Urinary System Flashcards
Angiotensinogen is synthesizes by the liver, but must be activated to angiotensin I by ____.
renin
In the presence of what hormone can the collecting tubules become permeable to water?
vasopressin (ADH)
Are the collecting tubules part of countercurrent exchange?
YES
What surrounds the muscle layers of the ureters?
fibroelastic adventitia of connective tissue
The ____ is responsible for active resorption of Na and Cl, coupled with the secretion of H and K ions.
distal convoluted tubule
What is infection in the bladder called?
cystitis
Do podocytes have phagocytic capabilities?
YES
The renal ____ and ____ are lined by specialized epithelial tissue called transitional epithelium, or urothelium.
calyces; pelvis
Which portion of the male urethra is lined with transitional epithelium, like the bladder?
prostatic
_____ nephrons are located in the outer rim of the cortex and have short loops of Henle.
Cortical/subscapular
What is the most common protein excreted in the urine?
albumin
Where is the resultant ultrafiltrate of the glomerulus passed into?
renal tubule
What is the functional unit of the kidney?
nephron
What are the 3 components of the juxtaglomerular apparatus (JGA)?
- macula densa
- juxtaglomerular cells
- extraglomerular mesangial cells
The ____ of the kidney contains mostly loops of Henle, collecting tubules, and collecting ducts.
medulla
ADH ____ gives rise to hypertonic urine; ADH ____ gives rise to hypotonic urine.
sufficiency; insufficiency
What is the infection called if a bladder infection spreads up to the renal pelvis?
pyelonephritis
What are the 4 distinct zones of the renal tubule?
- proximal convoluted tubule
- loop of Henle
- distal convoluted tubule
- collecting tubule/duct
ACE-inhibitors act to ____ blood pressure by preventing the conversion of what hormone to its most potent form?
decrease; angiotensin I
A decrease in blood pressure also causes a decrease in _____, which results in a drop in Na+ concentration.
glomerular filtration rate (GFR)
When ____ is released from the zona glomerulosa of the adrenal cortex, the resorption of Na+ and water from the distal convoluted tubule increases blood pressure.
aldosterone
What does the countercurrent multiplier system result in?
the production of hypertonic urine (concentrated)
When juxtoglomerular cells detect a decrease in blood pressure, they release renin from the _____ arteriole.
afferent
The ____ of the kidney contains mostly renal corpuscles and convoluted tubules.
cortex
How many layers of muscle does the bladder contain?
3 (interspersed with elastic fibers)
What is the space called that sits between the capillary basement membrane and second layer of podocytes?
subpodocyte space
What mineralocortocoid controls the distal convoluted tubule?
aldosterone
A ____ is a network of densely-packed anastomosing, fenestrated capillaries.
glomerulus
Why is BUN not really a great determinant of present renal function?
levels cannot really be detected until 75% of nephrons have been lost
What glands located in the urethra secrete mucus and lie within the pseudostratified columnar epithelium?
paraurethral glands
Where do medullary rays converge?
renal papillae, when they empty into minor calyces
What is the principle organ responsible for water and electrolyte homeostasis, osmoregulation, and acid-base balance?
urinary system
What results from a decreased glomerular filtration rate?
decreased concentration of Na+ in the distal convoluted tubule
What are the 3 major types of nephrons?
- cortical/subscapular
- juxtamedullary
- intermediate
_____ are integral proteins that form specialized pores or channels for transport of water in the brush border of epithelial cells.
Aquaporins
Is there a brush border present in proximal convoluted tubules?
