Urinary System

Because each kidney contains approximately six square meters of filtration surface, the glomerular filtration rate (GFR) averages

125 milliliters/minute.

Urine ejection cannot occur unless which event(s) takes place?

Both the internal and external urethral sphincters are relaxed.

What effect does epinephrine have on the urinary system?

It leads to increased blood pressure.

What will likely occur if glomerular blood pressure falls significantly?

Kidney filtration will stop.

If circulating levels of antidiuretic hormone (ADH) are low, then

Little water reabsorption will occur and virtually all of the water reaching the DCT will be lost in the urine.

When one eats a high-sodium meal, why does it not raise the sodium ion concentration of body fluids?

Osmosis moves water from the digestive epithelium to the ECF.

_____ is the transport of solutes from the peritubular capillaries, across the tubular epithelium, and into the filtrate.

Secretion

Water moves from the cells into the ECF if

The ECF becomes hypertonic with respect to the ICF.

Why does the peritubular fluid of the renal medulla contain an unusually high solute concentration?

The ascending limb of the nephron loop actively transports sodium and chloride ions out of the tubular fluid.

If pH increases in a protein buffer system, what is most likely to occur?

The carboxyl group of the amino acid dissociates, releasing a hydrogen ion.

What is correct about the location of the kidney(s)?

The kidneys are bilateral and retroperitoneal.

What is true regarding the general characteristics of normal urine?

The osmolarity of normal urine ranges from 855 - 1335 mOsm/L.

What is true regarding the extracelullar fluid (ECF) and the intracellular fluid (ICF).

The osmotic concentrations of the ICF and ECF are identical.

If through injury, both the blood flow to the kidneys and the glomerular filtration pressure decrease, what will likely occur?

The renin-angiotensin system will be activated.

If the extracellular fluid (ECF) becomes hypotonic with respect to the intracellular fluid (ICF), what event will likely occur?

Water will move from the ECF into the cells.

The renal pyramid is

a conical-shaped structure that is located in the renal medulla.

The primary function of the proximal convoluted tubule is

absorption of ions, organic molecules, vitamins, and water.

Electrolyte balance primarily involves balancing the rates of ________ across the digestive tract with rates of ________ at the kidneys.

absorption; loss

Where does exchange among the subdivisions of the ECF primarily occur?

across the endothelial lining of capillaries

What is a primary function of the distal convoluted tubule?

active secretion of ions, acids, drugs, and toxins

Throughout most of the distal convoluted tubule, the tubular cells

actively transport sodium ions out of the tubular fluid.

Potassium ion secretion along the distal convoluted tubule and collecting duct is stimulated by

aldosterone.

The vasa recta

are long, straight capillaries that parallel the nephron loop deep into the renal medulla.

The actions of which hormone cause a decrease in the rate of sodium ion reabsorption in the DCT, leading to increased urinary sodium ion loss?

atrial natriuretic peptide

Renal columns are

bands of the renal cortex that extend toward the renal sinus.

If the peripheral capillary beds become constricted,

blood pressure in the renal arteries will increase.

ANP release is stimulated when

blood volume and blood pressure are too high.

The most important factor affecting the pH of body fluids is the concentration of

carbon dioxide.

ADH is released by cells in the

central nervous system.

What are the principal anions in the ECF?

chloride and bicarbonate

Regulation of the amounts of water, sodium ions, and potassium ions lost in the urine occurs between the nephron loop and the

collecting system.

The detrusor muscle

compresses the urinary bladder and expels urine through the urethra.

A reduction in blood flow and a decline in glomerular filtration pressure triggers

constriction of the efferent arteriole

What metabolic waste product is generated in skeletal muscle tissue through the breakdown of a high-energy compound?

creatinine

Inflammation of the lining of the bladder is called

cystitis.

Roughly 98% of the potassium content of the body lies within

cytosol

What is a direct effect of sympathetic activation on kidney function?

decreased glomerular filtration rate

ADH promotes increased water permeability of the

distal convoluted tubule.

The portion of the nephron that attaches to the collecting system is the

distal convoluted tubule.

Major calyces are

drains that combine to form the renal pelvis.

Filtration is the process in which

fluid and dissolved solutes are forced out of the glomerular capillaries.

Water movement between the ECF and ICF is called

fluid shift.

The cup-shaped chamber, or the expanded end of a nephron, is known as the

glomerular capsule.

Which process is the vital first step essential to all kidney functions?

glomerular filtration

What are components of a renal corpuscle?

glomerulus and glomerular capsule

The renal ________ is the site at which the renal artery and renal nerve enter and the renal vein exits.

hilum

A 72-year-old male patient complains of having difficulty while urinating. A very likely explanation may be that

his prostate is enlarged and compresses the urethra.

