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The function of the kidneys are as follows: Every day, the kidneys filter gallons of fluid from the bloodstream.
The kidneys then process this filtrate, allowing wastes and excess ions to leave the body in urine while returning needed substances to the blood in just the right proportions. Although the lungs and the skin also play roles in excretion, the kidneys bear the major responsibility for eliminating nitrogenous wastes, toxins, and drugs from the body.
By producing the enzyme renin, they help regulate blood pressureand their hormone erythropoietin stimulates red blood cell production in the bone marrow. Kidney cells also convert vitamin D to its active form. Anatomy of the Urinary System The urinary system consists of two kidneys, two ureters, a urinary bladder, Kidney and smooth muscle a urethra.
The kidneys alone perform the functions just described and manufacture urine in the process, while the other organs of the urinary system provide temporary storage reservoirs for urine or serve as transportation channels to carry it from one body region to another.
The Kidneys The kidneys, which maintain the purity and constancy of our internal fluids, are perfect examples of homeostatic organs. These small, dark red organs with a kidney-bean shape lie against the dorsal body wall in a retroperitoneal position beneath the parietal peritoneum in the superior lumbar region; they extend from the T12 to the L3 vertebra, thus they receive protection from the lower part of the rib cage.
Because it is crowded by the liverthe right kidney is positioned slightly lower than the left. An adult kidney is about 12 cm 5 inches long, 6 cm 2. Atop each kidney is an adrenal gland, which is part of the endocrine system is a distinctly separate organ functionally.
A transparent fibrous capsule encloses each kidney and gives a fresh kidney a glistening appearance. A fatty mass, the perirenal fat capsule, surrounds each kidney and acts to cushion it against blows.
The renal fascia, the outermost capsule, anchors the kidney and helps hold it in place against the muscles of the trunk wall. The outer region, which is light in color, is the renal cortex. Deep to the cortex is a darker, reddish-brown area, the renal medulla. The medulla has many basically triangular regions with a striped appearance, the renal, or medullary pyramids; the broader base of each pyramid faces toward the cortex while its tip, the apex, points toward the inner region of the kidney.
The pyramids are separated by extensions of cortex-like tissue, the renal columns. Medial to the hilum is a flat, basinlike cavity, the renal pelvis, which is continuous with the ureter leaving the hilum. Extensions of the pelvis, calyces, form cup-shaped areas that enclose the tips of the pyramid and collect urine, which continuously drains from the tips of the pyramids into the renal pelvis.
The arterial supply of each kidney is the renal artery, which divides into segmental arteries as it approaches the hilum, and each segmental artery gives off several branches called interlobar arteries.
At the cortex-medulla junction, interlobar arteries give off arcuate arteries, which curve over the medullary pyramids. Small cortical radiate arteries then branch off the arcuate arteries and run outward to supply the cortical tissue.
Nephrons Nephrons are the structural and functional units of the kidneys. Each kidney contains over a million tiny structures called nephrons, and they are responsible for forming urine. One of the main structures of a nephron, a glomerulus is a knot of capillaries.
Another one of the main structures in a nephron is the renal tubule. The inner layer of the capsule is made up of highly modified octopus-like cells called podocytes. Podocytes have long branching processes called foot processes that intertwine with one another and cling to the glomerulus.
As the tubule extends from the glomerular capsule, it coils and twists before forming a hairpin loop and then again becomes coiled and twisted before entering a collecting tubule called the collecting duct, which receives urine from many nephrons.Is Swelling Of The Feet A Sign Of Kidney Failure Feet swelling is one typical sign of kidney disease and kidney failure.
Renal disease is the most common cause of swelling in the feet, ankles, legs as well as face, hands, abdomen, etc. An abrupt or rapid decline in renal function as evidenced by a rapid rise in serum creatinine or decrease in urine output.. Creatinine clearance or filtration is dependent on the glomerular filtration rate (GFR).
The driving force for the GFR is the gradient from the glomerulus to the Bowman space. Contractile proteins of smooth muscle type were found in kidney cells by immunological methods.
The reactions of rabbit anti-actin, anti-heavy meromyosin and anti-myosin antisera with rat kidney were investigated by immunoelectron microscopy. This blog is to help those with kidney disease live a normal healthy life, and provide tools that can help reverse kidney disease, lower creatinine levels, and improve kidney function naturally.
Single-unit smooth muscle in the walls of the viscera, called visceral muscle, has a stress-relaxation response that permits muscle to stretch, contract, and relax as the organ expands.
Multiunit smooth muscle cells do not possess gap junctions, and contraction does not spread from one cell to the next. In smooth muscle cell, the channel is centrally involved in setting the sarcolemmal membrane potential, which controls the activity of voltage-dependent Ca 2+ channels, and hence contractility.
In the nephron, the channel is an important regulator of K + handling.