Water pH and bufffer
42 Questions
6 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of osmosis in fluid movement across a semi-permeable membrane?

  • It combines fluids from different solute concentrations.
  • It allows fluid to move from high to low solute concentration.
  • It restricts the movement of proteins across membranes.
  • It facilitates fluid movement from low to high solute concentration. (correct)

    • Which of the following pressures exerted by the capillary is highest at the arterial end?

  • Interstitial oncotic pressure
  • Arterial hydrostatic pressure (correct)
  • Venous oncotic pressure
  • Venous hydrostatic pressure

    • Which electrolyte is the principal extracellular cation responsible for maintaining the osmotic equilibrium?

  • Na⁺ (correct)
  • K+
  • Ca²+
  • Mg²+

    • What role does aldosterone play in electrolyte and water balance?

    <p>It promotes sodium reabsorption and water retention.</p> Signup and view all the answers

    Which of the following conditions can lead to dehydration?

    <p>Diarrhea and vomiting</p> Signup and view all the answers

    What is the most common reason for diarrhea leading to hypovolemia?

    <p>Food poisoning</p> Signup and view all the answers

    Which symptom is NOT typically associated with dehydration in infants?

    <p>High fever</p> Signup and view all the answers

    What is a characteristic symptom of nephrotic syndrome that may cause edema in a child?

    <p>Pitting edema</p> Signup and view all the answers

    Which of the following best describes the role of water in metabolic processes?

    <p>Serves as a reactant</p> Signup and view all the answers

    Which compartment of body water is considered extracellular fluid?

    <p>Plasma</p> Signup and view all the answers

    What is one function of water relevant to homeostasis?

    <p>Acts as a universal solvent</p> Signup and view all the answers

    How does water contribute to temperature regulation in the body?

    <p>By evaporating and cooling the surface</p> Signup and view all the answers

    What form of edema might be observed in a well-nourished child with swelling in the face and lower extremities?

    <p>Pitting edema</p> Signup and view all the answers

    Which buffer system primarily acts in response to an increase in $H^+$ ions in the extracellular fluid (ECF)?

    <p>Carbonic acid-bicarbonate buffer system</p> Signup and view all the answers

    Which of the following components is involved in the phosphate buffer system?

    <p>$H_2PO_4^-$</p> Signup and view all the answers

    What role do –COO- groups in proteins serve in the buffering system?

    <p>They act as proton acceptors.</p> Signup and view all the answers

    How does the equilibrium shift in the carbonic acid-hydrogen carbonate buffer system when $H^+$ ions are added?

    <p>It shifts to the left, decreasing $H_2CO_3$ concentration.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of the hemoglobin buffer system?

    <p>Works primarily in the extracellular fluid.</p> Signup and view all the answers

    What happens to the volume of extracellular fluid (ECF) during dehydration?

    <p>It decreases.</p> Signup and view all the answers

    Which clinical symptom is NOT typically associated with severe dehydration?

    <p>Widened blood vessels</p> Signup and view all the answers

    What increases in the body as a result of dehydration?

    <p>Osmotic pressure</p> Signup and view all the answers

    Which treatment is appropriate for overhydration?

    <p>Administration of hypertonic saline</p> Signup and view all the answers

    How do Van der Waals forces contribute to molecular interactions?

    <p>They result from fluctuations in charge density.</p> Signup and view all the answers

    What drives the self-association of nonpolar compounds in an aqueous environment?

    <p>Hydrophobic interactions</p> Signup and view all the answers

    What is a characteristic of a nucleophile in metabolic reactions?

    <p>It attacks electron-deficient sites.</p> Signup and view all the answers

    Which of the following interactions helps shape biomolecular structure through the attraction of oppositely charged groups?

    <p>Electrostatic interactions</p> Signup and view all the answers

    What percentage of body fluid is composed of intracellular fluid in a typical adult?

    <p>63%</p> Signup and view all the answers

    Which of the following is a component of extracellular fluid?

    <p>Plasma</p> Signup and view all the answers

    What accounts for the largest proportion of extracellular fluid?

    <p>Interstitial fluid</p> Signup and view all the answers

    How much water is typically lost through urine in a day?

