Mastering A&P II- Chapter 25 Practice Urinary System

The ________ artery lies on the boundary between the cortex and medulla of the kidney.

arcuate

The presence of protein in the urine indicates which of the following?

damage to the filtration membrane

If the GFR is too low, needed substances may pass so quickly through the renal tubules that they are not absorbed and instead are lost in the urine. T/F

False

The path urine takes after it is formed until it leaves the body is the urethra, urinary bladder, and finally the ureter. T/F

False

Which of the following acts as the trigger for the initiation of micturition (voiding)?

Mechanical stretching of the bladder wall

Which of the following is NOT a major urine formation process?

Micturition Micturition is the process of urinating, releasing stored urine after it is formed.

Which of the hormones below is responsible for facultative water reabsorption?

ADH

Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg.

25 mm Hg60 - (25 + 10) = 25 mm Hg Yes, 60 - (25 + 10) = 25 mm Hg. The two pressures that oppose filtration must be subtracted from the force favoring filtration.

Place the following in correct sequence from the formation of a drop of urine to its elimination from the body. 1. major calyx 2. minor calyx 3. nephron 4. urethra 5. ureter 6. collecting duct

3, 6, 2, 1, 5, 4

Which of the choices below is not a function of the urinary system?

Answer: d) Eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat a) Regulates blood glucose levels and produces hormones b) Maintains blood osmolarity c) Helps maintain homeostasis by controlling the composition, volume, and pressure of blood d) Eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat

Which vessels are most intimate with the nephron loop and serve as a point to collect ions and water back into the blood?

Answer: vasa recta The vasa recta are intimate with the nephron loop and serve as a point to collect ions and water back into the blood.

In what part of the renal tubule does parathyroid hormone (PTH) promote the reabsorption of calcium ions?

Distal Convoluted Tubule Parathyroid hormone (PTH) promotes the reabsorption of calcium ions in the distal convoluted tubule (DCT).

Upon reaching what point in the nephron is reabsorption (1) dependent upon the body's needs at the time and (2) regulated by hormones?

Distal convoluted tubule (DCT) reabsorption only occurs under the influence of hormonal regulation.

The longer the nephron loop descends into the medulla, the less concentrated the urine will be. T/F

False The longer the nephron loop descends into the medulla, the more concentrated the urine will be.

The medullary pyramids contain collecting tubules (ducts) that travel towards the renal cortex, carrying urine to exit the kidney. T/F

False The medullary pyramids contain collecting tubules that travel towards the renal papillae, carrying urine to exit the kidney.

A major calyx is a component of which of the following anatomical structures?

Renal pelvis The major branches of the renal pelvis are the major calyces, and the smaller branches that contact the renal papillae are the minor calyces.

Which statement does NOT accurately describe the renal gross anatomy?

The left kidney is lower in position because of crowding by the liver. The right kidney is lower in position because of crowding by the liver.

Which of the following is NOT a characteristic of the cortical nephrons?

Their nephron loop is closely wrapped with vasa recta. Cortical nephrons have a short nephron loop that dips into the medulla but is not wrapped in vasa recta. Absorption of materials from these nephrons happens in the proximal and distal tubules via the peritubular capillaries.

Aldosterone is a hormone that causes the renal tubules to reclaim sodium ions from the filtrate. T/F

True

In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the loop of Henle of the juxtamedullary nephrons (the countercurrent multiplier) and the flow of blood through the limbs of adjacent blood vessels (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically. T/F

True

The nephrons and collecting ducts are the structures responsible for urine formation. T/F

True

The position of the kidneys behind the peritoneal lining of the abdominal cavity is described by the term retroperitoneal. T/F

True

Tubular secretion is effective in controlling blood pH T/F

True

A relatively large afferent arteriole on one side of the glomerulus compared to a relatively smaller efferent arteriole creates an increase in hydrostatic pressure that drives glomerular filtration. t/f

True Not all of the blood from the afferent can drain into the smaller efferent. This backup creates a pressure at the glomerulus called the glomerular hydrostatic pressure that drives filtration.

Under normal conditions, the proximal convoluted tubule (PCT) reabsorbs all of the glucose, lactate, and amino acids in the filtrate and 65% of the Na+ and water.

True The PCT quickly recovers nutrients, leaving the latter parts of the nephron to use the water and salt remaining as a vehicle for wastes, and without having to deal with nutrients while making electrolyte and volume adjustments.

Which of the following substances is not normally found in filtrate?

blood cells and large particles Yes, both blood cells and large particles, such as proteins, are not allowed to filter through a healthy glomerular membrane.

