Biochem PPT 1 Midterm PDF

Learning Objectives: Describe the acid-base balance in the body, Define pH and explain its significance in including the normal pH range of blood biol...

Learning Objectives: Describe the acid-base balance in the body, Define pH and explain its significance in including the normal pH range of blood biological systems, particularly in human (7.35 to 7.45) and the implications of physiology. deviations from this range. Identify and explain the mechanisms of Analyze the roles of the respiratory and buffer systems, focusing on how they renal systems in regulating blood pH, maintain pH stability by neutralizing excess detailing how changes in carbon dioxide acids or bases, particularly through the levels affect acidity and how kidneys bicarbonate-carbonic acid buffer system. manage hydrogen ions and bicarbonate. Apply knowledge of acid-base imbalances to clinical scenarios, recognizing conditions such as acidosis and alkalosis, and their physiological consequences on patient health.  Water Buffer Mechanism pH Interactions between water, pH and buffer systems in maintaining homeostasis during metabolic activities and stress responses. Water Constitutes about 50% to 75% of body weight (depending on age and sex). Integral to numerous physiological processes. Key Functions of Water in the Body: Cellular Transport of Regulation of Lubrication Waste Digestion Skin Health Cognitive Function and Nutrients Body of Joints Removal Function Homeostasis and Oxygen Temperature Key Functions of Water in the Body: CELLULAR FUNCTION TRANSPORT OF REGULATION OF AND HOMEOSTASIS: NUTRIENTS AND BODY TEMPERATURE: OXYGEN: Maintaining health and Through the process of integrity of the cell: Primary component of sweating, water helps facilitating cellular blood w/c transports regulate body homeostasis - allowing nutrients and oxygen to temperature. When the cells to maintain their cells throughout the body body heats up, sweat shape and function (ensuring all bodily evaporates from the skin effectively. functions can occur surface, cooling the body efficiently). down. Key Functions of Water in the Body: LUBRICATION OF WASTE REMOVAL: DIGESTION: JOINTS: Kidneys rely on water to Aids in digestion by Acts as lubricant for joints, filter waste products from dissolving nutrients and reducing friction during the blood and excrete them facilitating their movement. through urine. absorption in the Cushion sensitive tissues Adequate hydration is intestines. crucial for preventing like the brain and spinal kidney stones and urinary Prevent constipation by cord. tract infections. keeping stools soft. Key Functions of Water in the Body: SKIN HEALTH: COGNITIVE FUNCTION: Proper hydration keeps Hydration significantly skin moisturized, impacts brain function; enhancing texture and even mild dehydration can appearance while helping impair mood, memory, and to prevent dryness and overall cognitive irritation. performance. Water Distribution in the Human Body Intracellular Fluids (ICF) Extracellular Fluids (ECF)  ICF is vital for various cellular processes, Water Distribution in the Human Body including: Nutrient Transport Intracellular Fluids (ICF) Waste Removal Fluid contained within cells; about two-thirds of Maintaining Cell Volume total body water (40% of total body weight). pH of ICF: ranges from 6.8 to 7.4 - Composed of: water, along with various solutes slightly more acidic than extracellular fluid. such as ions and proteins. MAJOR ELECTROLYTES found in IF include: Potassium (K+): most abundant cation, crucial for cellular functions. Phosphate (PO3-): important for energy transfer and storage (e.g., ATP). Magnesium (Mg2+): involved in numerous enzymatic reactions. Proteins: contribute to cellular structure and function, maintaining osmotic balance.  Water Distribution in the Human Body Extracellular Fluids (ECF) Surrounds cells. Accounts for about 20% of total body weight (one-third of total body water), with plasma constituting about 5% and interstitial fluid making up the majority. DIVIDED INTO THREE MAIN COMPARTMENTS: 1. Interstitial Fluid: fills the spaces between cells and facilitates the exchange of nutrients and waste products. 2. Plasma: liquid component of blood, making up about 55% of blood volume, primarily consisting of water (90%) and proteins (10%). 