Lecture 24 Urinary System

Urinary System Anatomy Anterior Kidney Stomach Pancreas Large intestine Ureter Liver Abdominal aorta Renal vein Inferior vena cava Renal artery Right kidney Renal hilum Fibrous capsule Spleen Fat Urinary bladder Rib Left kidney Fig. 27.2 Urethra Posterior (a) Anterior view Fig. 27.1 External Anatomy of Kidneys Renal capsule surrounds each kidney Hilum renal artery and nerves enter and renal vein and ureter exit kidneys

Internal Anatomy of Kidneys Renal cortex: Outer area Renal columns Renal medulla: Inner area Renal pyramids Calyces Major: Converge to form renal pelvis Minor: Collects urine from individual renal pyramid Nephron: Functional unit of kidney Fig. 27.3

The Nephron Renal corpuscle Arterioles Tubules Collecting ducts Bowman’s capsule Glomerulus network of capillaries Arterioles Afferent blood to glomerulus Efferent drains Tubules Proximal (convoluted) tubule Loops of Henle Descending limb Ascending limb Distal (convoluted) tubule Collecting ducts Fig. 27.5

Ureters and Urinary Bladder tubes through which urine flows from kidneys to urinary bladder Urinary bladder stores urine Urethra transports urine from bladder to outside of body difference in length between males and females sphincters Internal urinary External urinary Ureter Peritoneum Ureteral openings Neck of urinary bladder Internal urethral sphincter External urethral sphincter Fig. 27.9

Review Question Think back for a moment to the lectures on histology. What type of epithelium would line the inside of the ureters and urinary bladder? Stratified squamous Pseudostratified columnar Simple cuboidal Transitional Simple squamous

Points to Remember Kidney filters blood to eliminate metabolic wastes (e.g. urea formed from ammonia that is removed from blood by liver) and reabsorb substances such as sugars, amino acids, sodium and chloride Functional unit of kidney is nephron Ureters, urinary bladder and urethra transport urine (product of nephron) outside of body

Questions?