Advertisement Upgrade to remove ads

The Urinary System/ Electrolyte balance

Where in the nephron does most solute reabsorption occur?

proximal convoluted tubule

Approximately 80% of the energy used for active transport is devoted to the reabsorption of __________.

sodium

What is the juxtaglomerular apparatus?

a system that regulates the rate of filtrate formation and systemic blood pressure

Most solutes that are reabsorbed in the proximal convoluted tubule use which of the following pathways?

transcellular

During reabsorption of water in the proximal convoluted tubule, what causes water to diffuse from the lumen into the interstitial space?

an increase in the osmolarity of the interstitium

The decreased intracellular concentration of sodium in tubular cells during active transport is caused by which of the following mechanisms?

the sodium-potassium ATPase pump in the basolateral membrane

The active transport of which ion out of proximal convoluted tubule cells causes the reabsorption of both water and solutes?

sodium

Which of the following transporters in the luminal membrane results in secretion?

Na+-H+ countertransport

What is the limiting factor for the reabsorption of most actively transported solutes in the proximal tubule?

number of transport carriers in the luminal membrane

Which of the following best describes glomerular filtration rate (GFR)?

the volume of filtrate created by the kidneys per minute

GFR regulation mechanisms primarily affect which of the following?

glomerular hydrostatic pressure (HPg)

Which of the following are mechanisms of intrinsic control of glomerular filtration (renal autoregulation)?

myogenic mechanism and tubuloglomerular feedback

Macula densa cells of the juxtaglomerular apparatus (JGA) regulate GFR through which intrinsic mechanism?

tubuloglomerular feedback

The myogenic mechanism of renal autoregulation primarily involves smooth muscle in which blood vessels?

afferent arterioles

What does a high concentration of NaCl in the renal tubule at the juxtaglomerular apparatus (JGA) most likely indicate?

insufficient NaCl reabsorption due to high GFR

Through the tubuloglomerular feedback mechanism, how would an increase in filtrate NaCl concentration affect afferent arteriole diameter?

Afferent arteriole diameter would decrease.

Granular cells of the juxtaglomerular apparatus (JGA) regulate GFR through which mechanism?

renin-angiotensin mechanism

Which hormone(s) is/are required for facultative water reabsorption in the collecting ducts?

ADH

A nonfasting urine sample from an individual who has previously ingested donuts and a soft drink showed the presence of sugar (glucose). Which of the following statement explains the presence of the glucose in the urine?

The individual exceeded the transport maximum

Which part of the brain controls the micturition reflex?

pons

The __________ keeps the urethra closed when urine is not being passed from the bladder and prevents leaking between voiding.

internal urethral sphincter

Since most patients with renal failure produce little or no urine, hemodialysis often involves removal of water from the blood. However, side-effects may develop if too much fluid is removed from the blood. Which of the following is NOT one of the potential side-effects?

vasoconstriction of afferent arterioles

The frequency of cystitis in men is lower than in women because ______.

the male urethra is longer than the female urethra

Urinary incontinence may occur if a person has ______.

an overactive detrusor muscle

T/F: Having a kinked ureter is called renal ptosis.

False

T/F: The proximal convoluted tubule is the portion of the nephron that attaches to the collecting duct.

False

T/F: The entire responsibility for urine formation lies with the nephron.

True

Which cells of the kidney are chemoreceptors that respond to changes in solute content of the filtrate?

macula densa cells

Which of the choices below is the salt level-monitoring part of the nephron?

macula densa

What is the most direct function of the juxtaglomerular apparatus?

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

Which of the following is not a part of the juxtaglomerular apparatus?

podocyte cells

Select the correct statement about the nephrons.

The parietal layer of the glomerular capsule is simple squamous epithelium.

The macula densa cells respond to ________.

changes in solute content of the filtrate

The filtration membrane includes all except ________.

renal fascia

The fatty tissue surrounding the kidneys is important because it ________.

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

The glomerulus differs from other capillaries in the body in that it ________.

is drained by an efferent arteriole

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

arcuate

Which of the following is the most likely to cause pyelonephritis?

infection of the urinary bladder

Hydronephrosis may be caused by all EXCEPT which of the following?

renal failure

T/F: The macula densa cells are chemoreceptors that respond to changes in the urea content of the filtrate.

