The Urinary System

Components of Urinary System 2 Kidneys (major organs) 2 Ureters (Passage tubes ?) Bladder (Storage) Urethra (excretion)

The Kidney (Shape & Location) Bean shaped organ Location: Post. Abdominal wall, retroperitoneal (?) At vertebral level of ??-?? Protected by 11 th & 12 th ribs Rt. Kidney is slightly lower than lf. (why?)

External Anatomy of Kidney Convex lat. border Concave medial border, Contains in its middle the renal hilum Renal Hilum: The area where str. Enter or leave the kidney (root of the kidney)

Structures within The Hilum From ant. to post.: Renal Vein: most ant. Lf. is longer than Rt. Renal Artery Ureter: most posterior

Internal Anatomy of The Kidney In longitudinal section Outer layer = cortex (divided into 2 zones ?) Inner renal pyramids = medulla (~8-18) Renal columns:?? The kidney is protected by D.Ir.C.T. capsule = Renal Capsule

Draining System Within Kidney Each pyramid contains many collecting ducts  Gathered to form the renal papilla (Apex of the pyramid)  Minor Calyx (Calyx = cup)

Draining System Within Kidney Each pyramid drains into Minor calyx (how many?) Minor calyces join into Major calyx (~2-3) Major calyces join into Renal pelvis Renal pelvis drains to ureter

Arterial Blood Supply To The Kidney Renal a.  Segmental a. (5 a.)  Interlobar a. pass through ??  Arcuate a. over the bases of the pyramids Arching between??  Interlobular Between lobules of the kidney

“The Nephron” The functional unit of the kidney that is responsible for bld. filtration & urine production Each kidney contains ~1 million nephrons (constant #) Consists of: 1. Renal corpuscle 2. Renal tubules

Renal Corpuscle Corpuscle = tiny body Located in ?? Fx.: bld. filtration & urine formation Composed of: 1. Glomerulus: Capillary network 2. Glomerular (Bowman’s) capsule Double walled cup (simple sq. epith.) One side: surround the capillaries (Visceral) Other side: continues with tubules (parietal)

Renal Corpuscle ? ? ? ?

Renal Tubules PCT Cortex Simple cub. epith. Loop of Henle Cortex & Medulla Simple sq. epth. 2 limbs: ? DCT Cortex Simple cub. epith. Drain into ?? Convoluted: tightly coiled

Collecting & Papillary Ducts Collecting Ducts: Larger tubules that receive the DCT of several nephrons * Each collecting duct & group of nephrons draining into it  Renal Lobule Papillary ducts: (see previous slide) Large ducts that result from union of collecting ducts Located at the apex of renal pyramids (renal papilla) Several hundreds in # Drain into ??

Review: 1. Nephron: fxnal unit Renal corpuscle - ? Renal tubules - ? 2. Collecting ducts cortex & medulla 3. Papillary ducts: renal papilla

Renal Transplant Transfer of a kidney from a living donor or cadaver to a pt. with renal failure 1- Donor kidney usually placed in the pt. pelvis 2- Renal a. & v. : attached to iliac a. & v. 3- Ureter: attached to bladder 4- Diseased kidneys: left in place 5- Pt. receives immunosuppressive drugs for life (why?)

Hemodialysis An artificial method for bld. Filtration when kidneys are in renal failure Dialysis Solution Selective permeable membrane CAP Dialysis ? Artificial kidney machine

Ureter Narrow muscular tube that transports urine from the ?? to the ?? (  25 cm) Transportation Mechanisms: 1. Peristaltic contractions: smooth m. on the wall 1 - 5/min 2. Gravity Opens obliquely into the post. Aspect of the bladder (Physiological sphincter)

Ureter 3 areas of constriction: When renal pelvis joins the ureter Over pelvic brim When enters the bladder (posteriorly)

Urinary Bladder Hallow distensible muscular organ located in the pelvis, post. To pubic symphysis Shape: varies (depending on urine content) empty: collapsed normal fill: spherical overfilled: pear-shaped Average capacity ~ ml (  females ??)

Internal Anatomy Rugae & Trigone Rugae: folds of bladder mucosa - more prominent when bladder is ?? Trigone: small triang. Area in the floor of the bladder - No rugae (smooth) - Very sensitive to expansion - Post. Corners= openings of ?, ant. Corner: opening of ?

Urethra Small tube that responsible for urine excretion from the bladder Male: longer (~20cm) 3 parts: Prostatic, membranous & penile Female: Shorter (~4cm)