3. Transcellular Fluid: specialized fluids such as: cerebrospinal fluid, synovial fluid in joints, lymph, and others that are found in specific body compartments. PRIMARY ELECTROLYTES IN ECF: Sodium (Na*): most abundant cation in ECF, critical for maintaining osmotic balance and nerve function. Chloride (CI-) and Bicarbonate (HCO3-): important for maintaining pH balance and participating in various physiological processes. pH of ECF: ranges from 7.3 to 7.5, slightly more alkaline. Maintaining the balance between these two compartments is crucial for homeostasis, affecting: Intracellular ✓ Hydration Status Fluids (ICF) ✓ Nutrient Transport ✓ Overall Cellular Function Disruptions in this balance can lead Extracellular to conditions such as: Fluids (ECF) ▪ Dehydration ▪ Edema Water Intake and Output Normal amount of water intake and Daily Water Intake output for humans varies based on General Recommendations: several factors including: Recommended total daily fluid intake: Age ❑ MEN: 3,000 mL Sex ❑ WOMEN: 2,200 mL Activity Level Recent Guidelines suggest that aged 19-30 years should Environmental Conditions aim for about from all sources: MEN: 3.7 L / 3.700 mL WOMEN: 2.7 L / 2,700 mL FLUID SOURCES: ✓ Daily fluid intake includes water from beverages and food. ✓ Body’s generation from metabolic processes: 230 mL of water. SPECIFIC NEEDS: Pregnant Women: may need an additional 0.3 L. Breastfeeding Women: might require an extra 0.7 to 1.1 L  Daily Water Output Average Output: On average, adults lose about: 2,500 mL/ 2.5 L of water daily through: urine, sweat, respiration and feces. Urine Production: o Minimum urine output for healthy individuals is about: 500 mL/day. o NOTE: But typical daily urine production can be much higher depending on fluid intake and other factors. Variability: Water loss can increase with factors such as: exercise, heat exposure, high dietary protein intake, hot weather, during intense physical activity. DEHYDRATION: when the body loses more fluids than it takes in, leading to an insufficient amount of water for normal bodily functions. Signs and symptoms of dehydration vary significantly: ✓ Between infants and adults. ✓ Depending on the severity of the condition.  Three main types of DEHYDRATION based on relative LOSS OF WATER and ELECTROLYTES Hypertonic Dehydration Hypotonic Dehydration Isotonic Dehydration Occurs when there is a greater In this type, there is a significant Occurs when there is an equal loss of water compared to loss of electrolytes (especially loss of water and electrolytes, electrolytes. sodium) relative to water. which is the most common form of dehydration. Leads to an increase in sodium Results in low sodium levels concentration (hypernatremia). (hyponatremia). Causes: severe diarrhea, Causes: excessive use of Causes: excessive sweating, vomiting, and conditions like diuretics or prolonged vomiting. diarrhea, or blood loss. diabetes insipidus. Management: administering Management: administering Management: focuses on hypotonic fluids to restore hypertonic solutions to replacing lost fluids and balance. correct electrolyte imbalances. electrolytes through isotonic solutions. Assessment of Dehydration Nursing assessment for dehydration involves a comprehensive evaluation that includes: HEMATOCRIT: percentage of blood volume that is Vital Signs: Monitoring for tachycardia, occupied by red blood cells. hypotension, and changes in respiratory rate. HEMATOCRIT TESTING: often part of a complete blood count (CBC); help differentiate between Fluid Intake and Output: Keeping strict dehydration and other conditions that might affect red records to assess fluid balance. blood cell levels. NORMAL HEMATOCRIT LEVELS in ADULTS: Physical Examination: Observing for signs Range from 36% to 54%. such as dry mucous membranes, decreased skin turgor, sunken eyes, and altered mental status. Laboratory Tests: Checking electrolyte levels and hematocrit to evaluate dehydration severity.  Summary Table of Symptoms by Severity SEVERITY NEWBORN/INFANTS MILD ✓ Dry mouth and tongue. ✓ Increased thirst. ✓ Fewer wet diapers (less than six per day). Slightly dry mucous membranes. MODERATE ✓ Dry buccal mucous membranes. ✓ Sunken eyes and cheeks. ✓ Loss of skin turgor (skin does not return quickly when pinched). ✓ Irritability or lethargy. SEVERE ✓ Very dry mouth. ✓ No tears when crying. ✓ Sunken fontanelle (the soft spot on top of the head). ✓ Rapid breathing or heart rate. ✓ Extreme irritability or lethargy, potentially leading to unresponsiveness.  Summary Table of Symptoms by Severity SEVERITY ADULTS MILD ✓ Thirst. ✓ Dry or sticky mouth. ✓ Dark yellow urine. ✓ Mild fatigue or dizziness. MODERATE ✓ Increased thirst. ✓ Less frequent urination (urine may be dark). ✓ Fatigue and dizziness. ✓ Headaches. SEVERE ✓ Extreme thirst and very dry mouth. ✓ Rapid heartbeat and breathing. ✓ Low blood pressure, potentially leading to fainting or confusion. ✓ Little to no urine output, very dark urine. Immediate medical help should be sought if any of the following occur: Severe diarrhea lasting more Inability to keep down fluids. than three days. Signs of confusion or Blood in stool or severe disorientation. abdominal pain. ORAL REHYDRATION: for mild to moderate dehydration, increasing fluid intake through water or oral rehydration solutions (ORS) is recommended. ORS contains specific amounts of water, sugar, and salt to replenish lost electrolytes. INTRAVENOUS FLUIDS: severe dehydration may require hospitalization for IV fluids to rapidly restore hydration levels. ORAL REHYDRATION:  Drink plenty of fluids daily, especially Drink during hot weather or when exercising. Monitor fluid intake during illness, Monitor particularly if experiencing vomiting or diarrhea. Encourage at-risk populations (infants, Encourage children, older adults) to drink regularly even if they do not feel thirsty.  