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apparatus[ap″ah-rat´tus] (pl. appara´tus, apparatuses)
One abnormality of the QRS complex is increased voltage resulting from enlargement of heart muscle, which produces increased quantities of electric current. A low-voltage QRS complex may result from toxic conditions of the heart, most commonly from fluid in the pericardium. Pleural effusion and emphysema also can cause a decrease in the voltage of the QRS complex.
Gol·gi ap·pa·ra·tus(gol'jē ap'ă-rat'ŭs)
Golgi apparatusA collection of stacked, flattened, cup-shaped sacs situated in the CYTOPLASM of cells near the nucleus and concerned with the movement of materials within the cell. The Golgi apparatus receives protein-containing vesicles from the endoplasmic reticulum, glycosylates them, sorts them into groups for different locations and transports them to other parts of the cell or to the cell membrane for export. (Camillo Golgi, 1843–1926, Italian microscopic anatomist).
dictyosomea series of cell ORGANELLES consisting of a stack of membrane-lined vesicles called CISTERNAE, first described by Camillo Golgi in 1898 but only clearly defined from studies with the ELECTRON MICROSCOPE. See Fig. 178 . The membranes of the Golgi apparatus are produced from vesicles pinched off from the ENDOPLASMIC RETICULUM and secretory vesicles are formed by the apparatus which move to the periphery of the cell and may carry out EXOCYTOSIS. The apparatus is thought to have a storage role as well as enabling the assembly of simple molecules into more complex ones, for example, the packaging of carbohydrates and proteins into glycoprotein.
Golgi,Camillo, Italian histologist and Nobel laureate, 1844-1926.
Golgi apparatusintracellular transport system formed of channels and vesicles facilitating modification, storage and packaging of intracellular products, secretory proteins and lysozomal enzymes prior to their release from the cell (see Table 1)
|Cell membrane||Bimolecular lipid and protein membrane that surrounds the cell|
• Bi-layer of non-polar lipid molecules (phosphatidylcholine, phospharidylethanolamine, cholesterol) that acts as a barrier to water and hydrophilic solutes
|Cell cytoplasm||The gel-like matter contained within the membrane envelop:|
• Contains and supports specialized organelles, including the cell nucleus, endoplasmic reticulum, the Golgi apparatus, mitochondria and lysozomes
• Stores substances (glycogen and lipids)
• Synthesizes and metabolizes essential substances (amino acids, fatty acids, monosaccharides)
• Synthesizes and translates protein
• Contains microtubules which help maintain the form of the cell and form intercommunication channels between organelles
|Cell cytoskeleton||A complex network of structural elements (microtubules, intermediate filaments and microfilaments) which determine the shape of the cell, its ability to move and its response to external stimuli|
|Cell nucleus||Present in all eukaryotic cells capable of mitosis|
Contains the cell genome (DNA) and the means of replication and transcription of RNA
Separated from the cytoplasm by the nuclear envelop (which disappears during mitosis and meiosis)
Contains the nucleolus, where ribosomes are synthesized
|Intercellular connections||There are two types of intercellular connections: tight junctions and gap junctions|
|Cell adhesion molecules (CAMs)||Structures (receptor integrins, immunoglobulin adhesion molecules, Ca+-dependent cadherins and carbohydrate-binding selectins) within the cell membrane that bond to laminins within the extracellular matrix to attach adjacent cells to one another and to the basal membrane|
Gol·gi ap·pa·ra·tus, Golgi body , Golgi complex (gol'jē ap'ă-rat'ŭs, bodē, kompleks)
Golgi apparatus (gōl´jē),
Golgi body or