Ch.24 entire review

The atrial and brain natriuretic peptides inhibit the secretion of which of the following?

-ADH -renin

How does blood plasma differ from the intracellular fluid?

-K+ concentration is lower in plasma. -Na+ concentration is higher in plasma. -Ca2+ concentration is higher in plasma.

Which statements are true concerning the protein buffer system?

-Carboxyl groups (-COOH) release H+ and buffer increases in pH. -Amino groups (-NH2) bind H+ and buffer decreases in pH. -The protein buffer system is especially important in the ICF.

Which statements are true regarding fluid sequestration? Select all that apply.

-Causes of fluid sequestration include edema and hemorrhage. -It is a condition in which excess fluid accumulates in a particular location.

Which are true regarding phosphate?

-It can be generated by the hydrolysis of ATP. -It exist in fluids as an equilibrium mixture of phosphate, monohydrogen phosphate and dihydrogen phosphate. -It is a component of nucleic acids, phospholipids, ATP, GTP, and cAMP.

Aldosterone stimulates which of the following?

-Renal reabsorption of sodium -Renal secretion of potassium

How does the phosphate buffer system differ from the bicarbonate buffer system?

-The phosphate buffer system has a higher optimal pH. -Phosphates are more important in the renal tubules and ICF. -The phosphate buffer system has a stronger buffering effect than an equal amount of bicarbonate buffer.

Which are functions of chloride ions?

-They participate in the chloride shift in that accompanies carbon dioxide loading and unloading. -They contribute to formation of stomach acid. -They play a major role in the regulation of body pH. -important in osmotic balance

Which are affected by aldosterone?

-blood volume -BP -urine volume

Which are possible causes of hypokalemia?

-excessive laxatives -heavy sweat, diarrhea, vomit -alkalosis -aldosterone hypersecretion

What are possible consequences of hypernatremia? Select all that apply.

-hypertension -water retention -edema

Which may be caused by acidosis?

-hypochloremia -hypocalcemia -hyperkalemia

Under conditions do nerve and muscle cells become less excitable?

-hypokalemia -slow-onset hyperkalemia

Effects of hypercalcemia are:

-muscle weakness -depressed reflex -cardiac arrhythmia

By which means can water move from one fluid compartment to another?

-osmosis -capillary filtration

Which factors determine the amount of acid or base that can be neutralized by a chemical buffer system?

-pH -concentration of buffer

Which statements are true regarding potassium homeostasis?

-potassium homeostasis is closely linked to sodium -aldosterone stimulates renal secretion of K+

Prolonged, heavy work increases which of the following? Select all that apply.

-respiratory loss -perspiration

Why are electrolytes physiologically important?

-they affect the osmolarity of the body fluids -they are chemically reactive and participate in metabolism -they determine the electrical potential across cell membranes

If the pH of the tubular fluid drops too low, H+ concentration in the fluid is so high that tubular secretion ceases. What is the limiting pH for tubular secretion?

4.5

what is the optimal pH of the phosphate buffer system

6.8

which is the best definition of a weak base?

A base that binds only some of the available H+ and has relatively small effect on pH

What is the complete chemical equation for the bicarbonate buffer system?

CO2 + H2O <-> H2CO3 <-> HCO3- + H+

Increased blood osmolarity stimulates hypothalamic osmoreceptors. This triggers the posterior pituitary to release which of the following?

ADH

Which has the largest effect on plasma sodium concentration?

ADH

Which can cause hypotonic hydration?

ADH hypersecretion

Name the three important chemical buffer systems in the body.

Bicarbonate, phosphate, and protein

The bicarbonate system works quite well because the lungs and kidneys constantly remove which of the following? This prevents equilibrium from being reached.

CO2

What are the primary effects of aldosterone on urine composition?

Decreases NaCl, increases K+, and decreases pH

Which most often results from heavy sweating, chronic vomiting or diarrhea, excessive use of laxatives, aldosterone hypersecretion, or alkalosis?

