Human Body Water Composition

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of total body water is composed of intracellular fluid?

3/4

1/3

2/3 (correct)

1/4

Which electrolyte is the principal cation in extracellular fluid?

Magnesium (Mg2+)

Calcium (Ca2+)

Potassium (K+)

Sodium (Na+) (correct)

What is the approximate percentage of total body water that is distributed in the extracellular fluid?

1/3 (correct)

1/4

2/3

3/4

What is the function of the cell membrane in relation to fluid compartments?

Separates intracellular and extracellular fluid Signup and view all the answers

Which of the following ions is NOT a principal anion in extracellular fluid?

Sulfate (SO42-) Signup and view all the answers

What is the name of the fluid compartment that includes fluid in synovial, peritoneal, and pleural cavities?

Transcellular fluid Signup and view all the answers

Which of the following electrolytes is NOT a principal intracellular electrolyte?

Sodium (Na+) Signup and view all the answers

What is the term for the non-cellular component of blood?

Plasma volume Signup and view all the answers

Which of the following is a function of the regulation of sodium and chloride?

Regulating fluid balance Signup and view all the answers

What percentage of extracellular fluid is composed of interstitial fluid?

3/4 Signup and view all the answers

What is a common cause of edema related to heart failure, renal failure, and pregnancy?

Hypervolemia Signup and view all the answers

What is the main function of plasma proteins in the capillary?

To increase plasma osmotic pressure Signup and view all the answers

What is a possible consequence of kidney disease on plasma proteins?

Decreased protein levels Signup and view all the answers

What impairs protein synthesis in patients with malnutrition or liver disease?

Impaired liver function Signup and view all the answers

What is the primary cause of increased capillary permeability?

Histamine release Signup and view all the answers

What is a common result of increased capillary permeability?

Localized edema Signup and view all the answers

What can cause localized edema due to obstruction of the lymphatic circulation?

All of the above Signup and view all the answers

What happens to excess fluid and protein in the interstitium due to lymphatic obstruction?

They accumulate in the interstitium Signup and view all the answers

What is a common consequence of edema due to increased hydrostatic pressure?

Increased fluid movement out of the vascular bed Signup and view all the answers

What is a possible cause of decreased plasma osmotic pressure?

Decreased albumin levels Signup and view all the answers

What percent of the ECF is typically made up of the transcellular compartment?

1% Signup and view all the answers

What is the term for when the transcellular compartment enlarges significantly?

Third spacing Signup and view all the answers

Why is fluid in the transcellular space not readily available for exchange with the rest of the ECF?

Because it is not in equilibrium with the rest of the ECF Signup and view all the answers

What is edema characterized by?

An excessive amount of fluid in the interstitial compartment Signup and view all the answers

What is an example of localized edema?

Facial edema Signup and view all the answers

What are the four general causes of edema?

Increased capillary hydrostatic pressure, decreased capillary oncotic pressure, increased capillary permeability, and lymph obstruction Signup and view all the answers

What is the result of increased capillary hydrostatic pressure on fluid movement?

Fluid is forced out of the capillaries into the tissues Signup and view all the answers

What is an example of edema that can interfere with respiratory function?

Pulmonary edema Signup and view all the answers

What would be the result of hypervolemia on capillary hydrostatic pressure?

Increased capillary hydrostatic pressure Signup and view all the answers

What is the term for edema that is generalized throughout the body?

Anasarca Signup and view all the answers

Study Notes

Water in the Body

Water is a major component of the body, found within and outside cells, and is essential for homeostasis.
Water is the medium for metabolic reactions and processes.

Fluid Distribution

Total Body Water (TBW) is distributed into two compartments: Intracellular Fluid (ICF) and Extracellular Fluid (ECF).
ICF consists of fluid inside cells, making up ~2/3 of TBW, and is separated from ECF by the cell membrane.
ECF makes up ~1/3 of TBW and is divided into two components: plasma volume (intravascular fluid) and interstitial fluid (extravascular fluid).

Electrolytes

Potassium (K+) is the principal cation in ICF.
Phosphates and proteins are the principal anions in ICF.
Sodium (Na+) is the principal cation in ECF.
Chloride (Cl-) and bicarbonate (HCO3-) are the principal anions in ECF.

Transcellular Compartment

The transcellular compartment is a minor subdivision of ECF, making up ~1% of ECF.
It includes fluid in synovial, peritoneal, pleural, pericardial, intraocular, and CSF.
This compartment can increase significantly in conditions such as ascites.

Edema

Edema refers to an excessive amount of fluid in the interstitial compartment, causing swelling or enlargement of tissues.
Edema can be localized or generalized throughout the body.
There are four general causes of edema:
- Increased capillary hydrostatic pressure
- Decreased capillary oncotic pressure
- Increased capillary permeability
- Lymph obstruction

Causes of Edema

Increased capillary hydrostatic pressure forces fluid out of capillaries into tissues, contributing to edema.
Decreased capillary oncotic pressure due to a loss of plasma proteins (mainly albumin) allows more fluid to leave the capillary and enter the interstitium.
Increased capillary permeability usually causes localized edema and may result from an inflammatory response or infection.
Lymph obstruction causes localized edema by preventing excessive fluid and protein from being returned to the general circulation.

Studying That Suits You

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

Description

Learn about the importance of water in the human body, its distribution in compartments, and the roles of intracellular and extracellular fluids in maintaining homeostasis.