Nursing Chapter 3 Quiz: Fluids and Electrolytes

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does angiotensin-converting enzyme (ACE) do?

Converts angiotensin I to angiotensin II.

What are the major functions of angiotensin II? (Select all that apply)

Causes vasoconstriction (correct)

Stimulates aldosterone secretion (correct)

Inhibits blood pressure

Promotes sodium and water reabsorption (correct)

Aldosterone promotes the excretion of sodium.

False

What causes the release of ADH?

A drop in blood volume and blood pressure. Signup and view all the answers

Which hormones are included among natriuretic peptides?

Brain natriuretic peptide (BNP) Signup and view all the answers

What happens during isotonic alterations?

Fluid changes are proportional to sodium changes Signup and view all the answers

What triggers the sensation of thirst?

When water loss equals 2% of body weight or an increase in osmolality occurs. Signup and view all the answers

Hypertonic alterations develop when the osmolarity of the ECF is below normal.

False Signup and view all the answers

What is the net filtration pressure at the arterial end of the capillary?

19 mmHg Signup and view all the answers

What two main compartments distribute body fluids?

Intracellular fluid (ICF) and extracellular fluid (ECF) Signup and view all the answers

Which of the following conditions can lead to increased capillary hydrostatic pressure?

Heart failure Signup and view all the answers

Two thirds of the body’s water is ________ fluid (ICF).

intracellular Signup and view all the answers

What does edema refer to?

Swelling caused by the accumulation of fluid in interstitial spaces. Signup and view all the answers

What is a contributing factor to decreased plasma oncotic pressure?

Decreased synthesis of plasma proteins Signup and view all the answers

What is the standard value for total body water (TBW) in a 70-kg adult male?

60% Signup and view all the answers

What process describes the movement of fluid back and forth across the capillary wall?

Net filtration Signup and view all the answers

Increased capillary permeability is usually associated with inflammation.

True Signup and view all the answers

The percentage of total body water (TBW) increases with age.

False Signup and view all the answers

What role does aldosterone play in sodium balance?

Aldosterone promotes sodium and water retention in the kidneys. Signup and view all the answers

Decreased synthesis of proteins may result from ______.

malnutrition Signup and view all the answers

What are the four main forces that determine fluid movement across the capillary membrane?

Capillary hydrostatic pressure, plasma oncotic pressure, interstitial hydrostatic pressure, interstitial oncotic pressure Signup and view all the answers

What condition is characterized by the excessive accumulation of fluid within the interstitial spaces?

Edema Signup and view all the answers

What can cause lymphedema?

Surgical removal of lymph nodes Signup and view all the answers

Match the following electrolytes with their primary locations:

Sodium = Extracellular Fluid Potassium = Intracellular Fluid Calcium = Bone and teeth Chloride = Extracellular Fluid Signup and view all the answers

What is the primary source of body water?

Drinking fluids, ingestion of food, and water from oxidative metabolism Signup and view all the answers

Infants have a higher percentage of total body water compared to adults.

True Signup and view all the answers

Match the following body fluid types with their respective compartments:

ICF = Intracellular fluid ECF = Extracellular fluid Plasma = Intravascular fluid Interstitial fluid = Fluid between cells and capillaries Signup and view all the answers

Study Notes

Overview of Body Fluids

Body fluids are essential for cellular and tissue function, distributed among different compartments.
Total body water (TBW) comprises approximately 60% of an adult male's body weight, translating to around 42 liters.
TBW is split into intracellular fluid (ICF) and extracellular fluid (ECF), with ICF making up about 66% of TBW.

Aging and Body Fluid Distribution

TBW percentage varies with age; newborns have about 75-80% TBW, which decreases with growth.
Infants are at a higher risk for fluid imbalances due to high metabolic rates and surface area.
Older adults experience a decline in TBW, attributed to increased fat and decreased muscle mass along with reduced sodium and water regulation by kidneys.

Fluid and Electrolyte Balance

Osmotic forces primarily govern fluid movement between ICF and ECF.
Sodium is crucial for ECF osmotic balance; potassium maintains ICF osmotic balance.
Disturbances in fluid balance can lead to life-threatening conditions.

Water Sources and Loss

Daily water intake comes from drinking fluids, food, and metabolic processes, with significant loss primarily through renal excretion.
Insensible losses (from skin and respiration) also contribute to total fluid loss.

Starling Hypothesis and Fluid Movement

Fluid movement across capillary walls is described by the Starling hypothesis, which balances forces favoring and opposing filtration.
Key forces include capillary hydrostatic pressure (outward) and oncotic pressure (inward).

Edema

Edema represents excessive fluid accumulation in interstitial spaces, often a distribution issue rather than an absolute excess.
Causes include:
- Increased capillary hydrostatic pressure
- Decreased plasma oncotic pressure
- Increased capillary permeability
Edema can lead to both tissue swelling and potential dehydration of the intravascular compartment.

Key Terminology

Osmolality: Measure of solute concentration in a solution.
Oncotic Pressure: Pressure exerted by proteins in plasma that attracts water into the circulatory system.
Net Filtration: The movement of fluid across capillaries, influenced by both hydrostatic and oncotic pressures.

