Chapter 26: Urinary System

Metabolic Activities

Processes by which cells consume nutrients and oxygen.

Waste Products

Substances like carbon dioxide and urea produced by metabolism.

Toxic Accumulation

Harmful buildup of wastes in body cells.

Respiratory System

Eliminates carbon dioxide from the body.

Urinary System

Disposes of most metabolic waste products.

Urine Formation

Process of filtering blood and excreting wastes.

Kidneys

Organs that filter blood and produce urine.

Ureters

Tubes transporting urine from kidneys to bladder.

Urinary Bladder

Storage organ for urine until excretion.

Urethra

Tube through which urine exits the body.

Nephrology

Study of kidney anatomy, physiology, and pathology.

Urology

Branch of medicine dealing with urinary systems.

Urologist

Physician specializing in urinary and male reproductive systems.

Excretion of Wastes

Kidneys remove wastes by forming urine.

Nitrogenous Wastes

Waste products containing nitrogen, like urea and uric acid.

Blood Ionic Composition

Regulation of ions like sodium and potassium by kidneys.

Blood pH Regulation

Kidneys adjust hydrogen and bicarbonate ions in blood.

Blood Volume Regulation

Kidneys control water retention to manage blood volume.

Blood Pressure Regulation

Renin secretion by kidneys influences blood pressure.

Blood Osmolarity Maintenance

Kidneys regulate water and solute loss to stabilize osmolarity.

Calcitriol

Active vitamin D form regulating calcium levels.

Erythropoietin

Hormone stimulating red blood cell production.

Gluconeogenesis

Synthesis of glucose from amino acids in kidneys.

Osmolarity

Measure of dissolved particles per liter of solution.

Osmolarity

Total dissolved particles per liter of solution.

Osmolality

Particles of solute per kilogram of water.

Molarity

Concentration of a solution in moles per liter.

Retroperitoneal

Located behind the peritoneum in the abdomen.

Kidney Shape

Reddish, kidney bean-shaped organs.

Kidney Size

Typically 10-12 cm long, 5-7 cm wide.

Kidney Mass

Average mass of 135-150 grams.

Hilum

Indentation where ureter and vessels exit kidney.

Fibrous Capsule

Smooth connective tissue layer protecting the kidney.

Perirenal Fat Capsule

Fatty tissue layer surrounding the fibrous capsule.

Renal Fascia

Connective tissue anchoring kidney to surrounding structures.

Renal Cortex

Outer region of the kidney, light red area.

Renal Medulla

Inner region of the kidney, darker reddish-brown.

Renal Pyramids

Cone-shaped structures in the renal medulla.

Renal Papilla

Apex of renal pyramid pointing toward hilum.

Renal Columns

Cortex extensions between renal pyramids.

Parenchyma

Functional portion of the kidney, includes cortex and pyramids.

Nephrons

Microscopic structures, about 1 million per kidney.

Filtrate

Filtered fluid formed by nephrons.

Papillary Ducts

Ducts draining filtrate from nephrons to calyces.

Minor Calyces

Cups collecting urine from renal papillae.

Major Calyces

Larger cups collecting urine from minor calyces.

Blood Flow Path

Pathway of blood through the kidneys.

Aminor calyx

Receives filtrate from renal papillae.

Major calyx

Collects urine from minor calyces.

Renal pelvis

Large cavity draining urine to ureter.

Urothelium

Epithelium in calyces blocking exchanges.

Renal sinus

Cavity containing renal pelvis and calyces.

Adipose tissue

Stabilizes kidney structures in renal sinus.

Renal blood flow

About 1200 mL/min in adults.

Renal arteries

Supply 20-25% of cardiac output.

Segmental arteries

Branch from renal artery to supply kidney segments.

Interlobar arteries

Run between renal lobes in columns.

Arcuate arteries

Arch between renal medulla and cortex.

Cortical radiate arteries

Radiate into renal cortex from arcuate arteries.

Afferent glomerular arterioles

Supply blood to each nephron's glomerulus.

Glomerulus

Capillary network for blood filtration.

Efferent glomerular arterioles

Carry blood away from glomerulus.

Peritubular capillaries

Surround nephron tubules in renal cortex.

Vasa recta

Straight capillaries supplying renal medulla.

Cortical radiate veins

Drain blood from peritubular capillaries.

Arcuate veins

Collect blood from interlobar veins.

Renal vein

Carries blood to inferior vena cava.

Renal nerves

Regulate blood flow via vasomotor control.

Nephron

Functional unit of the kidney.

Renal corpuscle

Site of blood plasma filtration.

Renal tubule

Regulates filtered fluid post-filtration.

Nephron

Functional unit of the kidney for urine formation.

Renal Corpuscle

Site where blood plasma is filtered.

Glomerulus

Capillary network within the renal corpuscle.

Bowman's Capsule

Double-walled capsule surrounding glomerulus.

Glomerular Filtrate

Filtered fluid from blood plasma.

Renal Tubule

Pathway for filtered fluid after glomerular capsule.

Proximal Convoluted Tubule (PCT)

First section of renal tubule, attached to glomerulus.

Nephron Loop

Connects PCT and DCT, includes descending and ascending limbs.

Distal Convoluted Tubule (DCT)

Final section of renal tubule, further regulates filtrate.

Collecting Duct (CD)

Collects urine from multiple nephrons.

Papillary Ducts

Drain urine into minor calyces.

Cortical Nephrons

80-85% of nephrons, short loops in cortex.

Juxtamedullary Nephrons

15-20% of nephrons, long loops extend into medulla.

Peritubular Capillaries

Blood supply for cortical nephrons.

Vasa Recta

Blood supply for juxtamedullary nephrons.

Ascending Limb

Part of nephron loop returning to cortex.

Descending Limb

Part of nephron loop extending into medulla.

Podocytes

Modified cells forming visceral layer of glomerular capsule.

Pedicels

Footlike projections of podocytes wrapping around capillaries.

Visceral Layer

Inner layer of glomerular capsule with podocytes.

Parietal Layer

Outer layer of glomerular capsule, simple squamous epithelium.

Renal Cortex

Outer region of the kidney housing renal corpuscles.

Renal Medulla

Inner region of the kidney containing nephron loops.

Glomerular Capsule

Double-layered structure surrounding the glomerulus.

Capsular Space

Space between glomerular capsule layers.

Proximal Convoluted Tubule

First segment of renal tubule, reabsorbs nutrients.

Microvilli

Increase surface area for absorption in renal tubule.

Nephron Loop

Part of nephron with descending and ascending limbs.

Thin Ascending Limb

Segment of nephron loop with simple squamous epithelium.