    <p>1.5 L/day</p> Signup and view all the answers

    Which of these ions has a normal serum range of 135 - 145 mEq/L?

    <p>Sodium (Na+)</p> Signup and view all the answers

    What mechanism actively moves substances against their concentration gradient?

    <p>Active transport</p> Signup and view all the answers

    In women, what proportion of total body fluid is extracellular fluid?

    <p>1/3</p> Signup and view all the answers

    Which of the following is NOT a type of extracellular fluid?

    <p>Intracellular fluid</p> Signup and view all the answers

    What is the primary role of water in facilitating digestion?

    <p>It forms saliva necessary for digestion.</p> Signup and view all the answers

    In the context of dehydration, what clinical sign is most indicative of hypovolemia in a child?

    <p>Decreased skin turgor.</p> Signup and view all the answers

    Which factor is primarily responsible for regulating water balance in the body?

    <p>Antidiuretic hormone (ADH).</p> Signup and view all the answers

    What might cause alkalosis in the human body?

    <p>Excessive acid loss through vomiting.</p> Signup and view all the answers

    What percentage of the brain is composed of water?

    <p>75%</p> Signup and view all the answers

    What is the significance of elevated hematocrit levels in a dehydrated child?

    <p>Reflects concentrated blood due to low plasma volume.</p> Signup and view all the answers

    Which property of water contributes to its role as a universal solvent?

    <p>Its hydrogen bonding capabilities.</p> Signup and view all the answers

    Which of the following best describes nephrogenic diabetes insipidus?

    <p>Inability to concentrate urine due to unresponsiveness to ADH.</p> Signup and view all the answers

    Study Notes

    Water's Role in the Body

    • Water is the major component of most body parts
    • Makes up 83% of blood and 75% of the brain
    • Essential for brain hormone and neurotransmitter production
    • Regulates body temperature (through sweating and respiration)
    • Acts as a shock absorber for the brain and spinal cord
    • Transports oxygen throughout the body
    • Comprises 22% of bones and 75% of muscles
    • Forms saliva for digestion
    • Converts food to components needed for survival and digestion
    • Keeps mucosal membranes moist
    • Allows cells to grow, reproduce, and survive
    • Flushes body waste, primarily through urine
    • Lubricates joints

    Biomedical Importance of Water

    • Water is a universal solvent due to its dipolar structure and capacity for forming hydrogen bonds
    • Water is an excellent nucleophile, participating in many metabolic reactions
    • Water balance depends on hypothalamic mechanisms controlling thirst, ADH, kidney function and evaporative losses
    • Nephrogenic diabetes insipidus results from unresponsiveness of renal tubular osmoreceptors to ADH
    • Water dissociates into hydroxide ions and protons, affecting pH
    • Buffers (like bicarbonate) regulate extracellular fluid pH (between 7.35 and 7.45)
    • Acidosis (blood pH <7.35) arises from conditions like diabetic ketosis or lactic acidosis
    • Alkalosis (pH >7.45) may be caused by vomiting acidic gastric contents

    Case Study of a Dehydrated Child

    • A three-year-old child presented with persistent vomiting and diarrhea for 24 hours.
    • On examination, the child was lethargic, irritable, and had dry mucous membranes and decreased skin turgor.
    • Vital signs: Heart rate of 150 bpm, blood pressure of 80/50 mmHg, and temperature of 38.5°C
    • Laboratory findings: Elevated serum sodium and hematocrit levels

    Look at Eyes for Dehydration

    • Photographs/illustrations demonstrate the difference in eye appearance between a child with normal hydration and dehydration. Dehydration shows shrunken eyes.

    Probable Diagnosis

    • The case study likely indicates hypovolemia (dehydration)
    • The primary mechanism for elevated serum sodium levels in dehydration is an imbalance between water loss and sodium retention.
    • Elevated hematocrit in dehydration suggests concentration of red blood cells

    Edema -- Hypervolemia/Volume Overload

    • A seven-year-old child presented with swelling in her face and lower extremities.
    • Swelling worsened during the evening and improved slightly upon waking in the morning.
    • Examination: Well-nourished, periorbital puffiness, and pitting edema in lower extremities.

