Chapter 23 Urinary

Front 1

List the main structures composing the urinary system.

Back 1

The main structures of the urinary system are the kidneys, ureters, urinary bladder, and urethra.

Front 2

Describe the concentric layers of connective tissue that protect and anchor the kidney.

Back 2

The layers of connective tissue that protect and anchor the kidney are the fibrous capsule, the perinephric fat capsule, and the renal fascia. The fibrous capsule covers the surface of the kidney, the perinephric fat capsule is a thick layer of adipose tissue surrounding the fibrous capsule, and the renal fascia is a dense, fibrous outer layer that anchors the kidney to surrounding structures.

Front 3

What would happen to a kidney's position if the perinephric fat layer were depleted and the collagen fibers of the fibrous capsule were to become detached?

Back 3

If the perinephric fat, which helps against the posterior body wall, were depleted, the kidneys could drop (a condition called renal ptosis) and would no longer be held securely; disruption of the collagen fibers could create a condition called floating kidney, which may cause pain or distortion of other structures.

Front 4

Which structure is a conical mass within the renal medulla that ends at the papilla?

Back 4

The renal pyramid is a conical mass within the renal medulla that ends at the papilla.

Front 5

Describe the renal papilla.

Back 5

The renal papilla is the tip of the conically shaped renal pyramid; it empties formed urine into the renal pelvis.

Front 6

Which type of nephron is essential for the conservation of water and the production of concentrated urine?

Back 6

Juxtamedullary nephrons are essential for the conservation of water and the production of concentrated urine.

Front 7

List the primary structures of the nephron and collecting system.

Back 7

The primary structures of the nephron are the renal corpuscle, proximal convoluted tubule, nephron loop, and distal convoluted tubule. The main structures of the collecting system are the collecting duct and papillary duct.

Front 8

Identify the components of the renal corpuscle.

Back 8

The renal corpuscle consists of the glomerular capsule and the glomerulus.

Front 9

What is the difference between fluid formed in the glomerulus and blood plasma?

Back 9

Glomerular fluid (also called filtrate) essentially lacks proteins, whereas blood plasma contains a variety of larger protein molecules.

Front 10

Trace the pathway of blood from the renal artery to the renal vein.

Back 10

Pathway of renal blood flow: renal artery-> segmental arteries-> interlobar arteries-> arcuate arteries-> cortical radiate arteries-> afferent arterioles-> glomerulus-> efferent arterioles-> peritubular capillaries-> cortical radiate veins-> arcuate veins-> interlobar veins-> renal vein

Front 11

Describe how blood enters and leaves the glomerulus.

Back 11

Blood enters the glomerulus via the afferent arteriole and leaves via the efferent arteriole.

Front 12

What are the vasa recta?

Back 12

The vasa recta are long, straight peritubular capillaries that parallel the nephron loop of a juxtamedullary nephron.

Front 13

Identify the three distinct processes of urine formation in the kidney.

Back 13

The three distinct processes of urine formation in the kidney are filtration, reabsorption, and secretion.

Front 14

Where does filtration exclusively occur in the kidney?

Back 14

Filtration exclusively occurs across the filtration membrane in the renal corpuscle.

Front 15

What occurs when the plasma concentration of a substance exceeds the kidney's capacity for transporting that substance?

Back 15

When the plasma concentration of a substance exceeds the kidney's capacity for transporting that substance, the excess is not reabsorbed, so it is excreted in the urine.

Front 16

The capsular space separates which layers of the glomerular capsule?

Back 16

The capsular space separates the parietal and visceral layers of the glomerular capsule.

Front 17

Explain why blood pressure is higher in glomerular capillaries than in other systemic capillaries.

Back 17

The primary factor is the balance between hydrostatic pressure (fluid pressure) and colloid osmotic pressure (pressure due to materials in solution) on either side of the capillary walls.

Front 18

Blood colloidal osmotic pressure tends to draw water out of the filtrate and into the plasma. Why does this occur?

Back 18

Blood colloidal pressure tends to draw water out of the filtrate and into the plasma because the solute concentration within the blood exceeds that within the filtrate. The "advantage" that results when blood colloidal pressure draws water out of the filtrate and into the plasma is that this action helps conserve body water.

Front 19

In response to decreased filtration pressure, the juxtaglomerular complex does what?

Back 19

in response to decreased filtration pressure, the juxtaglomerular complex increases renin production and release into the bloodstream.

Front 20

Angiotensin 2 has what effect on nephrons?

Back 20

Angiotensin 2 causes efferent arteriole constriction, which increases glomerular blood pressure.

Front 21

Angiotensin 2 has what effect on the CNS?

Back 21

Angiotensen 2 triggers CNS neural responses, including enhancing the sensation of third and increasing ADH production.

Front 22

Identify the segment of the nephron that makes final adjustments to the composition of tubular fluid.

Back 22

The distal convoluted tubule (DCT) makes final adjustments to the composition of tubular fluid.

Front 23

What effect would increased amounts of aldosterone have on the K⁺ concentration in urine?

Back 23

Increased amounts of aldosterone, which promotes Na⁺ retention and K⁺ secretion at the kidneys, would elevate the K⁺ concentration or urine.

Front 24

What effect would a decrease in the Na⁺ concentration of filtrate have on the pH of tubular fluid?