Conclusion

Understanding fluid compartments and their regulation is critical for recognizing disturbances in hydration and electrolyte balance. Proper balance is vital for maintaining homeostasis and cellular function.### Lymphatic Obstruction and Edema Formation
Lymphatic obstruction leads to fluid accumulation in interstitial spaces, causing lymphedema.
Common causes include infections, tumors, surgical removal of lymph nodes, and venous obstruction.
Increased capillary hydrostatic pressure results from conditions like right heart failure and renal failure, pushing fluid into surrounding tissues.
Edema can result from increased capillary permeability due to inflammation or trauma.

Capillary Filtration Forces

Capillary pressures vary between arterial (35 mmHg) and venous ends (18 mmHg).
Net filtration pressure determines fluid exchange; it combines hydrostatic and oncotic pressures.
Capillary hydrostatic pressure promotes filtration, while oncotic pressure inhibits it.
Net filtration pressure is positive in arterial capillaries (19 mmHg) and negative in venous capillaries (28 mmHg).

Mechanisms of Edema Formation

Increased hydrostatic pressure, decreased oncotic pressure, and increased capillary permeability all contribute to edema formation.
Conditions like nephrotic syndrome and malnutrition lead to protein loss, decreasing plasma oncotic pressure.
Swelling can be localized (e.g., cerebral or pulmonary edema) or generalized, affecting the entire body.

Clinical Manifestations of Edema

Edema may present as swelling, puffiness, and restricted movement in affected areas.
Dependent edema accumulates in gravity-dependent areas (feet, legs when standing; sacral area when supine).
Erosion of nutrient transport can occur due to increased tissue pressure on capillaries, leading to slower healing processes.

Sodium, Chloride, and Water Balance

Sodium is vital for regulating extracellular fluid balance, influencing blood pressure and osmoregulation.
Normal serum sodium concentration is maintained (135-145 mEq/L) primarily through renal absorption.
Major regulatory hormones include aldosterone (increases sodium and water retention) and antidiuretic hormone (ADH), which responds to blood pressure and volume changes.

Renin-Angiotensin-Aldosterone System

Renin is released in response to reduced blood pressure or serum sodium, initiating a cascade that produces angiotensin II.
Angiotensin II functions to vasoconstrict and stimulate aldosterone secretion, enhancing sodium and water retention.
Baroreceptors detect changes in blood volume/pressure and trigger the release of ADH to maintain fluid balance.

Evaluation and Treatment of Edema

Specific conditions causing edema must be diagnosed for targeted treatment.
Symptomatic relief may include limb elevation, compression, and diuretics usage.
Reducing prolonged standing and salt intake can also help manage edema effectively.### Atrial Natriuretic Peptide (ANP) and Brain Natriuretic Peptide (BNP)
ANP and BNP are secreted in response to increased transmural atrial pressure due to elevated intra-atrial volume, often seen in heart failure.
These peptides promote sodium and water excretion in the kidneys, helping to reduce blood volume and pressure.
Urodilatin is released from distal tubular cells in the kidneys under conditions of increased arterial pressure and renal blood flow, acting as an antagonist to the renin-angiotensin-aldosterone system.
Once atrial pressure decreases, the secretion of ANP and BNP is inhibited.

Sodium and Water Balance

Alterations in sodium and water balance are interconnected, reflecting changes in osmotic gradients from sodium gain or loss.
Water imbalances may manifest as changes in tonicity: isotonic, hypertonic, or hypotonic, affecting electrolyte concentration relative to water.

Isotonic Alterations

Isotonic solutions have the same solute concentration as plasma; changes in total body water (TBW) are associated with proportional sodium changes.
Chloride levels parallel sodium alterations due to passive transport mechanisms, maintaining electroneutrality with bicarbonate.

Water Balance Regulation

Thirst sensation triggers water intake when water loss reaches 2% of body weight or when osmolality rises.
Hypothalamic osmoreceptors activate thirst in response to dry mouth, hyperosmolality, or volume depletion, prompting fluid intake to restore plasma volume and lower ECF osmolality.

Antidiuretic Hormone (ADH)

Arginine-vasopressin (ADH) secretion occurs when plasma osmolality rises or blood volume decreases, facilitating renal water reabsorption.
Increased ADH enhances renal tubular permeability to water, promoting higher water retention and adjustment of plasma volume and osmolality.

Isotonic Fluid Imbalances

Isotonic fluid loss can lead to hypovolemia, commonly from conditions like hemorrhage or excessive sweating.
Indicators of hypovolemia include weight loss, dry skin, decreased urine output, elevated hematocrit, and symptoms like rapid heart rate.
Severe instances can lead to hypovolemic shock characterized by significant hypotension.

Isotonic Fluid Excesses

Hypervolemia can occur due to excessive saline administration or aldosterone hypersecretion leading to sodium and water retention.
Symptoms include weight gain, distended neck veins, elevated blood pressure, and potential development of edema or pulmonary complications.

Hypertonic Fluid Alterations

Hypertonic alterations arise when ECF osmolality exceeds normal levels, causing cellular shrinkage.
Common causes include water loss or increased solute concentrations in the ECF, significantly affecting fluid balance.

Studying That Suits You

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

Description

Test your knowledge on the cellular environment focusing on fluids and electrolytes, as well as acids and bases. This quiz is based on Chapter 3 from the book by Alexa K. Doig and Sue E. Huether. Prepare to assess your understanding of key concepts and applications in nursing.