NURSING INTERVENTIONS Interventions for managing dehydration in nursing practice include: ❑ Fluid Replacement: Administering appropriate IVF based on the type of dehydration: ✓ Hypotonic solutions for hypertonic dehydration. ✓ Hypertonic solutions for hypotonic dehydration. ✓ Isotonic solutions for isotonic dehydration. ❑ Monitoring: Regularly assessing vital signs, weight, and urine output to evaluate the effectiveness of treatment. ❑ Education: Providing clients and caregivers with information on recognizing signs of dehydration and the importance of maintaining adequate fluid intake. ❑ Preventive Measures: Implementing strategies to prevent dehydration in at-risk populations, such as older adults and children, by encouraging regular fluid intake during illness or hot weather. Dehydration can lead to serious health issues including: - Kidney Stones - Urinary Tract Infections (UTIs) - Decreased Physical Performance - Cognitive Impairments CONSEQUENCES OF DEHYDRATION * In summary, water is indispensable for maintaining physiological balance and supporting overall health. * Regular intake is essential to meet bodily needs and promote optimal functioning across all systems.  pH, which stands for "potential of hydrogen," is a logarithmic scale used to measure the acidity or basicity of an aqueous solution. pH It is defined as the negative logarithm of the hydrogen ion concentration [H+] in moles per liter: pH = - log|H+1 On this scale: ✓ pH of 7: considered NEUTRAL ✓ values BELOW 7: indicate ACIDITY (higher [H +]) ✓ values ABOVE 7: indicate ALKALINITY (lower [H+]) The pH scale measures the acidity or alkalinity of a solution, with pure water having a neutral pH of 7. This means that the concentration of hydrogen ions (H+) is equal to that of hydroxide ions (OH). Solutions with a pH less than 7 are considered acidic (higher H+ concentration), while those with a pH greater than 7 are basic (lower H+ concentration).  ACIDS BASE Substance that Substance that either releases hydrogen releases hydroxide ions in solution. ions (OH) in solution or accepts H+ ions. Strong acids, such as Strong bases, like sodium hydrochloric acid (HCI), hydroxide (NaOH), fully dissociate in water, completely dissociate in releasing all their H+ water. ions. Weak acids, like acetic Weak bases only acid (found in vinegar), partially dissociate or only partially dissociate, absorb fewer H+ ions. meaning some of their H+ ions remain bonded within the compound. IMPORTANCE OF PH IN THE HUMAN BODY Maintaining proper pH levels is crucial for various physiological functions. The human body regulates pH tightly across different fluids and tissues: Blood pH: The normal range is between 7.35 and 7.45, slightly alkaline. Deviations can lead to acidosis (pH < 7.35) or alkalosis (pH > 7.45), both of which can have serious health implications. Gastric Acid: The stomach has a highly acidic environment (pH 1.5 to 3.5) necessary for digestion and killing pathogens. Cellular pH: The cytosol within cells typically has a pH around 6.8, which is essential for optimal enzyme activity and metabolic processes.  MECHANISMS OF ACID-BASE REGULATION The body employs several mechanisms to maintain acid-base homeostasis: CHEMICAL BUFFERS: these RESPIRATORY REGULATION: RENAL REGULATION: the are substances that can absorb the lungs help control blood pH by kidneys help maintain acid-base excess hydrogen ions or donate regulating carbon dioxide (CO2) balance by excreting excess them when needed to stabilize pH Levels through breathing. Increased acids or bases and levels. Important buffers include CO2, leads to more carbonic acid bicarbonate (HCO3-) and formation, lowering ph. reabsorbing bicarbonate from proteins. urine. Buffers Solutions that resist changes in pH when small amounts of acids or bases are added. Typically consist of a weak acid and its conjugate base, allowing them to absorb excess H+ or OH- ions. Effectiveness of a buffer lies in its ability to neutralize added acids or bases without greatly altering the overall pH. This buffering action is vital for maintaining the pH within a narrow range, which is critical