faces red in ceremonies; Roman generals had their bodies colored red to celebrate victories. It was also an important color in China, where it was used to color early pottery and later the gates and walls of palaces. In the Renaissance, the brilliant red costumes for the nobility and wealthy were dyed with kermes and cochineal. The 19th century brought the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
