BSC2086L E.9 Urinary System

Developed for the Broward College course BSC2086/L Anatomy and Physiology II.

kidney

The organ that filters blood and excretes waste as urine.

renal capsule

The thin outer shell of the kidney.

renal hilum

• The concavity of the kidney.

• Admits the ureters, renal a., renal v., lymphatics, and nerves.

• Also known as the hilus of the kidney.

renal cortex

• The outermost region of the internal kidney.

• Superficial to the renal medulla.

• Appears slightly granular.

renal medulla

• The middlemost region of the internal kidney.

• Deep to the renal cortex and superficial to the renal pelvis.

• Contains triangular renal pyramids.

• Appears striated due to the presence of tubules and ducts.

renal pyramid

• A triangular structure found in the renal medulla.

• The base faces the renal cortex.

• The renal papilla (apex) faces the renal pelvis.

renal papilla

The apex of the renal pyramid facing the renal pelvis.

renal column

An area of granular tissue (similar to the cortex) between renal pyramids.

minor calyx

• A cup-like extension that collect urine from the renal papilla.

• Converges with others to form a larger major calyx.

major calyx

• The convergence of several minor calyces.

• Drains into the renal pelvis.

renal pelvis

• The innermost region of the internal kidney.

• Collects urine from the major calyces and drains it into the ureters.

• Includes the minor and major calyces.

renal artery

• The largest a. of the kidney.

• Supplies the entire kidney.

• Branches into smaller segmental aa.

segmental artery

• Branches of the renal a.

• Branches into smaller interlobar aa.

interlobar artery

• Extends between the renal pyramids.

• Branches of a segmental a.

• Branches into smaller arcuate aa.

arcuate artery

• Extends along the base of the renal pyramids.

• Branches of an interlobar a.

• Branches into smaller interlobular aa.

interlobular artery

• Extends through the renal cortex.

• Branches of an arcuate a.

• Branches into an afferent arteriole of a glomerulus.

interlobular vein

• Extends through the renal cortex.

• Converges into an arcuate v.

arcuate vein

• Extends along the base of the renal pyramids.

• The convergence of interlobular vv.

• Converges into an interlobar v.

interlobar vein

• Extends between the renal pyramids.

• The convergence of arcuate vv.

• Converges into the renal vein.

renal vein

• The largest vein of the kidney.

• Drains blood from the entire kidney.

• The convergence of interlobar vv.

ureter

• A narrow tube channeling urine from the kidneys to the urinary bladder.

• Composed of an outer adventitia, middle muscularis, and inner mucosa.

adventitia

• Slide histology of the ureter.

• The outermost layer of the ureter.

• Composed of connective tissue.

• Superficial to the circular layer of the muscularis.

circular layer of muscularis

• Slide histology of the ureter.

• A smooth muscle layer of the ureter.

• Superficial to the longitudinal layer of the muscularis and deep to the adventitia.

longitudinal layer of muscularis

• Slide histology of the ureter.

• A smooth muscle layer of the ureter.

• Superficial to the mucosa and deep to the circular layer of the muscularis.

mucosa

• Slide histology of the ureter.

• The innermost layer of the ureter.

• Composed of urothelium.

• Faces the lumen of the ureter and is deep to the longitudinal layer of the muscularis.

urinary bladder

The hollow sac organ that collects and temporarily stores urine.

rugae

• Part of the urinary bladder.

• Folds of the mucous membrane of the bladder.

• Flattens as the bladder fills with urine to increase capacity.

trigone

• Part of the urinary bladder.

• The triangle formed by the ureteral openings and internal urethra orifice.

ureteral opening

• Part of the urinary bladder.

• A posterior opening on either side of the of the bladder led in by the ureters.

internal urethral orifice

• Part of the urinary bladder.

• The anterior opening of the bladder leading to the urethra.

detrusor muscle

• Part of the urinary bladder.

• The muscularis of the bladder.

• Contracts to expel urine from the bladder.

mucosa

• Slide histology of the bladder.

• The innermost layer of the bladder.

• Composed of urothelium.

• Faces the lumen of the bladder and is deep to the submucosa.

submucosa

• Slide histology of the bladder.

• A layer of the bladder.

• Superficial to the mucosa and deep to the muscularis.

muscularis

• Slide histology of the bladder.

• A muscular layer of the bladder.

• Also known as the detrusor muscle.

• Superficial to the submucosa.

urethra

A tubular organ carrying urine from the bladder to the exterior during micturition (voiding of urine).

external urethral orifice

• Part of the urethra.

• The opening of the urethra to the exterior.

internal urethral sphincter

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• Part of the urethra.

• A circular layer of circular smooth muscle located just after the internal urethral orifice.

• Involuntary muscle allowing urine to flow outward.

external urethral sphincter

• Part of the urethra.

• A layer of skeletal muscle located just before the external urethral orifice.

• Voluntary muscle allowing urine to flow out to the exterior.

nephron

• The functional subunit of the kidney.

• Site of urine formation and renal function.

• Composed of a renal corpuscle and a renal tubule.

renal corpuscle

• Part of a nephron.

• Filters blood.

• Composed of a glomerulus enclosed within a glomerular capsule.

glomerulus

• Slide histology of the nephron.

• Part of a renal corpuscle.

• The capillary network of a renal corpuscle.

capsular space

• Slide histology of the nephron.

• Part of a renal corpuscle.

• The interior of the glomerular capsule.

glomerular capsule

• Slide histology of the nephron.

• Part of a renal corpuscle.

• A wall enclosing the glomerulus.

• Shown in the image is the parietal layer.

podocyte

• Part of a renal corpuscle.

• A cell with pedicels.

• Wraps around the glomerulus and forms the visceral layer of the glomerular capsule.

pedicel

• Part of a renal corpuscle.

• A foot-like process of a podocyte forming part of the filtration membrane.

macula densa

• Part of a renal corpuscle.

• A group of columnar cells in the DCT that monitors fluid composition and filtration rate.

renal tubule

• Slide histology of the nephron.

• Part of a nephron.

• Modifies glomerular filtrate by reabsorption and secretion of water and ions.

• Divided into the proximal convoluted tubule, loop of Henle, and distal convoluted tubule.

proximal convoluted tubule

• The first part of a renal tubule.

• Primary site of water and solute reabsorption.

• Begins immediately after the renal corpuscle.

• Abbreviated PCT.

descending limb

• The proximal second part of a renal tubule.

• Part of the loop of Henle.

• Permeable to water but not solutes.

ascending limb

• The distal second part of a renal tubule.

• Part of the loop of Henle.

• Permeable to solutes but not water.

distal convoluted tubule

• The third part of a renal tubule.

• Primary site of secretion of excess solutes.

• Abbreviated DCT.

collecting duct

• The convergence of several distal convoluted tubules.

• Descends through the renal pyramid.

• Merges with others to form larger papillary ducts that drain into the minor calyces.

• Abbreviated CD.

afferent arteriole

• Branches of an interlobular artery.

• Supplies the glomerulus of a nephron for blood filtration.

efferent arteriole

Vessel carrying blood away from the glomerulus to the peritubular capillaries.

peritubular capillaries

• Branches of an efferent arteriole.

• Supplies the adjacent renal tubules in the renal cortex.

vasa recta

• Branches of an efferent arteriole.

• Supplies the loops of Henle in the renal medulla.