    Possible Cause of Edema

    • Potential causes of edema in the child include nephrotic syndrome, heart failure, malnutrition, or allergic reaction.

    Water Balance

    • Water is crucial for life as the solvent of life
    • Water provides the aqueous medium for biochemical reactions in the organism
    • Water acts as a reactant in various metabolic reactions
    • Water serves as a transport vehicle for solutes in the body

    Homeostasis

    • The body's ability to maintain a stable internal environment despite external changes
    • Water plays a significant role in maintaining homeostasis through its properties as an insulator, its resistance to temperature change, and as a universal solvent, its role as a coolant and protecting against temperature extremes by insulating frozen lakes

    Distribution of Body Water

    • Water is distributed in the body's compartments: intracellular fluid (ICF - inside cells) and extracellular fluid (ECF - outside cells).
    • ICF accounts for about 63% of total body water, ECF about 37%

    Major Compartments for Fluids

    • Intracellular fluid (ICF): Located inside cells (63% of total body water)
    • Extracellular fluid (ECF): Located outside cells (37% of total body water)
      • Interstitial fluid: Between cells (25%)
      • Intravascular fluid: Within blood vessels (5-8%)
      • Transcellular fluid: Cerebrospinal, pericardial, synovial, and gastrointestinal fluids (1-2%)

    Distribution of Water: Male vs. Female

    • The distribution of water in the body varies slightly between males and females, though general proportions are roughly 2/3 intracellular fluid (ICF) and 1/3 extracellular fluid (ECF)

    Water Steady State

    • Intake of water must equal the output of water in the body
    • Water gain comes from food and drink, and metabolism (0.3 L/day).
    • Water loss occurs via skin (insensible water loss 0.9 L/day), lungs, urine (1.5 L/day), and feces (0.1 L/day)

    Electrolytes Composition of Body Fluids

    • Electrolytes are essential for normal bodily function, including maintaining osmotic balance
    • Crucial electrolytes include:
      • Sodium (Na+): Primary extracellular cation (135-145 mEq/L)
      • Potassium (K+): Primary intracellular cation (3.5-5.5 mEq/L)
      • Calcium (Ca2+): (8.5-10.5 mg/dL)
      • Ionized Calcium: (4.5-5.5 mg/dL)
      • Magnesium (Mg2+): (1.5-2.5 mEq/L)
      • Bicarbonate (HCO3-): (24-30 mEq/L)
      • Chloride (Cl-): (95-105 mEq/L)
      • Phosphate (PO43-). (2.8-4.5 mg/dL)

    Mechanisms Controlling Fluid and Electrolyte Movement

    • Diffusion: Passive movement of substances from a high concentration to a low concentration
    • Facilitated diffusion: Passive transport with the assistance of special transport proteins
    • Active transport: Movement of substances against a concentration gradient, requiring energy
    • Osmosis: Movement of water across a semi-permeable membrane from a low solute concentration to a high solute concentration
    • Hydrostatic pressure: Pressure exerted by fluid against a wall
    • Oncotic pressure: Osmotic pressure exerted by proteins

    Fluid Exchange Between Capillary and Tissue

    • Capillary pressure and interstitial fluid pressure influence Fluid exchange
    • Comparing Arterial and Venous ends of capillaries

    Electrolyte Composition of Body Fluids

    • Electrolytes are essential for maintaining osmotic equilibrium and water balance
    • Significant difference between extracellular fluid (ECF) and intercellular fluid (ICF) concentrations is crucial for effective cell function.
    • Sodium (Na+) is the dominant extracellular cation, while potassium (K+) is the major intracellular cation

    Regulation of Electrolyte Balance

    • Electrolyte and water balance are regulated together by kidneys
    • Aldosterone; ADH (antidiuretic hormone); Renin-angiotensin system are crucial hormones

    Dehydration

    • Dehydration is characterized by water depletion in the body, caused by deficient intake or excessive loss
    • Two types: loss of water alone and loss of electrolytes and water
    • Causes of dehydration include: diarrhea, vomiting, excessive sweating, adrenocortical dysfunction, kidney disease, and deficiency of ADH