False

T/F: Atrial naturetic peptide inhibits sodium reabsorption.

True

T/F: Tubular secretion is effective in controlling blood pH.

True

T/F: An excessive urine output is called anuria.

False

T/F: The myogenic mechanism reflects the tendency of vascular smooth muscle to stretch.

False

T/F: Urea is reabsorbed in the loop of Henle.

False

T/F: Blood pressure in the renal glomerulus is lower than in most parts of the body in order to conserve body water.

False

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

True

T/F: The collecting duct is impermeable to water in the presence of ADH.

False

T/F: Glomerular filtration is an ATP-driven process.

False

T/F: Water reabsorption through the proximal convoluted tubule is termed obligatory water reabsorption, whereas water reabsorption through the distal convoluted tubule is termed facultative water reabsorption

True

T/F: 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.

False

Which of the choices below are the most important hormone regulators of electrolyte reabsorption and secretion?

angiotensin II and aldosterone

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

ADH

In the ascending limb of the loop of Henle the ________.

thick segment moves ions out into interstitial spaces for reabsorption

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

Excretion of dilute urine requires ________.

impermeability of the collecting tubule to water

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

secondary active transport

Which of the following is not true regarding tubular reabsorption?

It is a purely passive transport process

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

A disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland with symptoms of polyuria is ________.

diabetes insipidus

Alcohol acts as a diuretic because it ________.

inhibits the release of ADH

Which of the following is not reabsorbed by the proximal convoluted tubule?

creatinine

The mechanism of water reabsorption by the renal tubules is ________.

osmosis

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

eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat

An increase in the permeability of the cells of the collecting tubule to water is due to a(n) ________.

increase in the production of ADH

The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________.

loop of Henle

T/F: Blood in the urine may be a symptom of bladder cancer.

True

If one says that the clearance value of glucose is zero, what does this mean?

Normally all the glucose is reabsorbed

An important characteristic of urine is its specific gravity or density, which is ________.

slightly higher than water (1.001-1.035)

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

False

T/F: Fetal kidneys have the primary responsibility of clearing wastes from the fetal blood.

False

Polycystic kidney disease always affects both kidneys instead of only the right or left kidney because ______.

it is a genetic disease

T/F: Incontinence is the inability to control voluntary micturition

True

T/F: The urethra contains an internal sphincter of smooth muscle.

True

T/F: The act of emptying the bladder is called voiding.

True

Select the correct statement about urinary system development.

Kidneys develop from urogenital ridges

.

Fetal kidneys do not have to work very hard because

the placenta allows the mother's urinary system to clear the waste from fetal blood.

Under normal circumstances, most water is lost in __________.

urine

The role of ADH is to __________.

increase water reabsorption

The body's water volume is closely tied to a powerful water "magnet." What magnet is referred to here?

ionic sodium

Which of the following is NOT a hormone involved in water and electrolyte balance?

thyroxine

Which hormone raises blood calcium levels?

PTH

Which buffer system is the most abundant in the body?

protein

What is the effect of hyperventilation on pH?

respiratory alkalosis

Which age group most commonly has fluid, electrolyte, and acid-base balance issues?

infants

T/F: Solutes, regardless of size, are able to move freely between compartments because water carries them along the osmotic gradients.

False

T/F: Electrolytes determine most of the chemical and physical reactions of body fluids.

True

T/F: The most abundant cation in intracellular fluid is sodium.

False

T/F: Adipose tissue is one of the most hydrated of all tissues in the human body.

False

The most important force causing net water flow across capillary walls is ________.

hydrostatic pressure of capillary blood

Which of the following statements is true regarding fluid shifts?

Electrolytes have greater osmotic power than nonelectrolytes and therefore have the greatest ability to cause fluid shifts

The movement of fluids between cellular compartments ________.

is regulated by osmotic and hydrostatic forces

Which of the following describes the distribution of sodium and potassium between cells and body fluids?

K+ mainly in the cells, Na+ in the body fluids

Whereas sodium is found mainly in the extracellular fluid, most ________ is found in the intracellular fluid.

potassium

T/F: Thirst is always a reliable indicator of body water need.

False

T/F: To remain properly hydrated, water intake must equal water output.

True

T/F: Water imbalance, in which output exceeds intake, causing an imbalance in body fluids, is termed dehydration.

