Urinary System II

Question 1

When the sodium and chloride concentrations in the DCT are too high, cells in the
juxtaglomerular apparatus called _____ cells secrete a chemical signal which causes the
_____, allowing more time for ion resorption.

Answer 1

macula densa; afferent

arteriole to constrict

Question 2

When the filtrate flow in the DCT is too low or the filtrate is too dilute, cells in the
juxtaglomerular apparatus called _____ cells STOP secreting a chemical signal which
causes the _____. As a result, GFR increases.

Answer 2

macula densa; afferent

arteriole to constrict

Question 3

When the filtrate flow in the DCT is too low or the filtrate is too dilute, cells in the
juxtaglomerular apparatus called _____ cells secrete renin, which indirectly causes a(n)
_____ in systemic blood pressure.

Answer 3

juxtaglomerular (JG); increase

Question 4

When blood pressure in the afferent and efferent arterioles is insufficient, cells in the
juxtaglomerular apparatus called _____ cells secrete renin, which indirectly causes a(n)
_____ in systemic blood pressure and indirectly _____.

Answer 4

juxtaglomerular (JG); increase;

increases sodium retention

Question 5

Renin hydrolyses angiotensinogen to angiotensin I which is converted to _____ by ACE.
This in turn stimulates _____ and also production of _____.

Answer 5

angiotensin II; vasoconstriction;

aldosterone

Question 6

Aldosterone, released by the cortex of the _____, _____ blood pressure by causing
_____ and thus (by osmosis) _____.

Answer 6

adrenal glands; increases;
sodium retention; water
retention

Question 7

Angiotensin II increases systemic blood pressure by causing generalized vasoconstriction:
however, in the kidney, it affects the _____ arterioles more than the _____ ones, and so
GFP _____.

Answer 7

efferent; afferent; does not decrease

Question 8

During periods of intense stress, sympathetic signals to the afferent arterioles override the
kidney’s autoregulation and _____; thus, filtration is _____.

Answer 8

decrease blood flow to the

glomerulus; decreased

Question 9

Renal clearance tests measure the _____ per minute, and are used to diagnose
glomerular damage or monitor kidney disease.

Answer 9

volume of plasma from which a

solute is removed

Question 10

If a renal clearance test is done using a solute that enters the filtrate but which is neither
resorbed nor secreted by the nephron, then the renal clearance rate equals the _____.
(_____ is often administered and used for this purpose.)

Answer 10

glomerular filtration rate (GFR);

Inulin

Question 11

. Most solutes and water are resorbed in the _____.

Answer 11

PCT

Question 12

Most or all of the organic nutrients such as glucose which are present in the filtrate are
_____.

Answer 12

resorbed in the PCT

Question 13

Resorption of sodium and potassium is controlled by _____.

Answer 13

aldosterone

Question 14

Resorption of calcium is controlled by _____; it is not unusual, in that the resorption of
most minerals is _____.

Answer 14

PTH; hormonally controlled

Question 15

Water resorption is regulated by two hormones, _____ and _____: both of these act only
on the _____ and _____.

Answer 15

aldosterone; ADH; DCT;

collecting duct

Question 16

Most resorption involves the movement of molecules _____ the tubule cells. This, in turn,
almost always requires the presence of _____ in the cell membrane.

Answer 16

through; carrier proteins

Question 17

Under certain conditions, so much of a particular solute may be present in the filtrate that
the _____ responsible for its resorption aren’t sufficient for the task. In such cases, the
concentration in the plasma is said to be above the _____.

Answer 17

carrier proteins; renal threshold

Question 18

_____ join tubule cells to one another and prevent the passage of most substances
between cells; however, it is thought that water and a few ions are able to be resorbed by
this _____ route.

Answer 18

Tight junctions; paracellular

Question 19

A large volume of water is resorbed in the PCT, simply because the _____ creates
enough osmotic pressure to cause the water to follow. (Sodium in particular contributes to
this effect.)

Answer 19

transfer of solutes to the

interstitial fluid

Question 20

As water is resorbed in the PCT, the concentration of the solutes left behind _____. This
in turn makes it easier for them to be resorbed.

Answer 20

increases

Question 21

Water movements out of the proximal tubule and loop of Henle is driven by osmotic
pressure and sodium concentrations, and is referred to as _____ because it is not
regulated directly.

Answer 21

obligatory water resorption

Question 22

Water resorption in the DCT and collecting duct is hormonally controlled, and is referred
to as _____.

Answer 22

facultative water resorption

Question 23

Resorption of most substances in the PCT depends on a large _____ gradient between
the filtrate and the tubule cells. This gradient is created by _____ at the basal membrane.

Answer 23

sodium; sodium-potassium

ATPases

Question 24

Most substances in the PCT are resorbed using _____: that is, _____ enters the cell
along with the substance being resorbed, and in fact provides the driving force.

Answer 24

sodium cotransport; sodium

Question 25

_____ during solute resorption in the PCT directly involves ATP hydrolysis, and is the step performed by the _____. _____ occurs when energy stored in a gradient is used to transport a solute.

Answer 25

Primary active transport; sodium-potassium ATPase; Secondary active transport

Question 26

Solutes that have been resorbed leave the tubule cells via _____ or _____ diffusion.

Answer 26

simple; facilitated

Question 27

Water and solutes that have been resorbed enter the _____ and are carried from the kidney.

Answer 27

peritubular capillaries

Question 28

The concentration of a solution can be increased in either of two ways: _____ can be added or _____ can be removed.

Answer 28

solutes; solvent

Question 29

The major difference between the permeabilities of the descending and ascending loops of Henle is that the descending loop is permeable to _____ but not to _____, while the reverse is true in the ascending loop.

Answer 29

water; NaCl

Question 30

In the descending loop of Henle, the filtrate becomes _____ concentrated due to the removal of _____; in the ascending loop, it becomes _____ concentrated due to the removal of _____.

Answer 30

more; water; less; NaCl

Question 31

Removal of NaCl from the filtrate in the ascending loop of Henle requires _____.

Answer 31

active transport OR ATP

Question 32

_____ is able to diffuse from the collecting duct into the deep medullary tissue, contributing to the increasing osmotic gradient encountered by filtrate as it moves through the loop.

Answer 32

Urea

Question 33

In the medulla, the interstitial fluid is 4 times more concentrated near the _____ than near the _____. This allows juxtamedullary nephrons to produce urine that is _____.

Answer 33

renal papillae; cortex; very | concentrated

Question 34

By transporting the filtrate through a region of _____, the kidney maximizes the movement of water out of the filtrate due to osmosis.

Answer 34

high osmolarity

Question 35

Systems such as the vasa recta which rely on exchange between currents flowing in opposite directions in order to maintain a gradient are called _____.

Answer 35

countercurrent systems

Question 36

Blood enters the renal medulla in the descending branch of the _____, and loses _____ and gains _____ in the process. However, the gradient is not disturbed, because blood is carried out along the same route and these processes _____.

Answer 36

vasa recta; water; salt; reverse

Question 37

Although independent, secretion and resorption are not separated _____ (that is, they occur _____).

Answer 37

chronologically; together

Question 38

The sodium gradient used by the PCT to cotransport solutes during resorption can also be used for _____. In this process, a molecule or ion is secreted. The membrane protein performing the task is referred to as a(n) _____

Answer 38

countertransport; antiporter

Question 39

Some organic acids and bases (including some drugs) are secreted in the _____ and _____. These pathways are not specific, and so secretion of one generally competes with _____.

Answer 39

PCT; DCT; secretion of the | others

Question 40

The concentration of nitrogen-containing wastes (ammonium ions, urea and uric acid) in urine is increased by secretion in the _____, _____ and _____.

Answer 40

PCT; DCT; collecting duct

Question 41

In addition to their obvious function (collecting urine), collecting ducts in the kidney also control the concentration of the urine by changing their _____ in response to ADH.

Answer 41

permeability to water

Question 42

When the hypothalamus detects that the osmolarity of the blood is too high, _____ is released from the neurohypophysis to conserve water.

Answer 42

antidiuretic hormone

Question 43

ADH acts on the _____ to increase water permeability: this increases _____ water reabsorption.