for normal cellular function. MECHANISMS OF ACID-BASE REGULATION The body employs several mechanisms to maintain acid-base homeostasis: How Buffers Work Neutralizing Added Acids: When an acid is added to a buffer solution, the weak base component reacts with the excess H+ ions to form the weak acid, thus minimizing the change in pH. Weak Base + H+ Weak Acid CHEMICAL Neutralizing Added Bases: Conversely, if a base is BUFFERS added, the weak acid component donates H+ ions to neutralize the OH ions from the strong base, forming water and maintaining pH stability. Weak Acid + OH- Weak Base + Water  Key Buffer Systems in Biological Contexts Bicarbonate-Carbonic Phosphate Buffer System Protein Buffers Acid Buffer System Primary buffer system in human blood. Operates mainly within cells and is Proteins, including hemoglobin, play a important for intracellular pH significant role in buffering due to their regulation. amino acid composition, which allows them to bind or release H+ ions. Hemoglobin buffers excess H+ produced during CO2 transport from tissues to lungs. Helps maintain blood pH around 7.4 by It involves dihydrogen phosphate balancing H+ ions through the (H2PO4-) and hydrogen phosphate equilibrium between carbonic acid (HPO 24-), which can donate or accept (H2CO3) and bicarbonate (HCO3-). H+ ions depending on the needs of the cell. When H+ concentrations increase (acidosis), bicarbonate can react with excess H+ to form carbonic acid, which can then be converted to CO2 and exhaled. MECHANISMS OF ACID-BASE REGULATION The body employs several mechanisms to maintain acid-base homeostasis: o The lungs regulate carbon dioxide (CO2) in the blood, which combines with H2O to form H2CO3 (carbonic acid). o Chemoreceptors in the brain sense pH changes and vary the rate and depth of respirations to regulate CO2 levels. RESPIRATORY NOTE: REGULATION o Faster, deeper breathing eliminates CO2 from the lungs, and less H2CO3 is formed, so pH rises. o Alternatively, slower, shallower breathing reduces CO2 excretion, so pH falls. MECHANISMS OF ACID-BASE REGULATION The body employs several mechanisms to maintain acid-base homeostasis: o The partial pressure of arterial CO2 (PaCo2) level reflects the level of CO2 in the blood. o Normal PaCo2: 35 to 45 mm Hg. o Higher PaCO2 level indicates hypoventilation from shallow breathing. o Lower PaCo2 level indicates hyperventilation. RESPIRATORY ❖ Respiratory system: can handle twice as many REGULATION acids and bases as the buffer systems, responds in minutes, but compensation is temporary. o Long-term adjustments require the renal system. MECHANISMS OF ACID-BASE REGULATION The body employs several mechanisms to maintain acid-base homeostasis: o Kidneys can produce HCO3– to replenish lost supplies. o Normal HCO3– level: 22 to 26 mEq/L. o When blood is acidic: kidneys reabsorb HCO3– and excrete H+. o When blood is alkaline: kidneys excrete HCO3– and retain H+. RENAL o Unlike the lungs, the kidneys may take 24 REGULATION hours before starting to restore normal pH.  Health Implications of pH Imbalance Acidosis Alkalosis This condition can result from: Often caused by: ✓ Respiratory Issues (COPD) ✓ Hyperventilation ✓ Kidney Dysfunction ✓ Excessive Vomiting ✓ Excessive Acid Production ✓ Diuretic Use From Metabolic Processes Symptoms may include: It can lead to: ✓ Fatigue ✓ Muscle Twitching ✓ Confusion ✓ Hand Tremors ✓ Lethargy ✓ Other Neurological Symptoms  ABG ANALYSIS Arterial Blood Gas (ABG) analysis is a critical skill for nurses, providing essential information about a patient's oxygenation, ventilation, and acid-base balance. STEPS FOR ABG INTERPRETATION 1. Check the pH Level ✓ Determine if the pH indicates acidosis or alkalosis. 2. Assess PaCO2 ✓ Evaluate whether the changes are respiratory (opposite direction) or metabolic (same direction). 3. Evaluate HCO3- Levels ✓ Confirm if the bicarbonate level supports metabolic acidosis or alkalosis. 4. Determine Compensation ✓ Assess if the body is compensating by examining whether both CO2 and HCO3- levels move in the same or opposite directions relative to pH. 5. Identify Underlying Causes ✓ Based on the findings, diagnose whether the issue is primarily respiratory or metabolic and if compensation is occurring. RESPIRATORY ACIDOSIS: Caused by conditions such as COPD or respiratory failure. RESPIRATORY ALKALOSIS: Often due to hyperventilation from anxiety or pain. COMMON ACID – BASE METABOLIC ACIDOSIS: Results from DISORDERS diabetic ketoacidosis or renal failure. METABOLIC ALKALOSIS: Can occur from prolonged vomiting or overuse of diuretics. Health Implications of pH Imbalance Health Implications of pH Imbalance Importance to Nursing Practice PREPARED BY: ANN MARGARETTE G. 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