True

T/F: It is impossible to overhydrate because people need as much water as they can drink to carry out ordinary body functions.

False

T/F: Dehydration can be caused by endocrine disturbances such as diabetes mellitus or diabetes insipidus.

True

T/F: The thirst center in the brain is located in the hypothalamus

True

One of the major physiological factors that triggers thirst is ________.

a rise in plasma osmolality

Which of the following hormones is important in stimulating water conservation in the kidneys?

antidiuretic hormone

T/F: Carotid artery and aortic baroreceptors are involved in long term adjustment to total body sodium ion content

True

T/F: The two hormones responsible for the regulation of calcium are pituitary hormone and calcitonin.

False

T/F: Hypercalcemia causes muscle tetany.

False

T/F: Premenstrual edema may be due to enhanced reabsorption of sodium chloride.

True

T/F: The main way the kidney regulates potassium ions is to excrete them.

True

T/F: Aldosterone stimulates the reabsorption of sodium while enhancing potassium secretion.

True

T/F: When aldosterone release is inhibited, sodium reabsorption cannot occur beyond the distal convoluted tubule.

True

The regulation of potassium balance ________.

involves aldosterone-induced secretion of potassium

Annie has just eaten a large order of heavily salted french fries, some pickled eggs, and some cheese. How will consuming this much salt affect her physiology?

There will be a temporary increase in blood volume

What hormone reduces blood pressure and blood volume by inhibiting nearly all events that promote vasoconstriction and sodium ion and water retention?

atrial natriuretic peptide

The single most important factor influencing potassium ion secretion is ________.

potassium ion concentration in blood plasma

Which of the choices below exerts primary control over sodium levels in the body?

aldosterone

Atrial natriuretic peptide is a hormone that is made in the atria of the heart. The influence of this hormone is to ________.

reduce blood pressure and blood volume by inhibiting sodium and water retention

T/F: Blood acidity results in depression of the CNS, whereas blood alkalosis results in overexcitement of the CNS.

True

T/F: Prolonged hyperventilation can cause alkalosis.

True

T/F: Respiratory acidosis results when lungs are obstructed and gas exchange is inefficient.

True

T/F: As ventilation increases and more carbon dioxide is removed from the blood, the hydrogen ion concentration of the blood decreases

True

T/F: The phosphate buffer system is relatively unimportant for buffering blood plasma.

True

T/F: Weak acids are able to act as chemical buffering systems for the body because they partially dissociate

True

T/F: The normal pH of blood is 7.35-7.45.

True

T/F: Most acidic substances (hydrogen ions) originate as by-products of cellular metabolism.

True

The maintenance of the proper pH of the body fluids may be the result of ________.

the control of respiratory ventilation

Which of the following is not a chemical buffer system?

nucleic acid

Respiratory acidosis can occur when ________.

a person's breathing is shallow due to obstruction

Problems with fluid, electrolyte, and acid-base balance are particularly common in infants because of their ________.

inefficient kidneys

What is the most abundant intracellular cation?

K+

T/F: Hypoproteinemia reflects a condition of unusually high levels of plasma proteins and causes tissue edema.

False

What is the driving force for water intake?

thirst

Which of the following is not a disorder of water balance?

excessive hydration due to excess ANP secretion

Hypoproteinemia is a condition of unusually low levels of plasma proteins. This problem is often characterized by ________.

tissue edema

The term hypotonic hydration refers to ________.

a condition that may result from renal insufficiency or drinking extraordinary amounts of water

Which of the following conditions promotes edema?
hyponatremia
diabetes mellitus
hypoproteinemia
hemorrhage

hypoproteinemia

What receptors does the brain use to detect changes in osmolality?

osmoreceptors

How much water is generated per day from cellular metabolism?

250 ml

T/F: Atrial natriuretic peptide reduces blood pressure and blood volume by inhibiting nearly all events that promote vasodilation and potassium and water retention.

False

T/F: Aldosterone is secreted in response to low extracellular potassium.

False

Which of the following does NOT impact how much sodium is reabsorbed?

transport maximum of the renal proximal tubule

What is the most important trigger for aldosterone release?

renin-angiotensin-aldosterone mechanism

In order to buffer a strong acid into a weak acid, which has a less dramatic effect on pH, what chemical should be used as the buffer?

weak base

Which of the following creates the greatest osmotic pressure?

H3PO4

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set