Ch 26 Acid/Base

Question 1

2/3 of all fluids reside inside the cell

Answer 1

Intracellular fluid

Question 2

Intracellular fluids major cation is

Answer 2

K+

Question 3

Intracellular fluids major anion is

Answer 3

low Na+, low Cl

Question 4

1/3 of all body fluids reside outside the cell. includes the subcompartments: plasma and intersitial fluid

Answer 4

Extracellular fluid

Question 5

Extracellular fluids major cation is

Answer 5

Na+

Question 6

Extracellular fluids major anion is

Answer 6

Cl-

Question 7

Water serves as the _____ _____ in which a variety of solutes are dissolved

Answer 7

Universal solvent

Question 8

Solutes may be classified broadly as:

Answer 8

electrolytes and nonelectrolytes

Question 9

Have bonds (usually covalent) the prevent them fom dissociating in solution. They are usually organic molecules - glucose, lipds, creatinine, and urea, for example

Answer 9

Nonelectrolytes

Question 10

Chemical compounds that DO dissociate into ions in water. Because ions are charged particles, they can conduct an electrical current. Includes inorganic salts, both inorganic and organic acids and bases, and some proteins

Answer 10

Electrolytes

Question 11

Electrolytes have much (lesser/greater) osmotic power than nonelectrolytes because each electrolyte molecule dissociates into at least 2 ions

Answer 11

Greater

Question 12

Water moves according to osmotic gradients - from an area of (lesser/greater) osmality to an area of (lesser/greater) osmality

Answer 12

Lesser, greater

Question 13

Exchanges between plama and interstitial fluid (IF) occur across

Answer 13

Capillary walls

Question 14

Exchanges between the IF and intracellular fluid (ICF) occur across

Answer 14

Plasma membranes

Question 15

ICF and ECF volumes are always changing because all the nutrients are being absorbed by blood. However, osmolalities remain _____

Answer 15

Equal

Question 16

Increasing the ECF solute causes osmotic and volume changes in the ICF. Conversely, decreasing ECF osmolality causes water to move into the cells. THUS:

Answer 16

ECF solute concentration (osmolality) determines ICF volume (H2O)

Osmolality ↑, H2O ↓

Osmolality ↓, H2O ↑

Question 17

The amount of water reabsorbed in the renal collecting ducts is proportional to

Answer 17

ADH release

Question 18

When ADH levels are low, water reaching the collecting ducts is not reabsorbed and simply flows through resulting in

Answer 18

Dilute urine and a reduced volume of body fluids

Question 19

When ADH levels are high nearly all filtered water is reabosrbed resulting in

Answer 19

A small volume of concentrated urine is excreted

Question 20

_____ of the hypothalamus sense the ECF solute concentration and trigger or inhibit ADH release from the posterior pituitary accordingly

Answer 20

Osmoreceptors

Question 21

Large changes in blood volume or blood pressure also influence secretion of this

Answer 21

ADH

Question 22

A (decrease/increase) in blood pressure increases ADH release both directly via baroreceptors and indirectly via the renin-angiotensin-aldosterone mechanism

Answer 22

Decrease

Question 23

Na is (always/never) secreted from blood to filtrate

Answer 23

Never

Question 24

H₂O (always/never) follows sodium

Answer 24

Always

Question 25

_____ affects all functional proteins and biochemical reactions

Answer 25

pH

Question 26

Normal pH of body fluids

Answer 26

Arterial blood: pH 7.4

Venous blood & IF fluid: pH 7.35

ICF: pH 7.0

Question 27

Less than pH 7

Answer 27

Acidic

Question 28

Greater than pH 7

Answer 28

Basic

Question 29

Alkalosis or alkalemia

Answer 29

arterial pH > 7.45

Question 30

Acidosis or acidemia

Answer 30

arterial pH < 7.35

Question 31

Most H⁺ is produced by

Answer 31

metabolism

Question 32

Concentration of hydrogen ions regulated sequentially by:

Answer 32

1- Chemical buffer systems: rapid, first line of defense

2- Brain stem respiratory centers: 1-3 min

3- Renal mechanisms: most potent, but requires hours to days to effect pH changes

Question 33

Acid & Base acceptor and changes it to its own pH

Answer 33

Buffer

Question 34

Chemical buffer systems:

Answer 34

1- Bicarbonate buffer system

2- Phosphate buffer system

3- Protein buffer system

Question 35

Bicarbonate buffer in the blood

Answer 35

H₂O + CO₂ ==> H₂CO₃ (carbonic acid)

H₂CO₃ ==> H⁺ + HCO₃ (carbonate)

H₂O + CO₂ ⇔ H₂CO₃ ⇔ H⁺ + HCO₃

Question 36

Bicarbonate buffer scenario:

↑ CO2 → More acidic (H+)

what does the body do to fix this?

Answer 36

Body ↑ HCO3 (carbonate) which combines w/ H+ to form H2CO3

Question 37

Bicarbonate buffer scenario:

↑ HCO3 → more basic

What does the body do to fix this?

Answer 37

Body ↑ H+ which combines w/ HCO3 to form H2CO3

Question 38

Hormone steroids:

Answer 38

Estrogen, Progesterone, and Glucocorticoids

Question 39

↑ NaCl reabsorption (like aldosterone), retains H₂O

Answer 39

Estrogen

Question 40

Blocks aldosterone

Answer 40

Progesterone - pregnancy hormone

Question 41

Releases aldosterone

Answer 41

Glucocorticoids (Z.G.)

Question 42

If bp ↑, this inhibits SNS stimulation and dilates the afferent artery ==> ↑ GFR

Answer 42

Baroreceptors

Question 43

P_CO2 below 35 mm Hg

Answer 43

Respiratory alkalosis

• Common result of hyperventilation dues to stress/pain
• CO2 is being eliminated faster than produced

Question 44

Low blood pH and HCO₃

Answer 44

Metabolic acidosis

-Ingestion of too much alcohol

Question 45

Blood pH below 6.8 → depression of CNS → coma →…

Answer 45

Death

Question 46

Blood pH above 7.8 → excitation of nervous system → …

Answer 46

Muscle tetany, extreme nervousness, convulsions, death often from respiratory arrest