Urinary System Chapter 25
How many nephons are in each kidney?
1 million
What are the three layers of JG apparatus
1. fenestrated glomerular endothelium 2. visceral layer of bowman's capsule 3. fused basement membrane
What percent of blood flow goes to the kidneys?
20%
What is max compacity of the bladder
600ml, 250ml is the urge to void
Which of the following is the best explanation for why the cells of the proximal convoluted tubule (PCT) contain so many mitochondria?
A great deal of active transport takes place in the PCT.
What is the order of blood flow for the kidneys?
Aorta, Renal, Segmental, Interlobar, Arcuate, Cortical Radiate (ARS IAC) Microscopic: Afferent arteriole, Glomerulus capillaries, Efferent Arterioles
Which of the following statements best describes the difference between the intrinsic and extrinsic controls of the kidney?
Extrinsic controls have the greatest effect on systemic blood pressure while intrinsic controls have a greater effect on GFR.
True/False Filtrate becomes less concentrated as it flows down the medullary collecting ducts, toward the renal pelvis.
False
True/False: Blood pressure in the renal glomerulus is lower than in most parts of the body in order to conserve body water.
False
If efferent arterioles vasodilate what will happen to the GFR, Urine output, and Net filtration pressure?
GFR: decrease Urine Output: decrease Net Filtration Pressure: decrease
What are intrinsic vs extrinsic controls of the bladder?
Intrinsic: autoregulation, tubuloglomerular feedback Extrinsic: hormonal and neural controls key stimulus is a drop on BP
What is the function of the distal convoluted tubule
K+ secretion
Urine Formation Pathway
Pyramid papilla, Minor calyx, Major calyx, Renal pelvis, Ureter
If the diameter of the efferent arterioles leading away from the glomerulus increases (vasodilation), which of the following is NOT likely to occur?
Systemic blood pressure will decrease.
True/False The position of the kidneys behind the peritoneal lining of the abdominal cavity is described by the term retroperitoneal.
True
True/False: In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water.
True
True/False: Under normal conditions, the proximal convoluted tubule (PCT) reabsorbs nearly all of the glucose, lactate, and amino acids in the filtrate and 65% of the Na+ and water.
True
If the diameter of the afferent arterioles leading to the glomerulus decreases (vasoconstriction), what will happen to the urine output, net filtration pressure, GFR, and systemic BP
Urine Output: decreases Net Filtration Pressure: decreases GFR: decreases Systemic BP: increases
function of macula densa cells
act as chemoreceptors that monitor concentration
The thin segment of the nephron loop's descending limb ________.
aids in the passive movement of H2O out of the capsule, this is because the NaCl concentration is much higher here, thus water will follow the solute
What hormone promotes active tubular secretion of potassium ions and reabsorption of sodium ions in the distal convoluted tubule (DCT) and collecting ducts?
aldosterone
The ________ artery lies on the boundary between the cortex and medulla of the kidney.
arcuate
Reabsorption of sodium in the medulla by active transport is undertaken by cells that compose which of the following?
ascending nephron loop
The kidneys are stimulated to produce renin ________.
by a decrease in BP
The __________ collect(s) urine, which drains continuously from the papillae, and empty it into the __________.
calyces; renal pelvis
What is the effect of antidiuretic hormone on the cells of the collecting duct?
causes aquaporins to be inserted into the apical membranes
The descending limb of the nephron loop ________.
contains fluid that becomes more concentrated as it moves down into the medulla
True/False: Capsular hydrostatic pressure is the chief force pushing water and solutes out of the blood and across the filtration membrane.
false: it is globular
What fails to pass through the visceral layer of bowman's capsule?
fats and proteins
What is the function of the glomerulus
filtration of the plasma
What are the steps of urine formation
glomerular filtration, tubular secretion, tubular reabsorption
Which capillary bed produces filtrate?
glomerulus
Your patient's urinalysis shows a large amount of protein in the urine. This suggests a problem in the ____________
glomerulus
What two structures constitute the renal corpuscle?
glomerulus and glomerular (Bowman's) capsule
What is the chief force pushing water and solutes out of the blood and across the filtration membrane of the glomerulus?
hydrostatic pressure pushing out from the globmerular capillaries
Suppose that a patient has a failing liver and is unable to make normal levels of albumin for the blood plasma. If all other factors remain the same, what would be the effect on the amount of filtrate produced?
increase
Alcohol acts as a diuretic because it ________.
inhibits the release of ADH
When renal calculi obstruct a ureter, pain is perceived to radiate from the lower back to the anterior abdominal wall on the same side. This is an event that ______.
is called referred pain
The glomerulus differs from other capillaries in the body in that it ________.
it is drained by an efferent arteriole
What are the two types of nephons?
juxtamedullary and cortical
Reabsorption of nutrients like glucose and amino acids takes place in the proximal convoluted tubule (PCT) via cotransporters that utilize secondary active transport. Which of the following would stop the reabsorption of glucose at the apical surface of the cells in the PCT?
loss of Na+-K+ ATPase in the basolateral surface of PCT cells
What are the function of the kidneys?
metabolism vitamin D to its active form regulate blood volume and osmolality maintain acid-base balance Carry out gluconeogenesis during prolonged fasting
What is the function of the macula densa cells of the juxtaglomerular complex (JGC)?
monitor the NaCl content of the filtrate
Why is the afferent arteriole larger than the efferent arteriole?
more bf goes in that comes out, more smooth muscle because of pre-capillary sphincter, greater impact on gfr
The functional and structural unit of the kidneys is the ________.
nephron
What would happen if the capsular hydrostatic pressure were increased above normal?
net filtration would decrease
How is urine moved through the ureters?
peristalsis
What area of the nephron is responsible for the reabsorption of most of the water from the filtrate as well as most nutrients?
proximal convoluted tubule
function of juxtaglomerular apparatus
regulate bf and concentration
What is the most direct function of the juxtaglomerular apparatus?
regulate blood pressure and the rate of blood filtration by the kidneys
Which of the following is the primary function of the juxtaglomerular complex?
releases chemical signals that regulate the rate of filtrate formation
Which of the following is the site where we would find the majority of the nephron loops?
renal pyramids
What are glomerular filtration rate control methods
renal, hormonal, and neural
histology of proximal and distal convoluted tubule
simple cuboidal
histology of collecting ducts
simple cuboidal epithelium
histology of glomerular capsule
simple squamous (parietal) fenestrated endothelial (visceral)
histology of loop of henle
simple squamous (thin-segmented cells)
function of JG cells (juxtaglomerular)
smooth muscle in afferent arterioles, vasoconstriction
The fatty tissue surrounding the kidneys is important because it ________.
stabilizes the position of the kidneys by holding them in their normal position
What defines the trigone of the urinary bladder?
the opening to the urethra
The urinary bladder is composed of ________ epithelium.
transitional
What is micturition
urination
What is the micturition reflex
urination reflex, active stretching of the transitional epithelium controls this
The function of angiotensin II is to ________.
vasoconstrict and raise BP
What is the function of the proximal convoluted tubule
water reabsorption
