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Renal Autoregulation
Autoregulation is a process within many biological systems, resulting from an internal adaptive mechanism that works to adjust (or mitigate) that system's response to stimuli. While most systems of the body show some degree of autoregulation, it is most clearly observed in the kidney, the heart, and the brain. Perfusion of these organs is essential for life, and through autoregulation the body can divert blood (and thus, oxygen) where it is most needed. Cerebral autoregulation More so than most other organs, the brain is very sensitive to increased or decreased blood flow, and several mechanisms (metabolic, myogenic, and neurogenic) are involved in maintaining an appropriate cerebral blood pressure. Brain blood flow autoregulation is abolished in several disease states such as traumatic brain injury, stroke, brain tumors, or persistent abnormally high levels. Homeometrics and heterometric autoregulation of the heart Homeometric autoregulation, in the context of the circulator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubuloglomerular Feedback
In the physiology of the kidney, tubuloglomerular feedback (TGF) is a feedback system inside the kidneys. Within each nephron, information from the renal tubules (a downstream area of the tubular fluid) is signaled to the glomerulus (an upstream area). Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signaling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level. Background The kidney maintains the electrolyte concentrations, osmolality, and acid-base balance of blood plasma within the narrow limits that are compatible with effective cellular function; and the kidney participates in blood pressure regulation and in the maintenance of steady whole-organism water volume Fluid flow through the nephron must be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homeostasis
In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physics, physical, and chemistry, chemical conditions maintained by organism, living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life. Homeostasis is brought about by a natural resistance to change when already in the optimal conditions, and equilibrium is maintained by many regulatory mechanisms: it is thought to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riboswitch
In molecular biology, a riboswitch is a regulatory segment of a messenger RNA molecule that binds a small molecule, resulting in a change in production of the proteins encoded by the mRNA. Thus, an mRNA that contains a riboswitch is directly involved in regulating its own activity, in response to the concentrations of its effector molecule. The discovery that modern organisms use RNA to bind small molecules, and discriminate against closely related analogs, expanded the known natural capabilities of RNA beyond its ability to code for proteins, catalyze reactions, or to bind other RNA or protein macromolecules. The original definition of the term "riboswitch" specified that they directly sense small-molecule metabolite concentrations. Although this definition remains in common use, some biologists have used a broader definition that includes other cis-regulatory RNAs. However, this article will discuss only metabolite-binding riboswitches. Most known riboswitches occur in b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoregulation Of AraC Expression
Autoregulation is a process within many biological systems, resulting from an internal adaptive mechanism that works to adjust (or mitigate) that system's response to stimuli. While most systems of the body show some degree of autoregulation, it is most clearly observed in the kidney, the heart, and the brain. Perfusion of these organs is essential for life, and through autoregulation the body can divert blood (and thus, oxygen) where it is most needed. Cerebral autoregulation More so than most other organs, the brain is very sensitive to increased or decreased blood flow, and several mechanisms (metabolic, myogenic, and neurogenic) are involved in maintaining an appropriate cerebral blood pressure. Brain blood flow autoregulation is abolished in several disease states such as traumatic brain injury, stroke, brain tumors, or persistent abnormally high levels. Homeometrics and heterometric autoregulation of the heart Homeometric autoregulation, in the context of the circulator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiotensin II
Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. An oligopeptide, angiotensin is a hormone and a dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. Angiotensin was isolated in the late 1930s (first named 'angiotonin' or 'hypertensin') and subsequently characterized and synthesized by groups at the Cleveland Clinic and Ciba laboratories. Precursor and types Angiotensinogen Angiotensinogen is an α-2-globulin synthesized in the liver and is a precursor for angiotensin, but has also been indicated as having many other roles not related to angiotensin peptides. It is a member of the serpin family of proteins, leading to another name: Serpin A8, although it is not know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
