1 Flashcards
What may result from excessive vomiting, or the ingestion of alkaline drugs? And, how is it counteracted?
- Metabolic alkalosis
- In addition to chemical buffering, both respiratory and renal compensation are used to counteract these changes in plasma pH
What may result from Severe Diarrhea, Diabetes Mellitus, Strenuous Exercise, or Uremic Acidosis? And, how is it counteracted?
- Metabolic acidosis
- In addition to chemical buffering, both respiratory and renal compensation are used to counteract these changes in plasma pH
What is due to an decreased plasma concentration of carbon dioxide and is caused by hyperventilation? Also, how is it counteracted?
- Respiratory alkalosis
- Renal compensation is used to counteract these changes in plasma pH, in addition to chemical buffering
What is due to an increased plasma concentration of carbon dioxide and is caused by hypoventilation? Also, how is it counteracted?
- Repiratory acidosis
- Renal compensation is used to counteract these changes in plasma pH, in addition to chemical buffering
How do metabolic imbalances occur?
- Result from changes to pH through means not related to Carbon Dioxide concentrations
How do respiratory imbalances occur?
- Result from changes in carbon dioxide concentrations
How are acid imbalances categorized?
- They are categorized as respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis
What would occur if a decrease in pH occurred in renal compensation?
- It will result in an increased secretion of Hydrogen ions, an increased reabsorption of Bicarbonate ion (HCO3–), and an increased synthesis of Bicarbonate ion (HCO3–).
What is the third line of defense against acid-base disturbances and occurs within hours to days? And, how does it work?
- Renal compensation, regulates pH through changes to Hydrogen ion Excretion to Bicarbonate ion (HCO3–) Excretion, and Ammonium (NH₄⁺) Secretion in the Urine.
How is the plasma pH decreased due to respiratory compensation?
- Through decreases in ventilation, resulting in an increase in plasma concentration of carbon dioxide (CO₂), which subsequently increases the plasma concentrations of hydrogen ions, and decreases the plasma pH
How is the plasma pH increased due to respiratory compensation?
- Through increases ventilation, resulting in a decrease in plasma concentration of carbon dioxide (CO₂), which subsequently decreases the plasma concentration of hydrogen ions, and increasing the plasma pH
What is the second line of defense against acid-base disturbances and occurs within minutes? And, how does it work?
- Respiratory compensation, and it regulates pH through changes in ventilation
What are the most important chemical buffers in the ICF?
- Proteins, hemoglobin, and phosphates
What are the most important chemical buffers in the ECF?
- They are the carbonic acid & bicarbonate buffer pair —> H2CO3↔ HCO3– + H+
Describe the chemical buffering mechanism of action
- Upon coming into contact with a chemical buffer system, acids and bases spontaneously undergo the associated reactions
What is the first line of defense against acid-base disturbances and occurs within seconds? And, how does it work?
Chemical buffering, it works by minimizing changes in pH by adding or removing an acid or base from solution.
How is the chemical buffering system different from the renal & respiratory compensation systems?
- Chemical buffering systems are always present, always available, and always being used
- Whereas Respiratory compensation & Renal compensation are feedback loops involving multiple steps and multiple body systems
List the 3 body defense mechanism against acid-base distubances
- Chemical buffering, respiratory compensation, and renal compensation.
What is the pH range that is compatible with life?
- 6.8 to 8.0
What are the consequences if the pH of arterial blood is outside the normal pH range? (7.35 to 7.45)
- There would be changes in the excitablibilty of neurons and muscle cells, changes in protein conformation, and changes in potassium balance.
- Interfering with the normal cell functioning
What is the normal pH of arterial blood? And, how is it regulated?
- The normal pH of arterial blood is between 7.35 to 7.45
- It is regulated through there homeostatic maintenance of hydrogen ions in the arterial blood
What is the pH value of an basic or alkaline solution?
- A pH of more than 7
What is the pH value of an acidic solution?
- A pH of less than 7
How is the acid-base balance achieved?
- It is achieved through the regulation of hydrogen ions (H+) concentrations in body fluids
What are psychosocial factors? And, how do they influence water balance?
- Such as habits or social engagements, which influence water balance, irrespective of thirst or vasopressin secretion
How does the dryness of the oral cavity influence the water balance?
- It stimulates thirst but doesn’t influence vasopressin secretion
What are stressors? And, how do they influence water balance?
- Such as pain, fear, & trauma; that increase vasopressin secretion, but do not influence thirst.
List some of the other regulators influences on water balance
- Stressors, dryness of the oral cavity, & psychosocial factors
What occurs in response to a water deficit in the body?