    Dehydration Features

    • Decrease in extracellular fluid volume (ECF) and electrolyte concentrations
    • Water is drawn from inside cells, causing them to shrink, disrupting cellular metabolism
    • Antidiuretic hormone (ADH) secretion increases to conserve water
    • Plasma protein and blood urea concentrations increase
    • Electrolytes are lost from the body (e.g., Na+, K+)

    Clinical Symptoms of Severe Dehydration

    • Increased pulse rate, decreased blood pressure, sunken eyeballs, decreased skin turgor, lethargy, confusion, and coma
    • Therapy: Intake of plenty/additional fluids, 5% glucose

    Overhydration

    • Overhydration involves excessive water retention in the body due to high intake or issues with kidney function/ADH
    • Clinical manifestations include headaches, lethargy, and seizures.
    • Therapy requires restricting water intake and possibly administering hypertonic saline

    Other Interactions

    • Van der Waals forces: Weak intermolecular forces (example: dipole-dipole interactions; Hydrogen bonding; dispersion forces)
    • Hydrophobic interactions: Nonpolar compounds tend to aggregate together in aqueous environments because they minimize their contact with water molecules
    • Electrostatic interactions: Occur between charged groups in biological molecules (example: salt bridges)

    Nucleophiles

    • Nucleophiles are electron-rich molecules that readily donate electrons to form bonds
    • Examples in biology include water, phosphates, and the nitrogen atoms in amines.
    • Water is an important biological nucleophile that plays a key role in hydrolysis during metabolic reactions.

    Electrophiles

    • Electrophiles are electron-poor molecules that readily accept electrons to form bonds
    • Examples include common carbonyl carbons in amides, esters, and aldehydes.

    Dissociation of Water

    • Water dissociates into hydrogen ions (H+) and hydroxide ions (OH−)
    • A water molecule (H₂O) can dissociate into a hydrogen ion (H+) and a hydroxide ion (OH−).

    Henderson-Hasselbalch Equation

    • Describes the relationship between pH, pKa, and the concentrations of an acid and its conjugate base
    • Used to calculate the pH of buffer solutions

    pH & Buffers

    • pH: Measure of hydrogen ion concentration in a solution (logarithmic scale from 0-14).
    • pKa: The negative log of acid dissociation constant, reflecting the strength of a weak acid
    • Buffers: Solutions that resist changes in pH upon addition of acid or base by reacting with the added acid or base and neutralizing it.

    pH Scale

    • pH range of 0-14, with 7 being neutral, less than 7 acidic, greater than 7 basic

    • The pH of a substance is linked to the ratio of hydrogen and hydroxide ions

    • It measures the concentration of H+ and OH- ions

    • pH values correspond to concentrations of H+ and OH− ions.

    • Buffers*

    • Weak acids or bases that resist pH change during neutralization reactions.

    • Contain a weak acid and its conjugate base or a weak base and its conjugate acid

    • Ex: Acetate buffer (CH3COOH and CH3COO-)

    • Buffer Capacity*

    • A measure of how much acid or base a buffer solution can neutralize before its pH changes significantly.

    • Maximum when the concentrations of a weak acid and its salt/weak base and its salt are equal.

    • Buffer Systems in Body Fluids*

    • Body fluids contain important buffer systems (e.g., phosphate, carbonic acid-bicarbonate, and protein buffers.)

    • These systems help maintain a stable pH in the blood and other fluids.

    • The Carbonic Acid-Bicarbonate Buffer System*

    • Most important buffer system in the body for maintaining blood pH. Its key components are carbonic acid (H2CO3) and bicarbonate(HCO3-).

    • Phosphate Buffer System*

    • This buffer plays a crucial role in regulating the pH of body fluids, particularly in plasma and erythrocytes. Its critical components are dihydrogen phosphate and monohydrogen phosphate

    • Proteins as Buffers*

    • Proteins in the body act as buffers by containing functional groups (e.g., -COO- and -NH3+). These groups can accept or donate protons (H+).

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Lec2 Distribution of Water, pH, Buffers PDF

    Description

    This quiz explores the critical functions of water in the human body, highlighting its importance in maintaining physiological processes. Learn about water's role in temperature regulation, nutrient transport, and as a solvent in biochemical reactions. Understand how water impacts overall health and body function.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser