APHY 201 Module 12 Fluid and Acid-Base Balance Ivy Tech

The most abundant cation in extracellular fluid is potassium.

False

antidiuretic hormone (ADH)

Increases the permeability of the DCT and collecting duct to water by causing insertion of aquaporins; released by posterior pituitary gland

Where is most water found in the body?

cells

The fluid in the body forms approximately ______ of the body weight in an adult male.

60%

What does over-hydration create in the ECF?

hypotonicity

​The task of eliminating H+ derived from sulfuric, phosphoric, lactic, and other acids rests with the __________.

kidneys

Electrolytes are chemical compounds that dissociate in water to form charged particles called ______.

ions

renin

secreted by juxtaglomerular cells of kidney if BP drops dramatically or low NaCl

Which of the following is NOT an electrolyte?

sugar

​The quantity of any particular substance in the ECF is a readily available internal pool.

true

When a strong base reacts with the bicarbonate buffer system, ______ is formed from the base

water

urine is about 95% ___

water

osmosis

water is reabsorbed into the interstitial fluid by moving through aquaporins in a process known as ________

What is the main clinical effect of systemic alkalosis?

"pins-and needles" sensation in muscle​

water conservation

(ADH) increases reabsorption of water from the renal tubule and decreases urine volume when body water level is low; countercurrent mechanism established by the nephron loop is utilized by the collecting ducts

Which factor accounts for the ability of the body to conserve high levels of sodium?

Aldosterone - it is the hormone from the adrenal gland which causes the kidneys to reabsorb sodium on demand.

The main factor that causes the kidney to conserve water is _____.

Antidiuretic hormone - increases the permeability and absorption of water at the distal convoluted tubules and collecting ducts.

obligatory water reabsorption

Aquaporins always present in PCT to enhance osmosis

facultative water reabsorption

Aquaporins inserted in collecting ducts only if ADH present

A change in pH that has a respiratory cause is associated with an abnormal concentration of:

CO2

loss of base (drop in pH)

Decreased reabsorption of filtered bicarbonate would lead to?

nephron loop

Descending limb - H2O is reabsorbed but solutes are not causing filtrate to be concentrated. Ascending limb - H2O cannot leave; solutes can. Responsible for creating countercurrent mechanism.

metabolic alkalosis

Disorder indicated by a rising blood pH and a rising plasma bicarbonate

metabolic acidosis

Disorder indicated by falling blood pH and a falling plasma bicarbonate

respiratory acidosis

Disorder indicated by falling blood pH and a rising partial pressure of carbon dioxide.

respiratory aklalosis

Disorder indicated by rising blood pH and a falling partial pressure of carbon dioxide (hyperventilation)

What are the two factors that are regulated to maintain fluid balance in the body?

ECF volume and ECF osmolarity

Most fluid in the body is in the extracellular fluid (ECF) compartment.

False

gain of base (rise of pH)

Formation of new bicarbonate would lead to?

What is the most important ion, which affects all of the functions of the others?

H+

angiotensin II

In the lungs, angiotensin-converting enzyme (ACE) converts angiotensin I into ___________

__________ fluid lies in the spaces between cells and makes exchanges with the cells, and it represents four-fifths of the ECF compartment.

Interstitial

__________ alkalosis is a reduction in plasma [H+] caused by a relative deficiency of non-carbonic acids.

Metabolic (non-respiratory)

The only cation exerting significant osmotic pressure in the ECF is __________.

Na+

losing acid (H+) and gaining base (HCO3-)

Renal compensation for respiratory acidosis would require the kidneys adjust pH by?

angiotensin I

Renin converts angiotensinogen, a blood protein made by the liver, into _________

proximal convoluted tubule

Site of most reabsorption All nutrients, e.g., glucose and amino acids 65% of Na+ and water, many ions

Which solute plays the biggest role in water reabsorption?

Sodium ions

What describes the response of the kidneys when blood volume falls or blood flow to the kidneys decreases?

The kidneys secrete renin, which helps activate the hormone angiotensin II. Angiotensin vasoconstricts blood vessels as well as stimulates the secretion of aldosterone and ADH to increase sodium and water retention in the kidneys.

Antidiuretic hormone-controlled H2O reabsorption is of primary importance in regulating ECF osmolarity.

True

dilute urine and a reduced volume of body fluids

When ADH levels are low, the lack of aquaporins in the DCT and collecting ducts will cause?

distal convoluted tubule and collecting duct

Where does aldosterone and ADH exert effects?

sodium; potassium

__________ is abundant in ECF, and __________ is abundant in ICF

false

a decrease in extracellular fluid solute concentration (hypotonic solution) causes water to leave the cells

aldosterone

a hormone produced by the adrenal gland to act in the DCT and collecting ducts to aid in the conservation of sodium and secretion of potassium due to insertion of Na+/K+ pumps. This will promote water retention and increase blood volume and blood pressure.

antidiuretic hormone (ADH)

a hormone produced by the posterior pituitary causes the permeability of the distal tubule and collection ducts to water to increase due to insertion of aquaporins, and thus promotes the conservation of water.

