Ebook Physiology question - based learning: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Physiology question - based learning: Part 2
Ebook Physiology question - based learning: Part 2
Part IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2ting urine and its contents as a waste product. The formation of urine is linked to a diverse range of physiological functions. The ability of the kidneys to vary the urine concentration is part and parcel of renal osmoregulation. The excretion of small or large urine volumes is associated with regu Ebook Physiology question - based learning: Part 2lation of water balance in the body. Renal osmoregulation and control of water balance are both linked to the homeostasis of the common parameter of eEbook Physiology question - based learning: Part 2
xtracellular fluid (ECF) sodium concentration.The ECF volume and blood volume are also under the governance of the kidneys. ECF volume is determined bPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2ntrol. The kidneys also secrete an erythropoietic hormone that maintains the normal hematocrit. Maintaining normal total body sodium or sodium balance is a major role of the renal nephrons. The nephrons and its supply of blood vessels are the target of renal sympathetic nen e which acts during sodiu Ebook Physiology question - based learning: Part 2m conservation.It might seem odd. unrelated, and a surprise to think about a sympathetic neural activity being involved in sodium electrolyte balance.Ebook Physiology question - based learning: Part 2
The kidneys are the primary source of the hormone enzyme renin which is the initiator of a family of antinatriuretic hormones including angiotensin IPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2not to forget this, think of BP and BPee.The other important ECF cation that is under renal control is potassium. The renal handling of potassium includes tubular reabsorption and secretion. The adrenal steroid hormone aldosterone has a dual action in regulating the potassium balance besides sodium Ebook Physiology question - based learning: Part 2balance.The blood pH cannot remain at the normal 7.4 if our kidneys malfunction. The renal tubules secrete protons, reabsorb and synthesize bicarbonatEbook Physiology question - based learning: Part 2
e which is quantitatively the major base in the ECF. Think of this essential renal function in acidbase balance as peeH. There is a transmembrane exchPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2 are integrated with cardiovascular physiology in ensuring normal arterial blood pressure. The kidneys w (wee) and the lungs V (ventilation), closely function together in arterial blood pH control. The kidneys and lungs sequentially generate the vasoconstrictor circulating peptide, angiotensin II wh Ebook Physiology question - based learning: Part 2ich besides increasing total peripheral resistance is also a central mediator of euvolemia.Chapter 1JRenal Hemodynamics and GFRThe resting kidneys recEbook Physiology question - based learning: Part 2
eive around 20% of the normal cardiac output. About 90% of this renal blood flow (RBF) enters the nephrons (estimated 1 million kidney) to be filteredPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2lular fluid (ECF) volume is a third at 14 L. Thus, glomerular filtration processed almost 13 times the total ECF and reflects a major role of the kidneys in the homeostasis of the ECF. the “internal aqueous environment" that bathes all cells. Filtration is the first step in urine formation. Urine fl Ebook Physiology question - based learning: Part 2ow rate is about 2 L day. highlighting a large amount of water reabsorption from the glomerular filtrate. The final urine that is excreted is the netEbook Physiology question - based learning: Part 2
output from the three basic renal handling processes for both water and solutes—filtration, reabsorption, and secretion.Changes in RBF produce parallePart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2ion of RBF. The autoregulatory mechanisms of RBF (myogenic and macula densa sensing) are explained hemodynamically by the same “Flow = Pressure Resistance" equation, the resistance altered being the preglomerular afterent arteriole. The glomerulus is a unique capillary in being sandwiched between tw Ebook Physiology question - based learning: Part 2o arterioles—the afterent and the efferent. Downstream from the glomerular capillary network separated by the efferent arteriole is the peritubular caEbook Physiology question - based learning: Part 2
pillary, which participates in tubular reabsorption and secretion (Fig. 11.1).1What two determinants are used to calculate the GFR?Answer The GFR is dPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2endent on two factors, the surface area available for filtration of the plasma water and the water or hydraulic permeability. The student should note that the GFR is not dependent on solute permeability as we are dealing with the movement of fluid volume not filtered solute load. The surface area fo Ebook Physiology question - based learning: Part 2r filtration can be altered by the degree of contraction of the glomerular mesangial cells. Vasoactive agents can reduce the Kf when the mesangial celEbook Physiology question - based learning: Part 2
ls contract.€> Springer International Publishing Switzerland 201599H. M. Cheng. Physiology Question-Based Learning, DOI 10.1007/978-3-319-12790-3 1110Part IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2of the three Starling’s forces across the glomerular capillary; opposing hydrostatic pressures in rhe glomerulus and Bowman’s capsule and (he glomciulai oncotic pressureThe glomerulus is a capillary; and so the Starling’s capillary forces are operative in explaining glomerular filtration. If the stu Ebook Physiology question - based learning: Part 2dents appreciate capillary dynamics, when this topic was covered under cardiovascular physiology, the derivation of the net filtration pressure is a wEbook Physiology question - based learning: Part 2
ee (meaning as easy as our urine flow!)In the glomerular capillary, the two Starling’s forces are the hydrostatic pressure and the plasma oncotic presPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2aks out from the glomerulus. Hence, the oncotic pressure in the Bowman’s space is near to zero mmHg.There arc then three Starlings forces with the glomerular hydrostatic pressure being the only force promoting filtration, lhe net filtration pressure is the arithmetic sum of the three forces.A few un Ebook Physiology question - based learning: Part 2ique characteristic of the glomerular Starling’s forces deserve mention. First, the glomerular hydrostatic pressure (Pgc) is distinctly higher than inEbook Physiology question - based learning: Part 2
other microcirculations. Second, the Pgc only drops slightly along the glomerulus. This relatively constant high hydrostatic pressure is obviously esPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2gc for nitration.I he glomerular oncotic pressure (#gc), on the other hand, increases along the capillary. From about 25 mmHg al the afferent arteriolar end of the glomerulus, the #gc reaches about 40 mmHg “downstream.” Ihis increasing =gc is due to the high filtration ửaclion in the glomerulus, a v Ebook Physiology question - based learning: Part 2alue of 20%, so the plasma protein is progressively more concentrated along the glomerulus, rhe value of the #gc in the GFR equation is therefore notEbook Physiology question - based learning: Part 2
a single value but a mean value.There is no capillary reabsorption at the glomerulus, and the net filtration pressure decreases progressively along thPart IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2renal plasma flow, not RBF as red cells are confined within the glomerulus.2What is the expected effect of sympathetic action of the afferent arteriole on filtration fraction?Answer The filtration fraction will be unchanged.Concept Filtration fraction is the ratio of the GFR to the renal plasma flow Ebook Physiology question - based learning: Part 2. At rest, this has a value of about 0.2. This means that a fifth of the total renal plasma flow is filtered. If the renal sympathetic nerve vasoconstEbook Physiology question - based learning: Part 2
ricts only the preglomerular afterent arteriole (which never happens in vivo, see next question 3), we can think about the effects on RBF and the GFR.Part IIIRenal Physiology98Part III Renal PhysiologyIntroduction: Renal PhysiologyThe kidneys produce urine. Pee Wee! The kidneys are not merely excret Ebook Physiology question - based learning: Part 2. The effect on GFR will be mediated by any effects of sympathetic nerve on the Starling's forces that contribute to the net filtration pressure that produce the GFR. Since the glomerulus is “downstream” from the afferent preglomerular arteriole, the hydrostatic pressure that promotes filtration wil Ebook Physiology question - based learning: Part 2l be reduced. GFR will be decreased.Gọi ngay
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