Back 24

If the concentration of Na⁺ in the filtrate decreased, fewer hydrogen ions could be secreted via the countertransport mechanism involving these two ions. As a result, the pH of the tubular fluid would increase.

Front 25

Define countercurrent multiplication as it occurs in the kidneys.

Back 25

Countercurrent multiplication in the kidneys is the exchange of substances between two adjacent nephron loop limbs containing fluid moving in opposite directions; the process is responsible for the kidney tubules' ability to concentrate urine.

Front 26

The thick ascending limb of the nephron loop actively pumps what substances into the peritubular fluid?

Back 26

The thick ascending limb actively pumps sodium and chloride into the peritubular fluid; it is impermeable to water.

Front 27

An increase in sodium and chloride ions in the peritubular fluid affects the descending limb in what way?

Back 27

An increase of sodium and chloride ions in the peritubular fluid elevates the osmotic concentrations around the descending limb, resulting in the osmotic flow of water out of it.

Front 28

Can the permeability of the PCT or DCT ever change? Why or why not?

Back 28

No, permeability of the PCT cannot change, and water reabsorption occurs whenever the osmotic concentration of the peritubular fluid exceeds that of the tubular fluid.

Front 29

What effects does an increase in ADH levels have on the DCT?

Back 29

Increased ADH levels cause the appearance of more water channels, or aquaporins, in the DCT; as a result, more water is reabsorbed into the peritubular fluid, which reduces the volume of water in the urine.

Front 30

When ADH levels in the DCT decrease, what happens to the urine osmotic concentration?

Back 30

Decreasing ADH levels in the DCT reduce the urine osmotic concentration due to the presence of more water in the urine; the result is a larger volume of more dilute urine.

Front 31

The filtrate produced at the renal corpuscle has the same osmotic pressure as ____________?

Back 31

The filtrate produces at the renal corpuscle has the same osmotic pressure as plasma.

Front 32

In the PCT, ions and organic substrates are actively removed, thus causing what to occur?

Back 32

The active removal of ions and organic substrates from the PCT causes a continuous osmotic flow of water out of the tubular fluid.

Front 33

How is the concentration gradient of the renal medulla maintained?

Back 33

The concentration of gradient of the renal medulla is maintained by the removal of solutes and water from the area by the vasa recta, which transport them to the circulatory system.

Front 34

Define dialysis.

Back 34

Dialysis is the process of using an artificial semipermeable membrane to remove waste products from the blood of a person whose kidneys are not functional properly.

Front 35

Briefly explain the difference between chronic renal failure and acute renal failure.

Back 35

Chronic renal failure involves a gradual loss of renal function, whereas acute renal failure involves a sudden loss of renal function.

Front 36

Explain why patients on dialysis often receive Epogen or Procrit, a synthetic form of erythropoietin.

Back 36

Patients on dialysis are often given Epogen or Procrit (a synthetic form of erythropoietin) to treat anemia, which occurs because their malfunctioning kidneys produce too little erythropoietin, the hormone that stimulates the development of red blood cells in the bone marrow.

Front 37

Urine is transported by the ___________ stored within the ______________, and eliminated through the ___________.

Back 37

Urine is transported by the ureters, stored within the urinary bladder, and eliminated through the urethra.

Front 38

The wall of the urinary bladder is composed of a specialized smooth muscle. Name it and describe its physiological role.

Back 38

The specialized smooth muscle in the wall of the urinary bladder is the detrusor muscle; its contraction compresses (squeezes) the urinary bladder and expels urine into the urethra.

Front 39

What has to happen to the external urethral sphincter to allow urination?

Back 39

The external urethral sphincter must be consciously relaxed to allow urination.

Front 40

The sensation of a full bladder is relayed from the bladder to the thalamus to the ______________.

Back 40

The sensation of a full bladder is relayed from the bladder to the thalamus to the cerebral cortex.

Front 41

Voluntary relaxation of the external urethral sphincter causes relaxation of the internal urethral sphincter via what mechanism?

Back 41

Voluntary relaxation of the external urethral sphincter causes relaxation of the internal urethral sphincter via the micturition reflex.

Front 42

Describe the micturition reflex.

Back 42

The urge to urinate usually appears when the urinary bladder contains about 200mL of urine. The micturition reflex begins to function when the stretch receptors have provided adequate stimulation to the parasympathetic motor neurons. The activity in the motor neurons generates action potentials that reach the smooth muscle in the wall of the urinary bladder. These efferent impulses travel over the pelvic nerves, producing a sustained contraction of the urinary bladder.

Front 43

What is the term for painful or difficult urination?

Back 43

Dysuria is the term for painful or difficult urination.

Front 44

Obstruction of a ureter by a kidney stone would interfere with the flow of urine between which two points?

Back 44

Obstruction of a ureter by a kidney stone would interfere with the flow of urine between the kidney and the bladder.

Front 45

Why is urinary obstruction at the urethra more dangerous than at the ureter?

Back 45

Urinary obstruction at the urethra is more dangerous than urinary obstruction in the ureter because urine would be prevented from exiting the body and would build up in the urinary bladder, leading to rupture. Obstruction of only one of the two ureters is less hazardous than obstruction of the lone urethra because in the former case, the other kidney could still excrete wastes that could be voided.