Urinary Flashcards
1. Describe the basic function of the urinary system.
1.Homeostasis. Rid body of liquid waste water balance filter blood vitamin D activation regulates blood pressure and regulates erythropoiesis.
- List the major components of the urinary system.
2.Kidneys Ureters Urinary bladder Urethra
- Define retroperitoneal as it relates to the kidney.
3.External to parietal peritoneum
- List the 3 protective layers of the kidney.
4.Inner to outer: Renal capsule adipose capsule renal fascia
- Describe the following renal structures: Hilus renal cortex renal medulla pyramid renal papillae renal pelvis and renal calyces (calyx).
5.Medial indentation where blood vessels enter/exit kidney cortex is outer portion of kidney medulla is inner medulla has triangular shaped regions called pyramids the apex (point) of each pyramid is a papilla the pelvis is a funnel-like structure inside the kidney in the region of the hilus collecting urine from the pyramids and has extensions into the pyramids called calyces.
- Describe the blood flow to the kidney.
6.Tremendous! Via Renal arteries. About 1/5 of cardiac output
- Name the functional microscopic unit of the kidney and describe its specific parts.
7.Nephron; Glomerulus & Glomerular capsule Renal tubules including proximal convoluted tubule descending limb of the loop of Nephron loop of nephron ascending limb of loop of nephron distal convoluted tubule followed by collecting ducts or tubules.
- Describe the glomerulus and the renal corpuscle.
8.Glomerulus is a tuft or network of permeable blood capillaries. It is surrounded by the capsule (Bowman’s Capsule) and these two structures comprise the renal corpuscle. Renal = Kidney
- Describe the overall nephron physiology. Define urine.
9.Nephrons filter blood to make liquid waste or urine. They control blood pressure volume and pH. They remove waste from bloodstream such as protein metabolic waste called urea.
- Describe glomerular filtration.
10.Filtration occurs from the glomerulus into the glomerular capsule. It is a passive process influenced by the size of the particles & whether or not they can fit through the pores of the glomerulus and not based on need. Blood pressure in the glomerulus certainly is a driving force.
- Describe the factors that favor and oppose glomerular filtration.
11.Glomerular hydrostatic pressure (is blood pressure in glomerulus) drives filtration. Opposing factors are not strong enough to oppose filtration but include the osmotic pressure in the glomerulus as well hydrostatic pressure in the glomerular capsule.
- Discuss the effects of increased blood pressure and decreased blood pressure (as in hemorrhaging) on glomerular filtration.
12.Increased pressure increases filtration and decreased pressure decreases filtration
- Describe active and passive tubular reabsorption and give examples.
13.Active reabsorption requires ATP and passive does not. Glucose is reabsorbed from the proximal convoluted tubule to the bloodstream by active transport. Water follows passively.
- Discuss the significance of an increasingly concentrated interstitial fluid as you descend from the cortex to the medulla. Describe how this concentration is maintained.
14.The significance is that as you descend into the medulla the interstitial fluid is very concentrated which offers some great “drawing” power for pulling water out of the kidney tubules. The concentration is maintained by having the vasa recta operate in a countercurrent mechanism so that all of the solutes are not removed from the interstitial region. Additionally urea adds to the interstitial concentration as does differential permeability of the different portions of the nephron.
- Describe the reabsorption and secretion that occur in all parts of the nephron.
15.The proximal convoluted tubule is where most reabsorption occurs. Most nutrients and water are reabsorbed here. As you descend the limb of the nephron it is permeable to water and water is reabsorbed. At the loop urea enters the loop from the interstitial region & is recycled back into the urine. The ascending limb is permeable to salt but not water. As you ascend into a weakly concentrated interstitial region the salt will be reabsorbed. The distal convoluted tubule is ADH and aldosterone dependent. If ADHis present water is reabsorbed. If aldosterone is present sodium is reabsorbed and water passively follows. The collecting duct is also hormone dependent. If ADH is present you will have significant water reabsorption resulting in small amounts of highly concentrated urine. It gets so concentrated that near the bottom of the collecting duct even urea is reabsorbed into the interstitial region. Secretions of substances such as hydrogen ions ammonia and drugs occur primarily in the convoluted tubules. Here substances can pass directly from the bloodstream into these tubules.