Answer 43

DCT and collecting ducts; | facultative

Question 44

The heart produces _____, which reduces blood pressure, blood volume, and blood sodium concentration by inhibiting _____ release; it also dilates the afferent arteriole to increase _____ and inhibits sodium resorption in the DCT and collecting duct.

Answer 44

atrial natriuretic peptide or hormone (ANP or ANH); renin; GFR

Question 45

Solutes which exceed the _____ of their carriers (or in the case of some drugs, which are not recognized by any carriers) act as _____.

Answer 45

transport maximum; osmotic | diuretics

Question 46

Chemicals (drugs) which increase GFR, decrease water resorption, or increase the osmolarity of the filtrate reaching the collecting duct act as _____.

Answer 46

diuretics

Question 47

Calcium resorption is controlled by _____ hormone; in response to this hormone, calcium resorption in the _____ is increased.

Answer 47

parathyroid; DCT

Question 48

Aldosterone acts on the DCT and collecting duct to increase _____.

Answer 48

sodium resorption

Question 49

Excess potassium is toxic, and so secretion is sometimes necessary: this occurs in the _____ and _____ and is controlled by the hormone _____.

Answer 49

DCT; collecting duct; | aldosterone

Question 50

``` K+ and H+ ion secretion in the DCT and collecting ducts uses Na+ antiporters, and so an increase in Na+ transport out of the filtrate results in an increase in K+ or H+ ion transport _____. ```

Answer 50

into the filtrate

Question 51

An increase in plasma potassium levels results in the secretion of _____, which indirectly leads to secretion of potassium by the DCT and collecting duct.

Answer 51

aldosterone

Question 52

Hydrogen ions are secreted or resorbed (depending on the _____) in the _____, _____ and _____.

Answer 52

pH of the blood; PCT; DCT; | collecting duct

Question 53

Bicarbonate ions are secreted or resorbed (depending on the _____) in the _____.

Answer 53

pH of the blood; collecting duct

Question 54

Amino acids can be catabolized in the liver; but the nitrogen must be eliminated from the body. If blood pH is normal, the liver makes _____ (which contains two nitrogen atoms) to dispose of nitrogen.

Answer 54

urea

Question 55

Amino acids can be catabolized in the liver; but the nitrogen must be eliminated from the body. If blood pH is acidic, the liver transfers some of the nitrogen to glutamate to make _____.

Answer 55

glutamine

Question 56

If blood pH is acidic, the kidney uses nitrogen from _____ to form _____, which combines with a hydrogen ion and allows it to be disposed of in the urine

Answer 56

glutamine; ammonia

Question 57

The kidneys can secrete hydrogen ions in several ways: directly by _____ dependent primary active transport, by countertransport with _____, or in combination with _____ (whose secretion also depends on countertransport).

Answer 57

ATP; sodium; ammonia

Question 58

When peritubular cells in the kidney become hypoxic, they secrete _____ to stimulate the formation of more oxygen-carrying red blood cells.

Answer 58

erythropoietin

Question 59

Like the liver, the renal cortex can produce glucose from non-carbohydrate precursors. The kidney uses _____ as the starting material for this purpose. The process is called _____.

Answer 59

glutamine; gluconeogenesis

Question 60

Once the urine is formed, it leaves the kidneys and travels to the bladder through the _____, which are muscular tubes with three tissue layers: the lumenal _____, the _____, and the outer _____.

Answer 60

ureters; mucosa; muscularis; | adventitia

Question 61

The ureters enter the bladder at the base and at an angle. Because of this, increases in bladder pressure cause _____ which prevents _____.

Answer 61

the ureters to close; urine from being pushed back into the kidney

Question 62

The muscularis of the ureters contracts in _____.

Answer 62

peristaltic waves

Question 63

The bladder is a hollow, distensible ball of muscle lined with _____ and surrounded by a fibrous _____. (On its superior surface, the outer layer is actually the _____.) It stores urine until its disposal is convenient.

Answer 63

mucosa; adventitia; peritoneum

Question 64

The mucosa of the bladder consists of _____ epithelium, which allows it to stretch easily and far, supported by a(n) _____.

Answer 64

transitional; lamina propria

Question 65

The muscular layer which comprises the bulk of the bladder is the _____ muscle, and consists of _____ muscle whose fibers are arranged in three layers.

Answer 65

detrusor; smooth

Question 66

