practice new content Flashcards
what does it mean that the kidneys are retroperitoneal?
the kidneys are located behind the peritoneum, which is the lining of the abdominal cavity
where are kidneys located
in the middle of the back, just below the rib cage, and on either side of the spine
what are the general functions of the urinary system
filter waste products from the blood,
producing urine to eliminate excess water, salts, toxins, and other unwanted substances from the body,
while also regulating the balance of fluids and electrolytes within the body
the main structural and functional unit of the kidney is
a nephron
A renal corpuscle is made of what?
a glomerulus
a network of tiny blood capillaries
and Bowman’s capsule
List in order, from renal corpuscle to collecting duct, the parts of the nephron:
renal corpuscle
proximal convoluted tubule
loop of Henle
distal convoluted tubule
and collecting duct
What are some differences between a cortical and a juxtamedullary nephron?
the length of their loop of Henle
cortical is shorter
juxamedullary is longer
What are some differences between peritubular capillaries and the vasa recta?
Peritubular capillaries are small blood vessels located in the renal cortex, surrounding the proximal and distal convoluted tubules of the nephron
vasa recta are specialized, long, straight capillaries found deep within the renal medulla, running parallel to the loop of Henle, and their main function is to maintain the concentration gradient in the medulla by countercurrent exchange
List the 3 overall steps of urine formation
glomerular filtration, reabsorption, and secretion
what occurs in glomerular filtration
blood is filtered in the kidneys to remove excess fluid and waste products, which are then sent to the urine collecting tubules
what occurs in reabsorption
water and solutes are moved from the renal tubule back into the bloodstream
what occurs in secretion
waste ions and hydrogen ions pass from the capillaries into the renal tubule
What is the glomerular capsule made of (macroscopically)?
a double-layered epithelial structure with an outer parietal layer made of simple squamous epithelium
inner visceral layer consisting of specialized cells called podocytes
Describe the glomerulus and glomerular capsule
Every nephron has a glomerulus, which is a group of tiny blood vessels and the starting point for filtering waste products out of your blood. Bowman’s capsule is a two-walled pouch that covers the glomerulus.
Which blood vessel enters the glomerulus?
afferent arteriole
What are podocytes and what do they have to do with the glomerular capsule?
specialized epithelial cells that form the bowmans capsule
play a crucial role in the filtration process by acting as a barrier that prevents large molecules like proteins from leaking into the urine
Describe the structure of the filtration membrane. What kinds of substances can cross the
filtration membrane?
composed of three layers
water electrolytes and glucose can pass though the membrane
What are the general events that occur in the different regions of the renal tubule and collecting
duct?
the primary event: reabsorption of essential nutrients and water from the filtrate
proximal convoluted tubule: bulk reabsorption
loop of Henle: concentrates the urine
the distal convoluted: tubule fine-tunes electrolyte balance
collecting duct: regulates water
What is hemodialysis used for?
to treat advanced kidney failure, also known as end-stage renal disease (ESRD)
What is lithotripsy used for?
breaks up kidney stones and other stones in the urinary tract, bile ducts, or pancreatic duct