Urinary System

Nota:

• Urinary Sustem

1. Kidneys
   1. 2x large, reddish, bean-shaped organs
   2. located on the posterior abdominal wall
   3. 2 parts encapsulated by a dense irregular connective tissue capsule
      1. Outer Cortex
      2. Medulla
   4. Highly vascularized
   5. medially-located renal hilum
      1. Ureters
         1. Moves urine from the kidneys to the bladder
            1. Mucosa is distensible
               1. transitional epithelium and a fibroelastic lamina propria
               2. Muscularis externa
                  1. undergoes rhythmic peristaltic contractions to move urine down the ureter towards the bladder
                  2. an inner longitudinal layer
                  3. outer circular layer
                  4. consists of smooth muscle in two layers
                     1. The opposite orientation to that found in the GI tract
                  5. Contains transitional epithelium
      2. Blood vessels and ureters enter and exit the kidney
   6. multi-lobular organ
      1. Renal pyramids
         1. functional lobes
         2. triangular sections of the medulla
            1. apex pointing into the center of the kidney
               1. Collects urine @ each apex
                  1. urine flows into minor calyx
                     1. then major calyx
         3. each is separated from its neighbouring renal pyramids by renal columns
         4. uriniferous tubules
            1. Transverse between
            2. functional units of the kidneys
            3. Nephrons
               1. cortical nephrons
               2. juxtamedullary nephrons
            4. Collecting Tubules
               1. drains urine into the renal pelvis and then exits by the ureter
   7. Main Functions
      1. Production of glomerular filtrate from the blood
      2. Modification of the filtrate to produce urine
2. Bladder
3. Production of urine allows the body to maintain various homeostatic functions
   1. regulates plasma volume and blood pressure by regulating urine volume
      1. (plasma volume and urinary volume are inversely related)