![]() ![]() Transport mechanism Active and passive transport mechanisms Calcium must be in a soluble and ionized form before it can be absorbedĪbsorption increased by: Body need Vitamin D Protein Lactose Acid medium Absorption decreased by: Vitamin D deficiency Calcium-phosphorus imbalance Oxalic acid Phosphorous Dietary fiber Excessive fat High alkalinity Also stresses and lack of exercise Excretion increased by: Low parathyroid hormone (PTH) High extracellular fluid volume High blood pressure Low plasma phosphate Metabolic alkalosis Excretion decreased by: - High parathyroid hormone Low extracellular fluid volume Low blood pressure High plasma phosphate Metabolic acidosis Vitamin D3 Absorption and excretion factors.10 % (100 mg/day) of the ingested calcium is excreted in the urine.90 % (900 mg/day) of the daily intake is excreted in the feces.250 mg/day enters intestine via secreted gastrointestinal juices and sloughed mucosal cells.Calcium remaining in the intestine is excreted in the feces.About 35 % is absorbed (350 mg/day) by the intestines.Iron: calcium might have inhibitory effect on iron absorption.Dietary constituents: Phytic acid can reduce absorption of calcium by forming an insoluble salt (calcium phytate).Sodium: ↑ sodium intake, ↑ loss of calcium in urine.Caffeine: ↑ urinary and fecal excretion of calcium. ![]() Phosphate: ↓ calcium excretion in the urine.As component in the blood clotting cascade An active role:as an intracellular signal - In the relaxation and constriction of blood vessels.Found on the outer surfaces of the bones and in the bone cavitiesĬalcium functions Plays important regulatory roles in the body A passive role:.Osteoblasts (bone forming cells) synthesize new bone to replace the resorbed bone.Osteoclasts (bone cells) remodel the bone by dissolving or resorbing bone.Membrane rigidity, permeability and viscosity are partly dependent on local calcium concentrations.Key component in the maintenance of the cell structure.Major structural element in the vertebrate skeleton (bones and teeth) in the form of calcium phosphate (Ca10(PO4)6(OH)2 known as hydroxyapatatite.Bone mineral content (BMC) and bone mineral density (BMD) are used as indicators of calcium insufficiency and as predictors of increased risk of fracture, when compared to a reference range, adjusted for age and gender.Neutron activation analysis enables total body calcium to be measured in living persons.Calcium sensor (GFP-based) fluorescent protein “cameleon” is non invasive and can be targeted to various cellular compartments – enabling a study of spatial and organellar aspects of calcium homeostasis.Fluorescent dyes can be used to measure Ca2+ in vivo.Atomic absorption spectrometry (AAS) can measure total amount of Ca2+ in tissue.99 %) in the skeleton (Bones can serve as large reservoirs, releasing calcium when extracellular fluid concentration decreases and storing excess calcium) Occurs mostly in soil systems as limestone (CaCO3), gypsum (CaSO4*2H2O) & fluorite (CaF2) In the body.In 1883 demonstrated Sydney Ringer the biological significance of calcium - Frog hearts needed the presence of calcium in the bathing solution in order to continue beating.Electrolyzed a mixture of lime & mercuric acid.Isolated in 1808 by Englishman Sir Humphrey Davy.Known as early as first century when ancient Romans prepared lime as calcium oxide.Fifth most abundant element in Earth´s crust.Imaging at 8 and 16 μm reveals a curved plume structure 3 kpc in extent, embedded within the core of the galaxy and coincident with the termination of a 30 kpc long H I tail. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar ''Green Valley'' elliptical galaxy NGC 3226. These findings suggest that even low-level AGNs may be able to launch massive outflows in their host galaxies. The radio continuum energetics implied by the compact VLBA source, as well as archival VLA continuum observations at lower spatial resolution, further support the possibility that the AGN in NGC 1266 could be driving the molecular outflow. The total molecular gas mass is M K that is most consistent with an AGN origin. We present Atacama Large Millimeter/Submillimeter Array CO (1-0) and CO (3-2) observations of SDSS J135646.10+102609.0, an obscured quasar and ultra-luminous infrared galaxy with two merging nuclei and a known 20 kpc scale ionized outflow. ![]()
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