chapter 27 assessment

What roles does phosphate play in the body?

It affects neuromuscular activity. It affects the action of the sodium-potassium pump.

Which of these substances plays a major role in regulating potassium ions?

aldosterone

A force that causes the movement of fluid out of the capillary is

blood pressure

The respiratory system influences the acid-base balance by utilizing the

carbonic acid/bicarbonate buffer system.

The reaction between carbon dioxide and water to produce carbonic acid is catalyzed by

carbonic anhydrase.

Under normal conditions, most water loss from the body is through the

kidneys

The main regulator of serum phosphate levels is a transport process in the

kidneys.

Which of the following represents the largest fluid compartment?

intracellular fluid

Body fluid pH will rise dramatically whe

large amounts of bicarbonate are ingested.

The distribution of sodium and potassium ions between intracellular and extracellular compartments is

potassium mainly intracellular; sodium mainly in extracellular.

buffers function to ________________.

prevent dramatic changes in pH

In which of these compartments would fluid accumulate in edema?

tissue

Check all that occur as a result of high blood pressure and high blood volume.

ADH secretion increases

check all that occur as a result of low blood volume and low pressure

ADH secretion increases Juxtaglomerular cells increase renin secretion Afferent arterioles in the kidneys constrict

What hormone regulates potassium levels, and how does it work?

Aldosterone; increases secretion of potassium

buffers

All of these are correct statements.

Which of the following are sources of water intake?

Cellular metabolism Ingestion

Which of these is correct concerning sodium ion regulation?

Increased blood pressure causes a reduction in ADH secretion.

Name the ion that commonly serves as a cofactor for intracellular enzymes, such as the sodium-potassium pump.

Magnesium

In response to decreased free magnesium ion (Mg2+) concentration in the extracellular fluid, which of the following occurs?

Mg2+ is reabsorbed at a faster rate in the nephrons

_____ is the most significant solute in determining the distribution of water among fluid compartments.

Na+

Which of the following is NOT a buffer system of the body?

NaCl buffer system

What cell structure regulates the composition of the intracellular fluid?

Plasma membrane

The predominant intracellular cation is

Potassium

Which of the following is not a function of the carbonic acid/bicarbonate system?

Regulation of the pH of the intracellular environment

Hyperventilation of the lungs can lead to ______________________.

Respiratory acidosis

Check all that would occur to intracellular and extracellular fluid if you become dehydrated.

Solute concentration in the extracellular fluid decreases as a result of dehydration Water moves into the cell from the extracellular fluid

Check all that occur in the kidneys in response to increased body pH levels.

The rate of HCO3- reabsorption from the tubules decreases. The rate of H+ secretion into the filtrate decreases.

When blood pH decreases, which of the following occurs to correct the imbalance?

The respiratory center increases the breathing rate. Correct

Which of the following statements concerning potassium ions is false?

When aldosterone levels are high, potassium secretion is low.

Edema can occur when there is

a blockage of the lymphatics.

Wetting the oral mucosa and stretching the digestive tract will cause ____________ in thirst sensations.

a temporary interruption

Which of the following substances releases hydrogen ions into a solution?

acids

Adequate calcium absorption from the GI tract depends on

adequate amounts of vitamin D.

In order to increase blood pH, which of the following occurs?

all of these choices are correct

Ion levels in the extracellular fluid are adjusted by which of the following?

all of these items are correct

Which of the following can play a role in buffering the pH of urine?

ammonia, bicarbonate ions and phosphate ions

Chloride ions

are regulated with Na+

a weak base

binds little H+ and has a weak effect on pH.

Chemicals that function to minimize changes in the pH of body fluids are called

buffers

Sodium homeostasis leads to the homeostasis of ________________.

chloride

Check all that are major anions in the body.

chloride and bicarbonate

What is the main role of magnesium ions in the body?

cofactors for intracellular enzymes

Synovial fluid is a part of which of the following fluid compartments?

extracellular

Slight deviations from the normal concentration of ___________ ions can shut down metabolic pathways as well as alter the structure and function of other macromolecules.

hydrogen

Oversecretion of aldosterone causes

hypernatremia.

Decreased extracellular potassium levels cause

hyperpolarization of cell membranes.

Loss of a large volume of sweat will

increase the osmolality of body fluids.

An increase in blood CO2 levels is followed by a(n) ____ in H+ ions and a(n) ____ in blood pH.

increase, decrease

An increase in the osmolarity of the extracellular fluid will trigger a(n) ___________ in the secretion of ADH and a(n) ____________ in thirst.

increase, increase

Increased ADH secretion could be stimulated by which of the following situations?

increased blood osmolality

Increased ADH causes a(n) ___________ sensation for thirst, and a(n) ___________ in permeability of the distal convoluted tubule and collecting duct to water, resulting in __________ urine volume.

increased; increased; decreased

Excretion of phosphate

increases free calcium ions in the ECF.

Increased osmolality of the ECF

increases thirst.

If dehydration develops, solute concentration in the extracellular fluid ___________, causing water to move ____________ the intracellular fluid and ___________ the extracellular fluid.

increases, out of, into

The kidneys control pH by

increasing or decreasing the number of bicarbonate ions reabsorbed from the urine.

Edema results when the amount of ___________ fluid increases

interstitial

What organ(s) play(s) a role in the excretion of sodium?

lungs, liver

Parathyroid hormone increases the activity of ___________ cells in bone and increases the rate of calcium ___________ in the kidney tubules.

osteoclast; reabsorption

Calcium balance is influenced by

parathyroid hormone and vitamin D levels.

Which of the following fluid compartments contains the smallest volume of water?

plasma

The most abundant cation in the extracellular fluid is _________________.

sodium

Check all that are major cations in the body.

sodium and potassium

The sensation of thirst results from

stimulation of osmoreceptor cells in the hypothalamus.

Concerning body fluid compartments,

the major influence controlling the movement of water between intracellular and extracellular spaces is osmotic pressure.

Check all that occur as a result of low blood volume and low blood pressure.

urine production increases