What is the characteristic treatment for respiratory acidosis?

improve ventilation

The term incontinence refers to the

inability to control urination voluntarily.

With increasing age,

instances of kidney problems increase.

What component of the ECF is the largest in both males and females?

interstitial fluid

What endocrine structures secretes the hormone erythropoietin and the enzyme renin?

juxtaglomerular complex

What organs play key roles in maintaining the acid-base balance of body fluids?

kidneys and lungs

Any condition accompanied by severe kidney damage can result in ________, the second most common acid-base disorder.

metabolic acidosis

Repeated vomiting of stomach contents may result in which type of acid-base imbalance?

metabolic alkalosis

A person who is suffering from bouts of repeated vomiting may risk developing a serious case of

metabolic alkalosis.

Organic acids, or metabolic acids, are generated during the normal process of

metabolism.

What term is used to describe the process of urination?

micturition

Ducts within each renal papilla discharge urine directly into

minor calyx

When the level of ADH (antidiuretic hormone) increases,

more concentrated urine is produced.

Which organ system(s) is (are) particularly sensitive to pH changes?

nervous and cardiovascular systems

To achieve fluid balance, ion concentration gradients are eliminated by

osmosis.

Water reabsorption occurs passively through the process of

osmosis.

The visceral epithelium, which covers the glomerular capillaries of the glomerular capsule, consists of

podocytes.

Intracellular fluid contains an abundance of

potassium and phosphate.

The principal cation in the ICF is

potassium.

What is the primary role of the carbonic acid-bicarbonate buffer system?

prevent pH changes caused by organic (metabolic) acids

Management of renal failure involves restriction of water, salt, and protein intake. This approach helps to lessen the strain on the urinary system by

preventing the generation of large quantities of nitrogenous waste products.

The kidneys

produces urine

The hormone ANP

promotes the dilation of glomerular capillaries.

What region of the nephron and kidney collecting system functions in the reabsorption of ions, organic molecules, vitamins, and water?

proximal convoluted tubule

Reabsorption of glucose occurs mostly in the

proximal convoluted tubule.

If left untreated, a urinary tract infection may spread to the renal cortex and renal medulla resulting in

pyelonephritis.

The cells lining the proximal convoluted tubule

reabsorb organic nutrients, plasma proteins, and ions from the tubular fluid.

The ion pumps sensitive to aldosterone

reabsorb sodium ions from the tubular fluid.

By adjusting the volume of water lost in urine, and releasing erythropoietin and renin, the urinary system specifically functions in

regulating blood pressure.

In which part of the kidney are the renal corpuscles located?

renal cortex

In which renal component does urine production begin?

renal cortex

The large, funnel-shaped chamber that connects to the ureter is called the

renal pelvis.

Hypoventilation is usually the cause of

respiratory acidosis.

Considering the spatial relationship of the kidneys, the ________ kidney often sits slightly ________ than the ________ kidney.

right; lower; left

The micturition reflex center consists of afferent sensory fibers in the pelvic nerves, which carry the resulting impulses to the

sacral spinal cord.

The kidneys can compensate for a drop in blood pH by

secreting H+ and reabsorbing HCO3-.

Which of the following is aldosterone able to affect?

sodium retention

The most abundant cation in the ECF is

sodium.

The intracellular fluid (ICF) is found in

the cytosol.

Regarding sodium balance, what is the most important site(s) for regulating sodium ion losses?

the kidneys

The process for regulating pH that plays only a supporting role in the ECF but is quite important in pH control of the ICF is

the phosphate buffer system.

Acid-base balance exists when

the production of hydrogen ions is equal to their loss.

In response to respiratory alkalosis,

the respiratory rate decreases.

The micturition reflex begins to function when

the stretch receptors have provided adequate stimulation to the parasympathetic motor neurons.

When the level of potassium ions in the ECF increases,

there is an increase in the level of aldosterone.

The ureters and urinary bladder are lined by

transitional epithelium.

In the nephron loop,

two-thirds of the sodium and chloride ions remaining in the tubular fluid are reabsorbed.

What transports urine from the kidney toward the bladder?

ureter

Organs of the urinary system that are actively involved with urine transport are the

urethra and ureters

Urine is temporarily stored by the

urinary bladder.

In response to decreased levels of aldosterone, the kidneys would likely produce

urine with a higher concentration of sodium ions.

What blood vessel surrounds the nephron loop of a juxtamedullary nephron?

vasa recta

At the nephron, angiotensin II triggers ________ to elevate glomerular pressures and glomerular filtration rates.

vasoconstriction of the efferent arterioles