Urinary System Lecture 10 PDF

 Urinary system Kidney  Shape: bean-shaped. wy  Site: On both sides of the vertebral column below the ribs.  Structure...

 Urinary system Kidney  Shape: bean-shaped. wy  Site: On both sides of the vertebral column below the ribs.  Structure:  Each kidney contains about one million nephrons. da  Nephron is the anatomical & functional unit of kidney.  Each nephron is formed of glomerulus & tubules.  Tubule is differentiated into proximal convoluted tubule, loop of Henle, en distal convoluted tubule & collecting duct.  Collecting ducts collect together forming minor calyces, which collect H forming major calyces, which finally collect to form renal pelvis.  Functions: R. 1. Remove waste products from blood. 2. Produce erythropoietin which stimulates bone marrow to produce RBCs. 3. Maintain fluid and electrolyte balance of blood D. DR/Hendawy “Anatomist” Page 1  Ureter 25 cm Fibro-muscular tubes that carry urine from kidneys to urinary bladder Urinary bladder wy  Definition: it is a hollow muscular organ which stores urine.  Site: lies in the pelvic cavity behind symphysis pubis.  Shape: Pyramidal in shape having:  Apex (directed anteriorly) da  Base (directed posteriorly) The inner surface of the base is trigone which receives openings of ureters.  Neck “inferior angle” of urinary bladder is surrounded by involuntary sphincter (internal urethral sphincter) to prevent leakage of urine. en Urethra  Beginning: at the neck of urinary bladder  Length: H  Male urethra is 20 cm, divided into: o Prostatic “1.5 inch” o Membranous “0.5 inch” R. o Penile “6 inches” parts  Female urethra is 4 cm.  Termination:  In males: tip of the glans penis. D  In females: vestibule in front of the vaginal orifice.  Surrounded by: external urethral sphincter (voluntary). DR/Hendawy “Anatomist” Page 2  wy da en H R. D DR/Hendawy “Anatomist” Page 3