Hypokalemia

Which may be caused by alkalosis?

Hypokalemia Hyperchloremia Hypocalcemia

What are the percentages of each fluid compartment?

ICF-65% ECF: 35% -interstitial 25% -blood/lymph 8% -transcellular 2%

Parathyroid hormone (PTH) increases excretion of phosphate in order to do which of the following?

Increasing the concentration of free calcium ions in the ECF

Why do people salivate less when they are thirsty?

Lower capillary blood pressure and higher osmolarity of the blood leads to a decrease in saliva production. -Sympathetic output from the hypothalamus inhibits the salivary glands.

Which of the following may cause metabolic alkalosis?

Overuse of intravenous bicarbonate solutions or aldosterone hypersecretion

Which hormone plays a major role in calcium homeostasis?

PTH

Calcium homeostasis is regulated by which hormones?

PTH Calcitonin Calcitriol

cause of metabolic alkalosis

Rare but can result from chronic vomiting; overuse of antacids; aldosterone hypersecretion

Describe renal compensation in response to acidosis.

The renal tubules increase the rate of H+ secretion.

What must be true in order for tubular secretion of hydrogen ions to take place?

There is a concentration gradient between the renal tubule cell and the tubular fluid.

Which best defines fluid sequestration?

a condition in which excess fluid accumulates in a particular location

Estrogen causes women to retain salt and water during pregnancy by mimicking the effects of which other steroid hormone?

aldosterone

In response to ADH release, collecting duct cells in the kidneys increase their expression of which of the following?

aquaporins

The renal tubules are incapable of reabsorbing HCO3- directly. Instead, an enzyme breaks down the H2CO3 in the tubular fluid to form CO2, which can be reabsorbed. What is the name of the enzyme?

carbonic anhydrase

Any substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration falls is classified as a ______ buffer. Examples include proteins, bicarbonate, and phosphate.

chemical

Which type of buffer is defined as a substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration falls?

chemical

Which ions are the most abundant anions of the ECF?

chloride

Which are possible effects of fluid deficiency?

circulatory shock and neurological dysfunction

What is the primary effect of chloride imbalances?

disturbances in acid-base balance

Water balance is most directly tied to which of the following?

electrolyte balance

Which term is used to refer to the ions that participate in important metabolic and physiological processes?

electrolytes

Blood plasma is a type of ______ fluid.

extracellular

True or false: Dehydration affects the extracellular fluid exclusively.

false

True or false: During dehydration, the kidneys restore blood volume by the formation of metabolic water.

false

True or false: Respiratory loss decreases in cold weather.

false, it increases b/c of dry air absorbing more body water

Most of the body's magnesium is lost in which of the following?

feces

Edema is the most common form of which of the following?

fluid sequestration

What might happen if you lost large volumes of water and salt and then drank large quantities of plain water?

hypotonic hydration (water intoxication)

cause of respiratory acidosis

hypoventilation

______ may be caused by diabetes mellitus, hyperkalemia; chronic diarrhea and excessive alcohol consumption

metabolic acidosis

Even though aldosterone ______ the tubular reabsorption of sodium and water, this is offset by a(n) ______ in GFR; thus there is only a small ______ in urine output.

increases; increase; decrease

Which best describes the role of the kidneys in maintaining water balance during dehydration?

kidneys can slow down the rate of water and electrolyte loss through changes in urine volume and composition

Fluid deficiency can cause serious effects. For example, circulatory shock may be caused by which of the following?

loss of blood volume

Which is a common effect of hypokalemia?

loss of muscle tone

______ acidosis can result from increased production of organic acids, such as lactic acid in anaerobic fermentation and ketone bodies in alcoholism and diabetes mellitus.

metabolic

______ is rare and may be caused by chronic vomiting; overuse of antacids and aldosterone hypersecretion.

metabolic alkalosis

Which term refers to water formed by dehydration synthesis and aerobic respiration?