A major stimulus for the release of antidiuretic hormone is __________.

a rise in plasma osmolality

chemical buffer

a system of one of more compounds that resist changes in pH when a strong acid or base is added. They do this by binding H+ when the pH drops (becomes acidic) and releasing H+ when the pH rises (becomes basic/alkaline)

parathyroid hormone

acts on the ascending nephron loop, distal tubule, and collecting tubule to increase Ca2+ reabsorption and blocks HPO42- reabsorption

The main reason for the wide range in body H2O among individuals is their variable amount of:

adipose tissue

When the concentration of Na+ in the ECF decreases, __________.

aldosterone levels increase

increase

an _____________ in extracellular fluid solute concentration (hypertonic solution) causes water to shift out of the cells

solute concentration

anything that changes ______________ in any compartment leads to net water flows

true

because water moves freely between compartments, the solute concentrations of all body fluids are equal (except during the first few minutes after the change occurs in one of the fluids until it equilibrates)

When an acid reacts with the bicarbonate buffer system, ______ is formed as an end product.

bicarbonate

In the bicarbonate buffer system, _____ reacts with bases

carbonic acid

In the bicarbonate buffer system, _____ reacts with bases.

carbonic acid

electrolytes

chemical compounds that dissociate into ion in water. They can conduct an electric current. Examples: inorganic and organic acids and bases, inorganic salts, and some proteins

Which is the most abundant extracellular ion?

chloride

intracellular fluid compartment

collectively all of the fluid inside of cells; K+ is most abundant solute

extracellular fluid compartment

composed of two subcompartments: plasma, the fluid portion of blood and interstitial fluid, the fluid between tissue cell. Na+ is most abundant solute

thirst mechanism

driving force for water intake; governed by hypothalamus

ANP functions

decrease sodium reabsorption in the DCT; vasodilation of afferent arteriole to increase GFR; inhibiting ADH release from posterior pitiuitary; decreasing blood volume and blood pressure

When atrial natriuretic peptide is released by the heart because of increased blood pressure, it causes __________.

decreased sodium and water reabsorption

countercurrent mechanism

establish and maintain osmotic gradient (300 mOsm to 1200 mOsm) from renal cortex through medulla due to nephron loop saving water on descending loop and saving solutes on ascending loop. Allows kidneys to vary urine concentration.

true

extracellular fluid solute concentration determines intracellular fluid volume

osmotic gradient

formed by nephron loop and utilized by collecting ducts to conserve water when ADH is present

Acidosis results in increasing levels of what ion?

hydrogen

What is the main force that causes fluid to leave the plasma compartment?

hydrostatic pressure

The two principal body fluid compartments are:

intra and extra cellular

The symptoms of dehydration result from loss of _____ water.

intracellular

What are the most plentiful buffers of the body fluids?

intracellular and plasma proteins

Which of the following is an effect of acidosis?

mental confusion

distal convoluted tubule and collecting ducts

only modify filtrate if hormones are present (aldosterone, ADH, atrial natriuretic peptide, or parathyroid hormone)

The __________ of a fluid is a measure of the concentration of the individual solute particles dissolved in it.

osmolarity

if overhydrated

osmolarity of body fluids is low so ADH is not released and water remains to form a large amount of dilute urine; countercurrent mechanism established by the nephron loop is NOT utilized by the collecting ducts

What is the main force that causes water to move among the various fluid compartments?

osmosis

As total body water decreases, the _____ of the extracellular fluid increases.

osmotic pressure

ADH is secreted from the _____.

posterior pituitary

The most important buffer system in the intracellular fluid compartment (ICF) is the __________ buffer system.

protein

Hydrogen ions are secreted into the filtrate mainly by the __________ .

proximal convoluted tubule

Juxtaglomerular apparatus

regulates GFR and controls systemic blood pressure; consists of a portion of the DCT and a portion of the afferent arteriole of the same nephron; controls the filtering function of the glomerulus by changing the diameter of afferent or the efferent arterioles; cells produce renin when blood pressure is low

atrial natriuretic peptide (ANP)

released by cells in atrium of the heart when blood pressure is high to cause sodium to be lost in the urine

ANP promotes which of the following?

sodium excretion

Which of the following does not play a significant role in maintaining acid-base balance?

stomach

tubular secretion

the process by which certain substances are transported from plasma to the tubular fluid; removes various organic compounds, hydrogen ions to maintain acid-base balance; occurs mostly in the PCT

A chemical buffer system is a mixture in a solution of two chemical compounds that minimize pH changes when either an acid or a base is added to or removed from the solution.

true

angiotensin II functions

vasoconstrict blood vessels, stimulate release of aldosterone from adrenal cortex, stimulate hypothalamus to produce thirst, stimulate release of antidiuretic hormone from posterior pituitary