Chapter 26: The Urinary system Flashcards

Question

What is the Glomerular (Bowman's) Capsule?

Answer 1

a double walled epithelial cut that surrounds the glomerular capillaries, from which blood plasm is filtered at as it passes through. Note: (The Strain where blood passes through)

Answer 2

True: * **Myogenic Mechanism** : occurs when stretching triggers contractions of smooth muscle cells in the wall of the afferent arterioles. * **Tubulogolmerular Feedback** : is so named because part of the renal tubules - *Macula Densa (MD)* - provides feedback to the glomerulus.

Answer 3

the MD are a group of cells crowded together in an area of the ascdending Loop of Henle that makes contact with the afferent arteriole. P. 1075

Answer 4

* When GFR (Glomerular Filtration Rate) is above normal due to elevated systemic blood pressure, filtered fluid flows more rapidly along the renal tubules. ----\> * ----\> As a result, the proximal convoluted tubule and Loop of Henle have less time to reabsorb Na+, Cl- and water. * Macula Densa (MD) cells are thought to detect the increased delivery of Na+, Cl-, and water and to inhibit release of Nitric Oxide (NO) from cells in the juxtaglomerular apparatus (JGA). Because NO causes vasodilation, afferent arterioles constrict when the level of NO declines. * As a result, less blood flows into the glomerular capillaries, and GFR decreases. * When blood pressure falls, causing GFR to be lower than normal, the opposite sequence of events occurs, although to a less degree. Tubuloglomerular Feedback operates more slowly than the Myogenic Mechanism.

Answer 5

True * As Urea accumulates in the interstitial fluid, some of it diffuses into the tubular fluid in the descending and thin ascending limbs of the long loops of Henle, which are also are permeable to urea * However, while the fluid flows through the thick ascending limb, distal convoluted tubule and cortical portion of the collecting duct, urea remains in the lumen because cells in this segment are permeable to it. * As fluid flows along the collecting ducts, water reabsorption continues via osmosis because ADH is present * This waster reabsorption *further increases* the concentration of urea in the tubular fluid, more urea diffuses into the interstitial fluid of the inner renal medulla P. 1092

Answer 6

_False_ **Urinary Incontinace** : a lack of voluntary control over micturation * **Urge Incontinence** is most common in older people and is characterized by an abrupt and intense urge to urinate followed by an involuntary loss of urine. * **Stress Incontinence** is the most common type of incontince in you and middle aged females, and results from weakness of the deep muscles of the pelvic floor. As a resul, any physical stress that increases abdominal pressure, such as coughing, sneezing etc, causes leakage in urine from the urinary bladder.

Answer 7

_True:_ the Principle of Filtration 1. Glomerular capillaries present a large surface area for filtration because they are long and extensive. The mesangial cells regulate how much of this surface area is available for filtration. 2. The Filltration membrane is this and porous. Despite having several layers, the thickness of the filtration membrane is only 0.1mm. 3. Glomerular Capillary BP is high. Because the efferent arteriole is smaller in diameter than the afferent arteriole, resistance to the outflow of blood from the glomerulus is high. P. 1078

Answer 8

_False:_ The afferent arterioles is larger than the efferent arteriole. P. 1078

Answer 9

_False_: * **Liver** : The liver is primary site of _metabolic recycling_, as occurs, for example: _the conversionof amino acids into glucose or of glucose into fatty acids_. The liver also _converts toxic substances into less toxic ones_, such as amonia into urea * **Lungs** : With each exhalation, the lungs _excrete CO², and expel heat and a little water vapor_. P. 1100

Answer 10

_Cortex_ Together, the _renal cortex_ and _renal pyramids_ of the _renal medulla_ constitute the **Parenchyma** P. 1069

Answer 11

_Glomerular Capsule_ * **Nephrons**: consist of two parts: **Renal Corpuscle**, where blood plasma is filtered and a **Renal Tubule** into which the filtered fluid passes. * **Renal Corpuscle**: consist of two components: **Glomerulus**, Caipillary network, and the **_Glomerular (Bowman's) Capsule_**, a double-walled epithelial cup that surrounds the glomerular capillaries. P. 1071

Answer 12

action of Atrial Natriuretic Peptide (ANP) on meangial cells P. 1081

Answer 13

* Narrowing of lumen of the afferent arteriole * increased release of renin * decrease release of nitric oxide by the juxtaglomerular appartus * production of angiotensin II P. 1080-1081