Podcast
Questions and Answers
What is the main consequence of hypernatremia on cellular tonicity?
What is the main consequence of hypernatremia on cellular tonicity?
Which process causes oliguria in dehydration?
Which process causes oliguria in dehydration?
What are the signs and symptoms of dehydration?
What are the signs and symptoms of dehydration?
How does edema differ from cellular swelling?
How does edema differ from cellular swelling?
Signup and view all the answers
What is the primary function of salts in the body?
What is the primary function of salts in the body?
Signup and view all the answers
What condition can result from hyponatremia due to low aldosterone levels?
What condition can result from hyponatremia due to low aldosterone levels?
Signup and view all the answers
Which fluid compartment makes up approximately 2/3 of the total body fluid?
Which fluid compartment makes up approximately 2/3 of the total body fluid?
Signup and view all the answers
What is the major cation found in the extracellular fluid (ECF)?
What is the major cation found in the extracellular fluid (ECF)?
Signup and view all the answers
Which type of solutes do not dissociate in water?
Which type of solutes do not dissociate in water?
Signup and view all the answers
What is the main function of electrolytes in the body?
What is the main function of electrolytes in the body?
Signup and view all the answers
Which component of the body has a decline in water content to approximately 45% during old age?
Which component of the body has a decline in water content to approximately 45% during old age?
Signup and view all the answers
What causes a net water flow when there is a change in solute concentration of any compartment within the body?
What causes a net water flow when there is a change in solute concentration of any compartment within the body?
Signup and view all the answers
What is the most common cause of hypokalemia?
What is the most common cause of hypokalemia?
Signup and view all the answers
Which hormone plays the biggest role in the regulation of sodium by the kidneys?
Which hormone plays the biggest role in the regulation of sodium by the kidneys?
Signup and view all the answers
What is the main trigger for aldosterone release in the body?
What is the main trigger for aldosterone release in the body?
Signup and view all the answers
What is the primary function of parathyroid hormone (PTH) in calcium regulation?
What is the primary function of parathyroid hormone (PTH) in calcium regulation?
Signup and view all the answers
What happens to neuromuscular excitability in the presence of hypercalcemia?
What happens to neuromuscular excitability in the presence of hypercalcemia?
Signup and view all the answers
What are the common causes of metabolic acidosis?
What are the common causes of metabolic acidosis?
Signup and view all the answers
In which scenario will the respiratory system decrease respiration?
In which scenario will the respiratory system decrease respiration?
Signup and view all the answers
What is the primary disturbance in respiratory acidosis?
What is the primary disturbance in respiratory acidosis?
Signup and view all the answers
What is the effect of blood pH below 6.8?
What is the effect of blood pH below 6.8?
Signup and view all the answers
What compensation mechanism does the kidneys employ in response to respiratory alkalosis?
What compensation mechanism does the kidneys employ in response to respiratory alkalosis?
Signup and view all the answers
Study Notes
Water Balance and Intake
- Water intake must equal water output, approximately 2500 ml/day
- Water intake comes from ingestion and metabolism (Krebs cycle and electron transport chain)
- Water output includes urine (60%), insensible water loss (through skin and lungs), perspiration (sensible), and feces
Disorders of Water Balance
- Dehydration: ECF water loss due to various causes (hemorrhage, severe burns, prolonged vomiting or diarrhea, profuse sweating, water deprivation, diuretic abuse, endocrine disturbances)
- Signs and symptoms of dehydration: "cottony" oral mucosa, thirst, dry flushed skin, oliguria (reduced or low urine output)
- Oliguria may lead to weight loss, fever, mental confusion, hypovolemic shock, and loss of electrolytes
Edema
- Atypical accumulation of interstitial fluid, resulting in tissue swelling (not cell swelling)
- May impair tissue function by increasing distance for diffusion of oxygen and nutrients from blood into cells
- Can be caused by increased fluid flow out of blood (hydrostatic) or decreased return of fluid (osmotic) to blood
Electrolyte Balance
- Electrolyte balance usually refers to salt balance
- Salts control fluid movements, provide minerals for excitability, secretory activity, and other functions
