Urinary Tract
George W. Casarett in Radiation Histopathology: Volume II, 2019
The blood vasculature of the kidney is abundant, and about one-fifth of the body’s blood passes through the kidneys per min. Interlobar arteries arise as branches of the renal artery, pass between the pyramids of the kidney, and become arcuate arteries at the cortical-medullary junction. The interlobular arteries are branches of arcuate arteries and follow a radial course through the cortex. The interlobular arteries give off branches to the glomeruli (afferent arterioles) which, after breaking up into the glomerular capillary loops, reform as efferent arterioles which supply capillaries surrounding cortical tubules (Figures 1B and 1C). The interlobular arteries also give off some terminal branches to the renal capsule and subjacent cortex, and the efferent glomerular arterioles, in addition to supplying the blood vessels of the nearby cortical tubules, also give off branches (arteriolae rectae) to the medulla from efferent arterioles near the medulla. The tubules of both the cortex and the medulla are surrounded by capillary plexuses arising from the efferent arterioles of the glomeruli. It is probable that the convoluted tubules of each nephron are usually supplied with the blood that has just passed through the glomerulus of that nephron. Renal arterioles tend to be end arterioles, the only supply to the regions served.
Urinary System
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
The renal vascular supply arises from the renal artery, which branches into the interlobar arteries. The interlobar arteries continue as arcuate arteries that run parallel to the capsule along the corticomedullary junction. These continue as interlobular arteries and eventually to afferent arterioles and glomerular capillaries. Efferent arterioles that arise from glomeruli near the medulla give rise to interconnecting vasa recta which supply the medulla. These vessels eventually coalesce to form arcuate veins. The distal straight (S3) segment of the proximal tubule and focal areas of the medullary thick ascending limb of the loop of Henle are the most susceptible regions of the nephron to ischemic injury (Venkatachalam et al. 1978), but this has more to do with the metabolic oxygen demand and Na+ K+ ATPase activity of these tissues than their architectural arrangement or vascular supply. Cortical short loop nephrons show more extensive damage with ischemia than the long-looped juxtamedullary nephrons. While the cortex receives the vast majority of RBF (>90%) as compared to medulla (resulting in higher vascular concentrations of drug), the medullary ducts are potentially exposed to higher concentrations of drug or metabolites in the urinary solute over time. The major lymphatic drainage follows the vasculature in all species, but an additional capsular lymphatic system has been described in humans and monkeys (Osathanondh et al. 1966).
Urinary system
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha in Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
The kidneys are supplied with blood by the right and left renal arteries, which arise from the lateral aspect of the aorta at around the level of the first lumbar vertebra, just below the origin of the superior mesenteric artery (Fig. 7.13b). Each kidney is usually supplied by a single main artery (Fig. 7.13c) but, not uncommonly, additional segmental arteries may arise directly from the aorta to supply parts of the kidney. The main renal artery divides into two or three lobar arteries, which further divide into segmental arteries, then interlobar arteries, with further divisions into the arcuate and interlobular arteries. The interlobular vessels feed into the afferent arterioles, which supply the glomeruli. After filtration, the blood leaves the glomeruli via efferent arterioles, which drain, in a similar distribution pattern to the afferent arterioles, into interlobular, arcuate and interlobar veins, through to the segmental and lobar veins, which finally drain into the main renal vein that carries blood to the inferior vena cava (IVC). The left renal vein normally passes over the anterior aspect of the aorta to enter the IVC. The left renal vein can sometimes pass behind the aorta to drain into the IVC.
