ch 25 acid base fluids

Body Fluid Percentage

Human body fluid ranges from 45% to 75%.

Intracellular Fluid (ICF)

Fluid within cells, two-thirds of total body fluid.

Extracellular Fluid (ECF)

Fluid outside cells, includes interstitial fluid and plasma.

Interstitial Fluid (IF)

Fluid surrounding cells, two-thirds of ECF.

Blood Plasma

ECF within blood vessels, more permeable than ICF.

Adipose Tissue Water Content

Adipose tissue contains about 20% water.

Skeletal Muscle Water Content

Skeletal muscle contains about 75% water.

Fluid Intake

Addition of water to the body, 2500 mL/day.

Metabolic Water

Water produced from cellular respiration, 200 mL/day.

Fluid Output

Loss of water from body, 2500 mL/day.

Sensible Water Loss

Measurable loss through feces and urine.

Insensible Water Loss

Not measurable; includes expired air and sweat.

Obligatory Water Loss

Water loss that always occurs, essential for waste.

Facultative Water Loss

Controlled loss, dependent on hydration and hormones.

Volume Depletion

Isotonic fluid loss exceeds isotonic fluid gain.

Volume Excess

Isotonic fluid gain exceeds isotonic fluid loss.

Dehydration

Water loss exceeds solute loss, blood plasma hypertonic.

Hypotonic Hydration

Excess water retention, plasma becomes hypotonic.

Fluid Sequestration

Normal total body fluid, abnormal distribution.

Thirst Center Regulation

Stimulated by decreased blood volume and pressure.

Electrolytes

Dissociate in solution, conduct electrical current.

Sodium Ion (Na+)

Principal cation in ECF, regulates osmotic pressure.

Sodium Balance

Normal concentration 135-145 mEq/L, daily intake 2g.

Hypernatremia

Above normal sodium levels in blood.

Hyponatremia

Below normal sodium levels in blood.

Osmolarity Changes

Altered by sodium concentration, affects fluid movement.

Fluid Movement

Occurs by osmosis in response to osmolarity changes.

Fluid Compartments

Intracellular and extracellular compartments are chemically distinct.

Potassium (K+)

Essential for maintaining electrochemical gradients in cells.

Hyperkalemia

Elevated potassium levels in the blood.

Hypokalemia

Decreased potassium levels in the blood.

Chloride ion (Cl−)

Most abundant anion in extracellular fluid (ECF).

Hyperchloremia

Increased chloride levels in the blood.

Hypochloremia

Decreased chloride levels in the blood.

Calcium ion (Ca2+)

Most abundant electrolyte in bones and teeth.

Hypercalcemia

Elevated calcium levels in the blood.

Hypocalcemia

Decreased calcium levels in the blood.

Phosphate ion

Most abundant anion in intracellular fluid (ICF).

Magnesium ion (Mg2+)

Second most abundant cation in intracellular fluid.

Renin

Enzyme released by kidneys to regulate blood pressure.

Angiotensin II

Hormone that constricts blood vessels and increases blood pressure.

Aldosterone

Hormone that decreases urine output to increase blood volume.

Antidiuretic hormone (ADH)

Hormone that promotes water retention in kidneys.

Atrial natriuretic peptide (ANP)

Hormone that increases urine output to reduce blood volume.

Sarcoplasmic reticulum

Organelle that stores calcium in muscle cells.

Na+/K+ pump

Transporter that moves sodium out and potassium into cells.

Electrolyte balance

Maintaining proper levels of ions in body fluids.

Intracellular buffer

Substance that helps maintain pH within cells.

Extracellular fluid (ECF)

Fluid outside of cells, rich in sodium and chloride.

Intracellular fluid (ICF)

Fluid within cells, rich in potassium and phosphate.

Angiotensin II

Stimulates aldosterone and ADH release for blood pressure.

Aldosterone

Hormone increasing sodium retention and potassium excretion.

Antidiuretic Hormone (ADH)

Hormone promoting water reabsorption in kidneys.

Renin-Angiotensin System

Hormonal pathway regulating blood pressure and volume.

Sodium Retention

Increased sodium in blood raises blood volume.

Potassium Excretion

Aldosterone causes kidneys to release potassium.

Blood Volume

Total amount of blood in circulation.

Blood Pressure

Force exerted by circulating blood on vessel walls.

Fluid Intake

Increased drinking raises blood volume and pressure.

Aquaporins

Channels that facilitate water reabsorption in kidneys.

Vasoconstriction

Narrowing of blood vessels increases blood pressure.

Peripheral Resistance

Resistance in systemic circulation affecting blood pressure.

Atrial Natriuretic Peptide (ANP)

Hormone reducing blood volume and pressure from heart.

Vasodilation

Widening of blood vessels decreases blood pressure.

Glomerular Filtration Rate (GFR)

Rate of blood filtration in kidneys.

Nephron Tubules

Kidney structures involved in urine formation.

Fluid Loss

Decreased water retention leads to increased urine output.

Renin

Enzyme initiating the renin-angiotensin-aldosterone system.

Osmolarity

Concentration of solutes in blood affecting fluid balance.

Principal Cells

Kidney cells responsive to aldosterone for sodium reabsorption.

Stretch Response

Heart's reaction to increased blood volume and pressure.

Acid-base balance

Regulation of hydrogen ion concentration in blood.

Normal pH range

Normal blood pH is 7.35 to 7.45.

Hydrogen ion (H+)

Concentration affects acid-base balance in body.

Fixed acid

Nonvolatile acids produced from metabolic processes.

Volatile acid

Carbonic acid formed from CO2 and water.

Carbonic anhydrase

Enzyme facilitating carbonic acid formation.

Kidney function

Regulates fixed acids and maintains pH balance.

Lactic acid

Produced during glycolysis, a fixed acid.

Phosphoric acid

Generated from nucleic acid metabolism, a fixed acid.

Ketoacids

Produced from fat metabolism, a fixed acid.

Respiratory rate

Influences acid-base balance through CO2 elimination.

HCO3− (Bicarbonate)

Buffer reabsorbed by kidneys to maintain pH.

Acid input sources

Includes nutrients from GI tract and metabolic waste.

Antacid ingestion

Can decrease blood H+ concentration, affecting pH.

Renal tubules

Adjust bicarbonate and hydrogen ion reabsorption.

Physiologic buffering system

Kidneys eliminate excess acid or base over hours.

Chemoreceptors

Detect changes in CO2, H+, and O2 levels.

Respiration center

Regulates breathing rate based on blood gas levels.

Carbonic acid regulation

Dependent on CO2 levels in the body.

Acid-base balance importance

Critical for proper body functions and homeostasis.

Diarrhea effect

Can increase blood H+ concentration due to loss.

Chemical buffering systems

Prevent pH changes within minutes using molecules.

H+ binding

Chemical buffers can bind and release H+ quickly.

Weak base

Can bind excess H+ to minimize acidity.

Weak acid

Can release H+ to counteract alkalinity.

Physiologic buffering systems

Kidneys eliminate excess acid or base long-term.

Protein buffering system

Accounts for 75% of body fluid buffering.

Intracellular proteins

Proteins inside cells that buffer pH changes.

Plasma proteins

Proteins in blood plasma aiding in buffering.