YES -characteristic of proximal convoluted tubules
Why is there specialized transitional epithelium called urothelium in the kidney?
it is highly distensible and allows for changing urine volumes
The ____ is the terminal portion of a nephron; several tubules converge to form a larger ____.
collecting tubule; collecting duct
Vitamin D is converted from the inactive to the active form by the ____ and ____.
liver; kidney
What component of the JGA is a chemoreceptor sensitive to changes in Na+ concentration in the filtrate?
macula densa
_____ nephrons are adjacent to the medulla and have long loops of Henle.
Juxtamedullary
Kidneys synthesize renin and maintain normal blood pressure via which system?
the renin-angiotensin-aldosterone system
In the nephron, a ____ is a single layer of squamous epithelial cells resting on a basement membrane (the parietal layer).
capsule
What is the secondary site of urine concentration in humans?
collecting tubules
What layer of the glomerulus acts as a physical barrier and ion-selective filter?
glomerular basement membrane
_____ facilitates the activity of special aquaporins that allow permeability of water in the collecting tubules.
Vasopressin (ADH)
What component of the JGA are modified smooth muscle cells in the wall of the afferent arteriole?
juxtaglomerular cells
Angiotensin I must be converted into angiotensin II by ____.
ACE (angiotensin converting enzyme)
What actions move urine down to the bladder?
peristaltic contractions
Can urinary stones be broken apart by ultrasound?
YES - lithotripsy
Filtration slits contain slit diaphragms made up of the protein _____.
nephrin
What is the space between the visceral and parietal layers called that collects glomerular filtrate and empties into the renal tubule?
Bowman’s space
The scalloped outline of transitional epithelium are referred to as ____ cells.
umbrella
What is ACE made by?
endothelial cells in lungs
What does the first layer of the glomerulus consist of?
capillary endothelial cells
glomerular basement membrane
The ____ is embryologically derived from the nephrogenic blastema, part of the developing ____.
nephron; urogenital ridge
What are some complications of urinary stones?
hydronephrosis
hydroureter
Macromolecules larger than what molecular weight would be unable to pass through slit diaphragms?
molecules with a MW larger than 69 kD
_____ nephrons are located in the middle of the cortex and have intermediate length loops of Henle.
Intermediate
Which organs are involved in handling decreased blood pressure?
- liver (angiotensinogen)
- kidney (renin)
- lungs (ACE)
- adrenal glands (aldosterone)
Does the urinary system metabolize and excrete antibiotics when present in the body?
YES
ADH secretion from the ____ increases water resorption from the collecting tubules and increases blood pressure.
posterior pituitary
What 2 cell types control the distal convoluted tubule?
principle cells
intercalated cells
The ____ forms the hollow, dilated end of a proximal convoluted tubule that surrounds the glomerulus.
capsule
Increased frequency of urination is called ____.
polyuria
What are the cells of the visceral layer of a renal corpuscle capsule called?
podocytes
What is the purpose of the layers of muscle in the ureters?
to move urine via peristaltic contractions
Is the luminal surface of the capillary endothelium negatively or positively charged?
negatively
Your patient complains of constant thirst and frequent urination. What hormone are they most likely deficient in?
ADH
The ____ detects pressure changes and ion concentration.
juxtaglomerular apparatus
What would a patient be diagnosed with if they excrete proteins in their urine?
proteinuria
What is the parietal layer of a capsule that continues into the glomerulus called?
turns into the visceral layer
Why is podocalyxin important in the glomerulus?
its negatively-charged barrier prevents loss of anions and large protein molecules
Where would you find lacis cells?
at the pole of the glomerulus, above the macula densa
What does the urinary system excrete? What are the two principle waste products?
toxic and metabolic waste products; urea and creatinine
Afferent arterioles lead to what structure of the kidney?
glomeruli
Why are BOTH efferent and afferent vessels arterioles in the glomerulus?
high hydrostatic pressures, so stronger vessels prevent leaking
What is the primary soluble nitrogenous waste product in mammals?
urea
Why is the luminal surface of the capillary endothelium negatively charged?
the surface layer of glycoprotein podocalyxin sets up a negatively charged barrier
Why is the urinary bladder lined by urothelium and contains a fibroelastic lamina propria?
to allow for distention
What is the peritoneal or visceral surface of the bladder covered by?
fibroblastic adventitia (serosa)
The thin limbs of the loop of Henle are ____ in juxtamedullary nephrons and ____ in cortical nephrons.
long; short
The kidney is divided into an outer ____ and inner ____.
cortex; medulla
What do kidneys synthesize that maintains normal blood pressure through the renin-angiotensin-aldosterone system?
renin
Does the distal convoluted tubule contain a brush border?