At the base of the bladder, the two ureteric openings and the urethral opening for a triangle: the region of the bladder encompassed by this triangle is called the _____

Answer 66

trigone

Question 67

Bladder distension is sensed by stretch receptors in the _____. Ordinarily, the urge to urinate is felt after _____ ml are present; this can be inhibited voluntarily, but it returns periodically as more urine enters the bladder.

Answer 67

detrusor muscle; ~200

Question 68

The maximum bladder capacity is 3/4 to 1 liter; if circumstances force urine retention to (or above) this level, urination _____ or (much more serious) _____.

Answer 68

may occur involuntarily; the bladder may burst (especially if an abdominal impact occurs)

Question 69

Urine leaves the bladder through the _____. This tube is _____ times longer in males than in females.

Answer 69

urethra; five

Question 70

Urine is prevented from leaving the bladder prematurely by two rings of muscle: one is the voluntarily controlled _____, which can be assisted by contraction of the _____.

Answer 70

external urethral sphincter; | levator ani

Question 71

Urine is prevented from leaving the bladder prematurely by two rings of muscle: the involuntary _____ is formed continuous with the detrusor muscle.

Answer 71

internal urethral sphincter

Question 72

In females, the outer urethral opening is immediately _____ to the vaginal opening

Answer 72

anterior

Question 73

In males, the urethra has three regions: the _____ urethra just under the bladder, the _____ urethra within the penis, and the _____ urethra which connects them.

Answer 73

prostatic; spongy OR penile; | membranous

Question 74

_____ is another word for urination.

Answer 74

Micturition

Question 75

The lowest level of bladder control, and first to develop, is the _____: filling of the bladder sends a signal to the sacral spinal cord, and an efferent signal is sent in response which triggers _____.

Answer 75

sacral micturition reflex; | micturition

Question 76

As development progresses, the sacral micturition reflex comes under the control of the _____, which is located in the pons.

Answer 76

pontine micturition center

Question 77

The micturition center in the _____ inhibits the pontine micturition center in the _____ to prevent socially inappropriate urination, but this control does not develop until 2-4 years of age.

Answer 77

frontal lobe; pons

Question 78

Bladder filling is an active process which depends on sympathetic fibers which leave the spinal cord in the _____. These inhibit the detrusor muscle and excite the internal urethral sphincter, allowing _____.

Answer 78

lumbar region; the bladder to | stretch

Question 79

_____ control the contraction and relaxation of the external sphincter in response to signals from the _____ and from the stretching of the _____.

Answer 79

Sacral nerves; pons OR pontine micturition center; detrusor muscles

Question 80

Contraction of the detrusor muscle (which is necessary to fully empty the bladder) is controlled by _____.

Answer 80

sacral nerves

Question 81

_____ carry most of the afferent signals of detrusor stretch; if the spinal cord is intact, these signals are relayed to the pons and from there to higher brain regions.

Answer 81

Sacral nerves

Question 82

Involuntary urination is called urinary incontinence. If it occurs only in small volumes when the bladder is placed under pressure, it is _____. If it is due to involuntary contractions of the detrusor muscle, it is _____.

Answer 82

stress incontinence; urge | incontinence

Question 83

Normally, urine is sterile. If bacteria invade the urinary system, the infection is called a(n) _____.

Answer 83

urinary tract infection (UTI)

Question 84

Inflammation of components of the urinary system is common in response to bacterial or fungal infections: _____ is inflammation of the bladder.

Answer 84

cystitis

Question 85

Inflammation of components of the urinary system is common in response to bacterial or fungal infections: _____ is inflammation of the urethra.

Answer 85

urethritis

Question 86

_____ is inflammation that results when an infection reaches the pyelum (pelvis) of the kidney.

Answer 86

Pyelonephritis

Question 87

Various health and dietary factors may lead to the formation of _____, which if small may pass on their own (with much pain!) or if large may require medical intervention.

Answer 87

kidney stones OR renal calculi

Question 88

_____ refers to an abnormally low rate of urine formation caused by low _____ or kidney _____.

Answer 88

Anuria; glomerular hydrostatic | pressure (HPg); disease