- Both thirst and vasopressin secretion would be stimulated (water input & output regulators).
- This is achieved through the coordination of the Hypothalamic osmoreceptors, the left Atrial Volume Receptors, and Angiotensin II.
How is water output regulated?
- By regulating the tubular reabsorption of water in the Kidneys, which is mediated by the actions of vasopressin secretions
How is water input regulated?
- By thirst, which is coordinated by the thirst centre of the hypothalamus (hypothalamic osmoreceptors)
How is the water balance regulated?
- It is maintained through the regulation of the water input & output
What is included in the insesible loss of water category ?
- It includes water output from the lungs (through respiration) & from non-sweating skin (through evaporation)
How is the daily water output calculated?
- It occurs through perispiration, fecal & urinary loss, and insensible water loss
How is the daily water input calculated?
- It occurs through ingestion of fluids & food, and also through the metabolic production of water
What are the symptoms and effects of hypotonicity?
- Neuronal changes resulting in altered mental functioning, circulatory disturbances resulting in hypertension, & muscle weakness
What are the symptoms and effects of hypertonicity?
- Neuronal changes resulting in altered mental functioning, circulatory disturbances resulting in hypotension, and anatomic changes resulting in dry skin, sunken eyeballs, & dry tongue
What can result from renal failure, inappropriate levels of vasopressin secretion, or a rapid Ingestion of excessive amounts of water?
- Hypotonicity
What can result from an insufficient water intake, an excessive water loss, or from diabetes mellitus
- Hypertonicity
What are the effects of an hypertonic solution on RBCs?
- The extracellular water concentration is lower than the intracellular water concentration and there is a net movement of water out of the cell causing the cell to shrink.
What are the effects of an hypotonic solution on RBCs?
- The extracellular water concentration is higher than the intracellular water concentration and there is a net movement of water into the cell causing the cell to swell
What are the effects of an isotonic solution on RBCs?
- In an isotonic solution the intracellular and extracellular water concentrations are the same and there is an equal and opposite movement of water across the membrane
What results from an excess of water in the ECF? And provide an example of this situation
- A hypotonic cellular environment,
- Associated with overhydration
What results from a deficit of water in the ECF? And provide an example of this situation
- A hypertonic cellular environment,
- Associated with dehydration
What leads to a change in osmolarity?
- A change in water balance not accompanied by a corresponding change in salt balance
What is the term that refers to a measure of the concentration of an individual solute particles dissolved in a fluid?
- Osmolarity
What happens when the arterial blood pressure experiences a decrease, and how does that effect the renal handling of sodium (Na+)?
- A decrease in BP influces both GFR & the secretion of aldosterone. As a result, Na+ excretion is decreased & Na+ conservation is increased, thus restoring the BP
How is the conservation or excretion of salt regulated ?
-Through regulating GFR & the tubular reabsorption of sodium (Na+)
How is the salt balance regulated?
- Salt balance is only regulated via the kidneys through urinary loss
Define salt output, and how many g/day is it?
- Occurs through perspiration and fecal & urine excretion.
- Feces & loss in sweat = 0.5 g/day & 10.0 g/day is excreted in urine
Total salt output is = 10.5 g/day
Define salt input, and how many g/day is it?
- Salt input occurs only through ingestion
- 10.5 g/day
Why is the maintenance of ECF osmolarity important?
- For the maintenance of an isotonic cellular environment, and is dependent on water balance
Why is the maintenance of ECF volume important?
- For the maintenance of the blood pressure, and it is dependent on the salt balance
How is fluid balance regulated?
- Through the regulation of the ECF volume and osmolarity
What is fluid balance in the body dependent on?
- On water and salt balance
Why do different fluid compartments have different ionic compositions?
- They have different ionic compositions due to the barriers that separate them, such as the blood vessel walls & the plasma membrane of cells
How many litres of bodily fluids does the ICF represent (% as well)?
- 28 litres or 67% of total body fluids
What types of fluids are included in the ECF? And, how many litres of bodily fluids does it represent (% as well)?
- It includes: Plasma, lymph, interstitial fluid, and transcellular fluids
- Accounting for 14 litres or 33% of total body fluid
Where are the fluids in the body located in?
- In the ECF & ICF
What is the term that refers to when the output exceeds input?
- A negative balance
What is the term that refers to when the input exceeds output?
- A positive balance
What is the term that is referred to a substance with equal input and output?
- Stable balance
What does output from the body include?
- It includes metabolic consumption & excretion
What does input into the body include?
- It includes metabolic production & ingestion