A 9.5-year-old boy with recurrent neurological manifestations and severe hypertension, treated initially for polyarteritis nodosa, was subsequently diagnosed with adenosine deaminase type 2 deficiency (DADA2) which responded to anti-TNF-α
Published in Paediatrics and International Child Health, 2020
Sezgin Sahin, Amra Adrovic, Kenan Barut, Selen Baran, Eda Tahir Turanli, Nur Canpolat, Osman Kizilkilic, Ozan Ozkaya, Ozgur Kasapcopur
Investigations. Haemoglobin was 9.8 g/dL, haematocrit 31.6%, MCV 59.6 fl, platelets 230 × 109/L, leucocytes 10.7 × 109/L [neutrophils 58%, polymorphonuclear leucocytes (PNL) lymphocytes, 31.0% and monocytes 10.0%]. Erythrocyte sedimentation rate (ESR) was 94 mm/h (<20) and C-reactive protein (CRP) 234 mg/L (<10). Owing to widespread myalgia, muscle enzymes were estimated but were within normal limits, as were analyses of electrolytes, liver and renal function and D-dimer levels. Screening tests for thrombophilia did not yield any tendency to thrombosis. Components of cell-mediated immunity and serum IgA (178 mg/dL), IgM (131 mg/dL) and IgE (20 mg/dL) were within normal limits. However, serum IgG was 1933 mg/dL (reference range for Turkish children aged 9 is 646–1620 [17]. Electromyography and nerve conduction studies of lower limbs demonstrated asymmetrical axonal polyneuropathy. There was no response to visual evoked potential and electroretinogram tests of the right eye. While brain MRI findings were compatible with hypertensive encephalopathy in the left prefrontal cortex, electroencephalography was normal. Conventional cranial and visceral angiography was performed to elucidate the malignant hypertension and neurological findings. Angiography of brain was normal. However, visceral angiography demonstrated irregularities and stenosis in some of the branches of the inferior mesenteric artery and renal interlobar arteries bilaterally (Figures 1 and 2).
Effect of inflammation on cytochrome P450-mediated arachidonic acid metabolism and the consequences on cardiac hypertrophy
Published in Drug Metabolism Reviews, 2023
Mohammed A. W. ElKhatib, Fadumo Ahmed Isse, Ayman O. S. El-Kadi
Regarding 18-HETE, it was found almost entirely in the neutral lipid part of the renal cortex (Carroll et al. 1997). It is intriguing to know that a direct association is established between increased 18-HETE levels and insulin resistance in the microvasculature. Also, it has been revealed that elevated levels of 18-HETE are correlated with aberrated vascular recruitment in the skeletal muscles. Subsequently, 18-HETE may be involved in insulin resistance (Chadderdon et al. 2016). In spontaneously hypertensive rats, enhanced phenylephrine vasoconstriction in the renal interlobar arteries has been ascribed to vasoregulatory response due to reduced vascular CYP2E1-generated 18(R)-HETE (Zhang F et al. 2005). This calls for further studies illuminating the roles of 17-HETE and 18-HETE in health and diseases, especially CVDs.
Renal echography for predicting acute kidney injury in critically ill patients: a prospective observational study
Published in Renal Failure, 2020
Hai Jun Zhi, Yong Li, Bo Wang, Xiao Ya Cui, Meng Zhang, Zhen Jie Hu
Renal echography was performed with CX30 and HD15 (both from Philips Healthcare, Bothell, WA, USA) within the first 6 h of admission and after achieving a mean arterial pressure (MAP) of ≥65 mmHg with fluid therapy or vasoactive drugs, by an intensivist with about 3 years of experience in ultrasound operations and with a training certificate from the Chinese Critical Ultrasound Study Group. RRI and Semiquantitative PDU were measured as described in our previous study [19]. Briefly, renal RI was measured from on the interlobar arteries and calculated using the following formula: (peak systolic velocity—end-diastolic velocity)/peak systolic velocity. Three measurements were taken and the mean value was recorded for further analysis. Semiquantitative PDU was conducted using the best blood flow image of energy Doppler ultrasound. Renal perfusion was assessed using semiquantitative PDU scores (Table 2) [22]. During the renal ultrasound examination, MAP, heart rate (HR), type and dose of catecholamine infusion, and oxygenation index were recorded.
Related Knowledge Centers
- Renal Artery
- Renal Circulation
- Renal Lobe
- Arcuate Arteries of The Kidney