Unit 4 Practice Flashcards
What substance increases H+ concentration?
Acids
What substance decreases H+ concentration?
Base
Blood is slightly… at pH 7.35 to 7.45
Alkaline
Blood pH less than 7.35 is…
acidosis; caused by too many hydrogen ions or too little bicarbonate
Blood pH greater than 7.45 is…
alkalosis; caused by too little hydrogen ions or too much bicarbonate
Which three mechanisms regulate acid-base balance?
the buffer system, respiratory system, and renal system
The primary regulator of acid-base balance
Buffers
How do buffers neutralize acids?
buffers act chemically to change strong acids to weak acids or bind acids to neutralize them
Which systems are required for the buffer system to function adequately?
- Nervous System
- Hepatic System
- Respiratory System
- Endocrine System
- Renal System
- Muscular System
respiratory and renal systems must be functioning adequately
RATIONALE: Respiration rate determines the level of CO2 in the blood. Increased respirations lead to increased CO2 elimination, decreasing CO2 in blood. Decreased respirations do the reverse leading to CO2 retention. Kidneys conserve bicarbonate and excrete some acid. Cellular metabolism produces acids (carbonic and metabolic); lungs excrete carbonic acids; kidneys excrete metabolic acids.
How do carbonic acid (H2CO3) and bicarbonate (HCO3-) work on each other?
a strong acid + a strong base are broken down into salt and weak acid
How do the kidneys regulate acid-base balance?
the kidneys conserve bicarbonate and excrete some acid
what are the three mechanisms for acid excretion?
secrete free hydrogen, combine H+ with ammonia (NH3), excrete weak acids
What information can be observed through arterial blood gas (ABG) values?
acid-base statues, underlying cause of imbalance, body’s ability to regulate pH, shows the PaO2 (partial pressure of arterial O2) and O2 saturation
R.O.M.E
Respiratory Opposite:
- Alkalosis: ↑ pH ↓ PaCO2
- Acidosis: ↓ pH ↑ PaCO2
Metabolic Equal:
- Alkalosis: ↓ pH ↓ HCO3−
- Acidosis: ↓ pH ↓ HCO3−
Organs involved in bowel elimination
colon, rectum, anus, peristalsis, sphincter, gastrocolic reflex
Organs involved in urinary elimination
bladder, urethra, internal/external sphincter
What are the functions of the kidney? Mnemonic: “A WET BED”
A: Acid-base balance
W: Water balance
E: Electrolyte balance
T: Toxin removal
B: Blood pressure control
E: Erythropoietin
D: vitamin D metabolism
What are the individual risk factors of impaired fluid and electrolyte imbalance?
All individuals are at risk, regardless of age, race, or socioeconomic status
Who has the GREATEST risk of fluid and electrolyte imbalance?
the very young and very old
What are the FOUR greatest physiological risk factors that are associated with fluid and electrolyte imbalance?
Excessive production or intake of metabolic acid
Altered acid buffering due to loss or gain of bicarbonate
Altered acid excretion
Abnormal shift of H+ into cellsW
Why are the very young at risk of fluid and electrolyte imbalance?
immature kidneys, high metabolic rate, large body surface area (means that body & lungs greater in size than their body mass) , and increased respiratory rate, high % of body weight is water
Why are the very old at risk of fluid and electrolyte imbalance?
impaired renal function, decreased thirst, and impaired ability to conserve water
What are the signs and symptoms of fluid overload (edema)?
weight gain of 1kg or more in 24 hours for an adult, distended neck when upright (vascular fluid overload), and dependent edema (interstitial fluid overload).
What are the signs and symptoms of fluid deficiency (dehydration)?
weight loss of 1kg or more in 24 hours for an adult, rapid thready pulse, postural hypotension, and flat neck veins when supine (vascular fluid underload), skin testing (interstitial fluid underload), and decreased level of consciousness caused by osmotic shift of water OUT of brain cells