NO - but does have short apical microvilli
Describe the arterial blood flow into the kidney.
renal artery»_space; interlobar arteries»_space; arcuate arteries»_space; interlobar arteries»_space; afferent arterioles
Does the renal tubule concentrate waste products?
YES - urea, creatinine, excess H+ and K+
A ____ test measures renal function and is an indirect measure of renal disease.
BUN
____ is the formation of crystals or stones (urinary calculi) in the urinary tract.
Nephrolithiasis (pelvis) OR Urolithiasis (bladder)
What are the 4 parts to a loop of Henle?
- pars recta (thick descending limb)
- thin descending limb
- thin ascending limb
- thick ascending limb
____ is the term for when functional nephrons have been lost (about 75%).
uremia
What type of epithelium lines the lumen of the ureters?
transitional epithelium (thrown into folds)
Are kidneys retroperitoneal or mesenteric organs?
retroperitoneal (with fibrous connective tissue capsule)
___ surround the glomerular capillaries.
Podocytes
Where is urine temporarily stored before being sent to the ureters?
renal pelvis
Higher extracellular Na+ in the medulla, combined with water resorption by the proximal convoluted tubule creates a ______.
cortico-medullary interstitial gradient
Which distinct zone of the renal tubule is responsible for 75% of water and ion (Na, Cl) resorption?
proximal convoluted tubule
____ arteries are present in the cortex of the kidney.
Interlobar
What are the two components to a renal corpuscle?
Bowman’s capsule
glomerulus
From what zone of the adrenal cortex is aldosterone released from in the renin-angiotensin-aldosterone system?
zona glomerulosa
____ of the distal convoluted tubule resorb K and secrete H.
Intercalated cells
What is the peritubular capillary network called that surrounds the loop of Henle?
vasa recta
Which regions of the nephron contain microvilli?
proximal convoluted tubule
pars recta
distal convoluted tubule (short)
In the cortex, the extracellular fluid is more _____; in the medulla, the extracellular fluid is more _____.
dilute; concentrated (salty)
The process of water and ion resorption in the proximal convoluted tubule is facilitated by what structures?
aquaporins
Urea and creatinine are nitrogen-containing compounds from the metabolism of _____.
proteins
What component of the JGA are flattened cells with cytoplasmic processes that surround the afferent and efferent arterioles?
extraglomerular mesangial cells
What surrounds the urethral opening in the bladder?
internal sphincter
What are the passage determinants through slit diaphragms?
molecular size, charge, and shape
Increased frequency of drinking (chronic thirst) is called ____.
polydypsia
The cortico-medullary interstitial gradient produces the ____ of urine concentration.
countercurrent (exchange) multiplier system
Does the pars recta have a brush border of apical microvilli?
YES - like the proximal tubule
What is the classic cause of PUPD?
diabetes insipidus
What openings define the trigone area of the urinary bladder?
2 for entry of urine via ureters; 1 for urethral opening
What is the rate of filtrate production in the renal tubule in humans?
120 mL/min
What are the primary functions of the renal tubule?
- selective resorption of water
- resorption of inorganic ions (Na+ and bicarbonate)
- resorption of large molecules (amino acids, proteins, glucose)
- from the glomerular filtrate
_____ function in Na resorption, maintenance of acid-base balance, K secretion and K resorption in the renal pyramids.
Collecting tubules
How much of the 120 mL of filtrate is actually converted into urine in the renal tubule?
only about 1 mL
What structures do primary foot processes give off?
secondary foot processes known as pedicels
Where is sodium pumped to in the areas surrounding the loop of Henle?
into the extracellular interstitia of medulla
Is the glomerulus supplies by afferent or efferent arterioles?
BOTH
Vitamin D is very important in ____ metabolism.
calcium
What are the two major components of a nephron?
renal corpuscle
renal tubule
What do ACE-inhibitors do?
prevent an increase in blood pressure by preventing conversion of angiotensin I to angiotensin II by blocking the action of ACE
Where are proximal convoluted tubules confined to?
the cortex of the kidney
Do collecting tubules contain both principle and intercalated cells?
YES
Goormaghtigh cells or Lacis cells are ____ cells.
extraglomerular mesangial
In the glomerulus, blood passes through several cell layers to become filtrate, and then this is filtered into ____.
