Urinary System Flashcards
What do kidneys produce?
urine via removal of metabolic wastes from circulation
What is the function of the ureters?
transport urine toward the urinary bladder
What is the function of the urinary bladder (muscular sac)?
Temporarily store urine prior to urination.
What is the function of the urethra?
Conducts urine to the exterior; in males, it also transports semen.
What is the primary function of the urinary system?
To remove most metabolic wastes produced by body’s cells
Urination/micturition
contraction of muscular urinary bladder forces urine through urethra and out of body
Three functions of the urinary system?
Excretion: removal of metabolic wastes from body fluids.
Elimination: discharge of wastes from body
Homeostatic regulation: of volume and solute concentration of blood.
How does a kidney receive blood?
through a renal artery.
Flow of blood to and away from the nephron:
Afferent arteriole > glomerulus > efferent arteriole > peritubular capillaries
The fibrous capsule
covers the surface of the kidney.
The perinephric fat
protects the kidney from damage
The renal pyramid helps to
with blood filtration and water concentration regulation within your kidneys
Renal nerves help with
innervating kidneys and ureters
enter each kidney at hilum
follow branches of renal arteries to individual nephrons
Nephrons are
microscopic functional units of kidneys
each consists of renal corpuscle and renal tubule
each renal tubule empties into collecting system
Bowman’s capsule
surrounds the glomerular capillary loops and participates in the filtration of blood from the glomerular capillaries.
Bowman’s capsule also has a structural function and creates a urinary space through which filtrate can enter the nephron and pass to the proximal convoluted tubule.
The function of the filtration slits is
to allow some exchange of materials, or “leaking”, from within the fenestrated capillaries of the glomerulus.
The Renal Tubule has two convoluted tubule
Proximal convoluted tubule (PCT)
Distal convoluted tubule (DCT)
What are the PCT and DCT separated by?
the loop of Henle: U-shaped tube + extends partially into medulla
While traveling along the renal tubule, the tubular fluid gradually changes in composition due to
substances being reabsorbed or secreted in various segments of nephron.
Function of the Juxtaglomerular complex (JGC) helps
regulate blood pressure and filtrate formation
What does the JGC consist of?
Macula dense
Juxtaglomerular cells
Extraglomerular mesangial cells
Macula dense contains
chemo and baro-receptors
Juxtaglomerular cells contains
modified smooth muscle cells
Extraglomerular mesangial cells provide
feedback between cells.
Cortical nephron
mainly perform excretory and regulatory functions
The Juxtamedullary nephron helps to do what with urine?
concentrate and dilute urine
Peritubular capillaries
filter waste from your blood so the waste can leave your body through urine
Vasa recta
bring nutrients and oxygen to the medullary nephron segments but, more importantly, they also remove the water and
solute that is continuously added to the medullary interstitium by these nephron segments.
Specialized capillaries in the kidney
What is the main difference between cortical juxtamedullary nephrons?
Cortical nephrons (85% of all nephrons) mainly perform excretory and regulatory functions, while juxtamedullary nephrons (15% of nephrons) concentrate and dilute urine.
What is the goal of urine production? How is this achieved?
to maintain homeostasis.
By regulating volume and composition of blood + excretion of metabolic wastes.
What are the three main metabolic wastes?
Urea: most abundant organic waste.
Creatinine: breakdown of creatine phosphate.
Uric acid: recycling of nitrogenous bases.