Kidney Tutorial Disscussion

Q) Why is right kidney blood supply longer? ●​ Position on the Aorta and IVC ○​ abdominal aorta = slightly to the left of midline ●​ Inferior vena cava (IVC) ○​ right side of the midline ●​ The route to aorta to kidney is not symmetrical ○​ left kidney ■​ renal artery goes straight on sideway fashion ○​ Right kidney ■​ renal artery must cross midline - in diagonal fashion ■​ posterior on IVC to reach hilum Crossing will make right renal artery longer Q2) Is this opposite for the veins? YES Positon of IVC ●​ IVC lies to right of midline ●​ Aorta lies to left = blood of both kidney must drain toward right to IVC Vein Course Relative lenght Key Relations Right Renal Vein straight from right kideny to IVC on Same side ~2.5 cm Anterior to right renal Artery Left Renal Vein crosses midline, running anterior of aorta ~7.5 cm left gonadal, left supraenal veins prior for entering IVC Q3) Is there surgical affects in different hight between two kidneys? ●​ Liver ○​ right lobe of liver covers majority of right upper quadrants ○​ extends inferiorly to the 10th rib ○​ therefore, right kidney is displaced inferiorly in regards of left kidney ●​ right kidney is placed below costal margin ○​ related to liver duodenum(2nd) and right colic flexure ●​ left remain protected by 11th and 12th rib ○​ reaction to spleen, stomach, pancrease Therefore, they have different surgical exposures ●​ Right Kidney surgical approaches ○​ lies lower = more accessible ○​ subcostal incision is commonly used for exposure of kidney during surguy ■​ just below costal margin ○​ still need to be careful ■​ liver and duodenum overlaps anterior ■​ IVC lies medially in right kidney ●​ could have risk of having injury while approaching hilum ●​ Left Kidney surgical approaches ○​ lies higher, needs incision above 11th and 12th intercostal space ○​ pleural injury is possible if the incision site it too hight ○​ Aortal is placed in medial to hilum ■​ must be cautious for vascular control during surgery ○​ Therefore, intercostal approach is needed Q4) How does RBF autoregulation possible even with Systemic Blood pressure changes? ●​ Renal autoregulations ○​ Ability on kidney to maintain constant renal blood flow ○​ constant GFR even with fluctuation in systemic arterial pressures ○​ within 80-180mmHg ●​ Afferent arteriole contains smooth muscles that will contract once stretched ○​ triggered by increased Blood Pressure ○​ relax when pressure drops 1.​ Increase in systemic blood pressure => increase in glomerular capillary pressure => stretch of afferent arteriole wall 2.​ stretch activated Ca2+ (channel open) => smooth muscle contraction => vasoconstriction 3.​ increase in resistance => restoration of blood flow and GFR returns to normal 4.​ decrease in blood pressure will trigger reverse of process ●​ Autoregulation range ○​ Effective range : Mean arterial pressure of 80-180mmHg ○​ Below 80mmHg : flow falls => renal ischemia ○​ Above 180 mmHg : protection fails => glomerular injury, hypertensive nephrosclerosis Condition NSAID use Mechanism Affected Blocks prostaglandins → ↓ vasodilation Consequence Can ↓ RBF → acute kidney injury ACE inhibitors / ARBs Inhibit Ang II → ↓ efferent constriction Drop in GFR in renal artery stenosis Severe hypotension (<80 mm Hg) Autoregulation fails Acute tubular necrosis High BP (>180 mm Hg) Myogenic & TGF overwhelmed Glomerular capillary rupture, nephrosclerosis