Bowman’s space
Which product of the renin-angiotensin-aldosterone system is the most potent vasoconstrictor that can raise blood pressure?
angiotensin II
The distal convoluted tubule is present within the ____ of the kidney.
cortex
The ____ of the loop of Henle are long in juxtamedullary nephrons and short in cortical nephrons.
thin limbs
What specialized structure is used to regulate systemic blood pressure via the renin-angiotensin-aldosterone system?
juxtaglomerular apparatus
The _____ is a combined baroreceptor and chemoreceptor in the nephron.
juxtaglomerular apparatus
What does erythropoietin stimulate?
red blood cell production (via erythropoiesis)
What component of the JGA is a thickened region of columnar epithelial cells on one side of the distal convoluted tubule?
macula densa
What activates angiotensin I?
renin (by activating angiotensinogen)
What act as an additional barrier on the glomerulus to restrict passage of large molecules, proteins, and blood cells?
slit diaphragms
Podocytes surround the glomerular capillaries and possess cytoplasmic extensions known as ____.
foot processes
80% of urinary calculi are made up of _____.
calcium oxalate
What specialized cells in the JGA produce renin in response to low blood pressure?
juxtaglomerular cells
What is the more technical term for urination?
micturition
Where are the collecting tubules visible? What are they called?
in the renal pyramids; medullary rays
What does BUN measure?
blood urea nitrogen (BUN) measures the amount of urea, creatinine, uric acid, and ammonia present in the urine
The ____ of a nephron filters blood plasma; the ____ collects filtrate.
renal corpuscle; renal tubule
Where does the renal tubule start?
Bowman’s capsule (surrounds it)
How is the high osmotic pressure accomplished in the loop of Henle?
through Na-K pumps in the thick ascending limb
_____ resorb water, ions, proteins, amino acids, and sugars.
Proximal convoluted tubules
What would a patient be diagnosed with if they excrete glucose in their urine?
glucosuria (diabetes mellitus)
____ cells in the JGA convert angiotensinogen to angiotensin I by producing renin.
juxtaglomerular cells
At what region of the kidney do blood vessels and ureters enter and exit?
hilus
Your patient presents with bladder cancer. What anatomical region in the bladder most likely houses the tumor? Why?
trigone area; this hill-like area almost always has remaining urine stuck to it, which may lead to neoplasticity
The ___ consists of specialized areas of afferent arterioles and the distal convoluted tubule.
juxtaglomerular apparatus
____ of the distal convoluted tubule resorb Na and water and secrete K.
Principle cells
Diabetes insipidus is due to ____ insufficiency, which leads to high volume, dilute hypotonic urine.
ADH
What is ADH secreted by?
posterior pituitary
What are the 3 sections of a male urethra?
prostatic
membranous
spongy (penile)
Where does the bulk of the loop of Henle extend into?
the medulla
What component of the JGA act as baroreceptors and detect changes in blood pressure?
juxtaglomerular cells
How many layers of smooth muscle does the muscularis externa of the ureter contain?
3
- inner longitudinal
- outer circular
- outermost longitudinal
What are the spaces between foot processes called?
filtration slits
Is urea soluble? Is uric acid soluble?
YES; NO
PUPD is the clinical abbreviation for increased ____ and _____.
urination; thirst
What are the 3 ways in which angiotensin II acts to raise blood pressure?
- vasoconstriction
- release of aldosterone
- ADH secretion
What are the differences in epithelium in the thin and thick limbs of the loop of Henle?
thin - simple squamous
thick - simple cuboidal
Are epithelial cells of the collecting duct permeable or impermeable to water?
impermeable
_____ cells of the JGA are thought to provide structural support and phagocytosis and may assist in tubular glomerular feedback.
Extraglomerular mesangial
How long is the renal tubule in humans?
55 mm long
Where is erythropoietin produced?
in the kidneys
Where would you find the outermost longitudinal muscle layer in the ureter?
in the lower third of the ureter
What is the function of the loop of Henle?
to generate high osmotic pressure in the extracellular fluid of the renal medulla
