The default for the esophagus mucosa is non-keratinized stratified squamous, the submucosa is default, the muscularis is upper ⅓ skeletal, middle ⅓ skeletal and smooth, the lower ⅓ smooth, then adventitia. The stomach mucosa is addition of gastric pits and glands, submucosa is default, muscularis is inner- oblique middle-circular outer- longitudinal smooth muscle, then serosa. The small intestine is mucosa villi with microvilli circular folds, submucosa is default, muscularis is default, duodenum is adventitia, jejunum and ileum are serosa. Large intestine mucosa is intestinal glands, submucosa is default, muscularis is longitudinal=tenia coli creates haustra, cecum, transverse/sigmoid colon=serosa ascending/descending colon, rectum=adventitia. Absorbs water and ions (Na+ and Cl-), forms and stores feces. The ileocecal valves, cecum, ascending colon, right colic flexure, transverse colon, left colic flexure, descending colon, sigmoid colon, rectum, anal canal, and anus. Lacks intestinal villi, teniae coli make haustra, gastrocolic reflex. Filter and remove waste products from blood, 3 processes, filtrate fluids, reabsorption of fluids, ions, nutrients, back into blood from filtrate, secretion of additional waste products from the blood to filtrate. Stores and excretes urine, regulates blood/water volume, ions, acid/base balance, secretes EPO for RBC formation. Organs are 2 kidneys, 2 ureters, urinary bladder, urethra. Kidneys are retroperitoneal, the right kidney is more inferior due to liver, the hilum is where renal vasculature, nerves, and ureters exit. Composed of renal cortex, renal medulla, renal columns, renal pyramids, renal papillae, minor calyx, major calyx, renal pelvis, renal sinus filled with adipose.