- Salts enter the body through ingestion and metabolism
- Salts are lost via perspiration, feces, urine, and vomit
Regulation of Sodium Balance
- Hyponatremia: Decreased sodium decreases ECF osmolarity
- Causes of hyponatremia: Renal failure, Vomiting & Diarrhea, Diuretic use, Excessive fluids, Low Aldosterone
- Hyponatremia can lead to cellular edema (especially in the brain)
Body Water Content
- Infants: 73% or more water (low body fat, low bone mass)
- Adult males: ~60% water
- Adult females: ~50% water (higher fat content, less skeletal muscle mass)
- Adipose tissue is the least hydrated of all
- Water content declines to ~45% in old age
Body Fluid Compartments
- Two main fluid compartments: Intracellular fluid (ICF) and Extracellular fluid (ECF)
- ICF: fluid inside cells (2/3 of total body fluid)
- ECF: fluid outside cells (1/3 of total body fluid)
- Plasma (Intravascular), Interstitial fluid (IF), Lymph, CSF, Eye humor (fluids), synovial fluid, serous fluid, and gastrointestinal secretions
Composition of Body Fluids
- Water is the universal solvent
- Solutes are classified as non-electrolytes and electrolytes
- Non-electrolytes: most are organic molecules that do not dissociate in water (e.g., glucose, proteins, amino acids, lipids, creatinine, and urea)
- Electrolytes: dissociate into ions in water, have greater osmotic power than non-electrolytes (e.g., inorganic salts, all acids and bases, some proteins)
Electrolytes and Osmosis
- Electrolytes conduct electrical current
- Water moves to the area with greater solute (electrolyte) concentration
- ECF vs ICF: each fluid compartment has a distinctive pattern of electrolytes
- ECF: electrolyte contents mostly similar, major cation: sodium (Na+), major anion: chloride (Cl-)
- ICF: contains more soluble proteins than plasma, major cation: potassium (K+), major anion: Hydrogen Phosphate (HPO42-)
Regulation of Sodium Balance
- Na+-water balance is linked to blood pressure and blood volume control mechanisms
- Changes in blood pressure or volume trigger neural and hormonal controls to regulate Na+ content
- Aldosterone plays the biggest role in regulating Na+ by the kidneys, causing Na reabsorption
Hypokalemia and Hyperkalemia
- Hypokalemia: Low potassium levels, affects cardiovascular/neuromuscular resting membrane potentials
- Causes of hypokalemia: fluid loss due to vomiting, diarrhea, prolonged diuretic use (most common)
- Hyperkalemia: Excessively high potassium levels, renal failure, tissue destruction (burns, trauma, & flesh-eating bacteria)
Calcium and Phosphate Regulation
- Calcium balance is controlled by parathyroid hormone (PTH) and rarely deviates from normal limits
- PTH promotes an increase in blood calcium levels by targeting the small intestine, kidneys, and bones
- Calcium is important for blood clotting, cell membrane permeability, and neuromuscular excitability
Acid-Base Balance
- pH affects all functional proteins and biochemical reactions, so it is closely regulated by the body
- Normal pH of body fluids: 7.35-7.45
- Alkalosis: arterial pH >7.45, acidosis: arterial pH <7.35
- Respiratory acidosis: due to decreased ventilation or gas exchange, CO2 accumulates in blood, and blood pH drops
- Respiratory alkalosis: due to hyperventilation, often resulting from stress or pain, CO2 is eliminated faster than produced, and blood pH increases
Metabolic Acidosis and Alkalosis
- Most important indicator of metabolic function is HCO3-
- Normal HCO3-: 22-26 mmol/L
- HCO3- < 22 mmol/L: Metabolic acidosis, causes: 3-ketoacidosis from diabetes or renal failure, excessive alcohol consumption, lactic acid accumulation, diarrhea, and HCO3- loss
- HCO3- > 26 mmol/L: Metabolic alkalosis, less common, causes: excessive vomiting, excessive antacid use
Effects of Acidosis and Alkalosis
- Blood pH below 6.8 causes CNS depression, may lead to coma and death
- Blood pH above 7.8 causes overexcitation of the nervous system, leading to muscle tetany, extreme nervousness, convulsions, and death, often from respiratory arrest
pH Compensation Mechanisms
- If acid-base imbalance is due to malfunction of one physiological buffer system, the other system tries to compensate
- Respiratory system attempts to correct metabolic acid-base imbalances by increasing or decreasing respiration
- Kidneys attempt to correct respiratory acid-base imbalances by increasing or decreasing bicarbonate reabsorption/acid secretion
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on body water content, body fluid compartments, and electrolytes as covered in Chapter 26 of BIOL-244 Human Anatomy & Physiology by Dr. David Roberts. Learn about the variations in water content between infants, adult males, and adult females, as well as the different fluid compartments in the body.