Which of the choices below is not a method by which the cells of the renal tubules can raise blood pH?

by secreting sodium ions

The __________ collect(s) urine, which drains continuously from the papillae; the urine is then emptied into the __________

calyces; renal pelvis Formed urine enters into the renal calyces and then the renal pelvis before entering the ureter.

What is the function of the renal pelvis?

collects newly formed urine The minor calyces of the renal pelvis collect newly formed urine as it exits the renal papillae.

The function of angiotensin II is to ________.

constrict arterioles and increase blood pressure

Which structure is highlighted?

cortical nephron

External chemicals that enhance urinary output are called __________.

diuretics Chemicals such as alcohol and prescription drugs are external chemicals that enhance urinary output.

Which structure is highlighted?

external urethral orifice

The __________ is a skeletal muscle under conscious control that allows urine to leave the bladder.

external urethral sphincter The external urethral sphincter is made of skeletal muscle. As you recall, skeletal muscle is primarily controlled consciously. As such, a person during sleep would automatically leak urine, just as he might drool on his pillow, if it were left up to a consciously controlled muscle.

Which is a function of the collecting ducts?

form a large volume of very dilute urine or a small volume of very concentrated urine

Which capillary bed produces filtrate?

glomerulus The glomerulosa (capillary bed) in the glomerular capsule produces filtrate due to the high fluid pressure within the vessels.

What two structures constitute the renal corpuscle?

glomerulus and glomerular (Bowman's) capsule The glomerulus and glomerular (Bowman's) capsule constitute the renal corpuscle. This is where filtrate is removed from the blood.

Which of these should NOT normally appear in urine?

glucose. glucose would normally be completely reabsorbed during urine formation and should not be in a urine sample.

What is the most direct function of the juxtaglomerular complex?

help regulate blood pressure and the rate of blood filtration by the kidneys

What is the chief force pushing water and solutes out of the blood and across the filtration membrane of the glomerulus?

hydrostatic pressure in glomerular capillaries (HPgc) While diffusion rates are affected more by osmotic differences and concentration gradients, hydrostatic pressure in glomerular capillaries (HPgc) is the chief method of forcing water and solutes by filtration.

What is the primary driving force (pressure) that produces glomerular filtration?

hydrostatic pressure of blood (blood pressure)

Cells and transport proteins are physically prevented from passing through the filtration membrane. This has the following effect on filtration.

increasing osmotic pressure in the glomerular capillaries that reduces the amount of filtration

The fatty tissue surrounding the kidneys is important because it ________

it stabilizes the position of the kidneys by holding them in their normal position

Which organ(s) is/are highlighted?

kidneys

The functional and structural unit of the kidneys is the ________

nephron

Which pressure accounts for the other three?

net filtration pressure Net filtration pressure is a combination of glomerular hydrostatic pressure minus capsular hydrostatic pressure and colloidal osmotic pressure.

If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease?

net filtration would decrease Yes, because osmotic pressure opposes filtration, increasing osmotic pressure would decrease net filtration.

The mechanism of water reabsorption by the renal tubules is ________

osmosis

Which substance would be found in higher concentration if the membrane were damaged?

protein Yes, large proteins are not normally filtered by a healthy glomerular membrane.

Where does the kidney filter the blood?

renal corpuscle (The renal corpuscle is an interface between the blood supply and the kidney. It consists of the glomerulus, which is a capillary bed, and the glomerular (bowman's) capsule, which is part of the nephron. Filtration is the exit of small substances from the blood in the glomerulus into the glomerular capsule of the nephron.)

In which kidney region are all renal corpuscles located?

renal cortex All renal corpuscles are located in the renal cortex. The glomerular capsule wraps around the glomerulus, whose blood source is the cortical radiate artery.

Which of the following regions of the kidney is in contact with the fibrous capsule?

renal cortex The fibrous capsule encloses the kidney. It is in contact with the renal cortex.

Reabsorption of high levels of glucose and amino acids in the filtrate is accomplished by ________.

secondary active transport

What defines the trigone of the urinary bladder?

the ureter entrances and the opening to the urethra The ureter entrances and the opening to the urethra define the trigone of the urinary bladder, which is found in both males and females.

The urinary bladder is composed of ________ epithelium.

transitional

What type of epithelium lines the highlighted structure?

transitional

Which epithelial type is highlighted?

transitional epithelium

In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water. T/F

true

Which structure is highlighted?

urinary bladder