metabolic water

Which inhibits Na+ and water reabsorption and lowers the blood pressure?

natriuretic peptides

Why can the kidneys neutralize more acid or base than any other buffer in the human body?

only the kidneys actually expel H+ from the body

Which is the same in the ICF and in the blood plasma?

osmolarity

How does water move from the digestive tract to the bloodstream?

osmosis

If the osmolarity of the tissue fluid rises, water moves ______ the cells.

out of

obligatory water loss

output that is relatively unavoidable; expired air, cutaneous transpiration, sweat, fecal moisture, and minimum urine output

The ______ buffer system is a solution of H(PO4)2 and H2(PO4).

phosphate

A ______ buffer is a system (for example the respiratory or urinary system) that stabilizes pH by controlling the body's output of acids, bases, or CO2.

physiological

hypercalcemia

plasma concentrations of calcium greater than 5.8 mEq/L? Multiple choice question.

what is the most dangerous electrolyte imblanace

potassium imbalances

Glucocorticoids

promotes sodium reabsorption and edema

The pH of intracellular fluid is buffered mainly by which of the following?

proteins

Which are possible complications of volume excess and hypotonic hydration?

pulmonary and cerebral edema

dehydration _______ blood osmolarity

raises

Fluid intake is governed mainly by thirst. Which of the following can make a person thirsty?

reduced BP

dehydration _______ blood volume

reduces

Progesterone

reduces sodium reabsorption and has a diuretic effect

Which occurs when blood volume and pressure are too high?

release of ADH is inhibited

The bicarbonate buffer system would not work very well in the human body if not for the action of the lungs and the kidneys doing which of the following?

removing CO2 produced by the buffer system

Which results when CO2 is eliminated faster than it is produced (for example, during hyperventilation)?

repspiratory alkalosis

______ acidosis occurs in hypoventilation, when carbon dioxide accumulates in the ECF and lowers its pH.

respiratory

Which two organ systems form physiological buffers that help stabilize pH by controlling the body's output of acids, bases, or CO2? Select two options from the list below.

respiratory and urinary systems

During dehydration, urine volume decreases and more body water is retained. This is often due to increased reabsorption of which of the following?

sodium

Changes in urine volume are often linked to adjustments in which of the following?

sodium reabsorption

When a person is thirsty, the osmoreceptor response leads to ______ output from the hypothalamus that inhibits salivation.

sympathetic

True or false: Simply moistening the mouth can temporarily inhibit thirst even if no water reaches the stomach.

true

True or false: The ability of a buffer to function effectively (neutralize acids or bases) depends on the pH of the solution and the concentration of the buffer.

true

True or false: The kidneys cannot compensate very well for inadequate fluid intake, but they compensate very well, on the other hand, for abnormally high fluid intake.

true

True or false: The primary effects of chloride imbalances are disturbances in acid-base balance, but acid-base imbalances can cause chloride imbalances as well.

true

Most water is lost daily through ______.

urine

The intestinal absorption of magnesium is mainly regulated by

vitamin D

If the body has retained too much sodium and water, but the ECF remains isotonic, the person has which of the following?

volume excess

Which can result from aldosterone hypersecretion or renal failure?

volume excess

Sodium is actively pumped across membranes. What compounds passively follow it?

water and chloride

Which best defines preformed water?

water ingested in food and drink

sensible water loss

water loss that is noticed by a person, such as through urine output and visible sweating

Which of the following best defines cutaneous transpiration?

water loss through skin

insensible water loss

water loss we are not conscious of

cutaneous transpiration

water that diffuses through the epidermis and evaporates

The most important buffer system in the blood is the bicarbonate buffer, which is a solution of ______ acid and bicarbonate ions.

weak

In the bicarbonate buffer system, H2CO3- acts as a ______ by releasing H+ and lowering pH, while HCO3- acts as a ______ by binding H+, removing the ions from solution, and raising pH.

weak acid, weak base