Urinary System

• Nephron is the basic functional unit of kidney.
• Functions of Nephron include excretion of waste product (nitrogenous excretion is done via renal excretion, which is water soluble, while biliart secretion is done for fat soluble waste products).
• Nephron also regulates water through sodium retention by the juxtaglomerular cell in between afferent and efferent arterioles.
• Parenchymatous organ types include Carnivorous with uni-lobar kidney, Large Ruminant with multilobar kidney, Small Ruminant with uni-lobar kidney, and Pigs with elongated/bean-shaped, multilobar kidney.
• Parts/Organization of Kidney include Cortex, Medulla, and Ureter.
• Cortex of Kidney is divided into Pars convoluta and Pars radiata.
• Pars convoluta of Kidney includes Renal corpuscle and Bowman’s Capsule/Glomerular Capsule.
• Renal corpuscle of Kidney is part of Pars convoluta and is composed of Parietal layer (Simple squamous), Visceral Layers (Glomerular epithelium), and Convoluted tubules.
• Bowman’s Capsule/Glomerular Capsule of Kidney is part of Pars convoluta and is composed of Parietal layer (Simple squamous), Visceral Layers (Glomerular epithelium), and Convoluted tubules.
• Convoluted tubules of Kidney are part of Bowman’s Capsule/Glomerular Capsule and are the longest and widest portion of the nephron.
• Ductus Collecting tubules of Kidney are part of Pars radiata and are simple cuboidal epithelium.
• Pars radiata of Kidney includes Loop of Henle.
• Juxtaglomerular Apparatus consists of Juxtaglomerular cells, Macula Densa, and extraglomerular mesangial cells.
• Substances Secreted by Kidney include Erythropoietin, Calcitirol, Prostaglandins primarily PGE2, and Renin.
• Ureter of Kidney is lined by transitional epithelium and has a high concentration of Zona Occludens which prevents the dilution.