Urinary System Flashcards

Vocabulary flashcards for reviewing the urinary system.

Kidneys

Organs of the urinary system that receive 25% of cardiac output and produce urine.

Ureters

Tubes that receive urine from the kidneys and conduct it to the urinary bladder via peristalsis.

Urinary Bladder

Organ that receives and stores urine; contraction of its walls drives urination.

Urethra

Tube that conducts urine from the bladder to the outside of the body.

Hilum

Medial indentation on the kidney; point of entry/exit for renal artery, renal nerves, renal vein, and ureter.

Fibrous Capsule

Layer of collagen fibers covering the outer surface of the kidney.

Perinephric Fat

Thick layer of adipose tissue surrounding the kidney; also known as the perinephric fat capsule.

Renal Fascia

Dense, fibrous outer layer that anchors the kidney to surrounding structures.

Renal Cortex

Superficial region of the kidney.

Renal Medulla

Inner region of the kidney; contains renal pyramids.

Renal Pyramid

Conical structure within the renal medulla.

Renal Papilla

Tip of the renal pyramid.

Renal Column

Separates adjacent renal pyramids in the renal medulla.

Kidney Lobe

Consists of a renal pyramid, the overlying cortex, and adjacent renal columns.

Minor Calyx

Collects urine from a single kidney lobe.

Major Calyx

Formed by the fusion of 4–5 minor calyces.

Renal Pelvis

Funnel-shaped structure that collects urine from major calyces and is continuous with the ureter.

Nephron

Functional unit of the kidney responsible for urine formation.

Cortical Nephrons

85% of nephrons, located primarily in the cortex, responsible for most regulatory functions.

Juxtamedullary Nephrons

15% of nephrons, with long nephron loops extending deep into the medulla, essential for producing concentrated urine.

Renal Corpuscle

Part of the nephron where blood pressure forces water and solutes out of glomerular capillaries in filtration.

Renal Tubule

Tubular passageway in the nephron that receives filtrate and modifies it to create urine.

Glomerular Capsule (Bowman’s Capsule)

Cup-shaped chamber surrounding the capillary network of the glomerulus.

Glomerulus

Capillary network within the renal corpuscle where filtration occurs.

Proximal Convoluted Tubule (PCT)

Segment of the nephron that reabsorbs nutrients from the filtrate (tubular fluid).

Nephron Loop

Establishes osmotic gradient for water reabsorption; contains a thin and thick segment in each limb.

Distal Convoluted Tubule (DCT)

Segment of the nephron that adjusts tubular fluid composition by reabsorption and secretion.

Afferent Arteriole

Supplies blood to each individual nephron.

Efferent Arteriole

Carries blood from the glomerulus to the peritubular capillaries.

Peritubular Capillaries

Collect water and solutes absorbed by the nephron and deliver other solutes for secretion; drain into cortical radiate veins.

Vasa Recta

Long, straight capillaries parallel to the nephron loop, transporting water and solutes within the renal medulla.

Urea

Most abundant organic waste; by-product of amino acid breakdown.

Creatinine

By-product of creatine phosphate breakdown in muscles.

Uric Acid

Formed during recycling of nitrogenous bases of RNA.

Rugae

Folds in the bladder lining that disappear with expansion as the bladder fills.

Ureteric Orifices

Slit-like shape helps prevent backflow of urine into ureters with bladder contraction.

Detrusor Muscle

Collectively forms the muscularis layer with inner longitudinal, circular, and outer longitudinal layers.

Polyuria

Excessive urine production.

Oliguria

Reduced urine production (50–500 mL/day).

Anuria

Severely reduced urine production (0–50 mL/day).