Body Fluid and Electrolyte Balance

These vocabulary flashcards cover body fluid compartments, the mechanisms of fluid movement, edema development theories, and normal electrolyte ranges and imbalances based on lecture material.

Intracellular Compartment

Fluid found inside our cells, making up roughly $40\%$ of our body weight.

Extracellular Compartment

Fluid found outside our cells, making up roughly $20\%$ of our body weight, which includes interstitial fluid and plasma.

Interstitial fluid

The fluid found around or in-between cells, representing $15\%$ of body weight.

Plasma

The liquid part of our blood, representing $5\%$ of body weight, with a typical volume of about $3.5\,L$.

Blood Alcohol Concentration (BAC)

A measurement where a person is considered drunk at $0.08\%$, meaning $8\,grams$ of alcohol per $100\,mL$ of blood.

Aldosterone

The final hormone in the renin-Angiotensin-Aldosterone pathway ($RAAS$) that causes the kidneys to retain salt and water to increase blood volume and pressure.

Natriuretic Peptide

Hormones including Atrial ($ANP$) and Brain ($BNP$) that promote sodium and water excretion to lower blood volume and blood pressure.

Antidiuretic Hormone (ADH)

Released by the posterior pituitary, this hormone causes the kidneys to retain more water by reabsorbing more kidney filtrate, resulting in concentrated urine.

Capillary Hydrostatic Pressure (CHP)

The pressure of blood in capillaries that pushes fluid out to the tissues.

Interstitial Fluid Hydrostatic Fluid Pressure (IFHP)

The pressure exerted by the interstitial fluid that pushes fluid back into the capillaries.

Blood (Plasma) oncotic pressure (BOP)

Also known as Colloidal Pressure, it is the pressure caused by plasma proteins pulling fluid back into the capillaries.

Interstitial Fluid Osmotic Pressure (IFOP)

The pressure caused by proteins and solutes in the tissues pulling fluid out from the capillaries into the tissues.

Filtration

The process of fluids moving out to tissues, determined by the sum of $CHP + IFOP$.

Absorption

The process of fluid moving in from tissues to the capillaries, determined by the sum of $IFHP + BOP$.

Transmural Hydrostatic Pressure

The net difference between Capillary Hydrostatic Pressure ($CHP$) and Interstitial Fluid Hydrostatic Fluid Pressure ($IFHP$).

Edema

The abnormal accumulation of fluid in the interstitial space, which can disrupt cells and lead to pressure sores or ulcers.

Varicose veins

Twisted, swollen, and enlarged veins caused by faulty venous valves, leading to blood pooling.

Pitting Edema

A characteristic of swelling where pressing the area leaves a dent (pit) for a period, due to an increased amount of protein-rich fluid.

Ascites

The accumulation of fluid in the peritoneal cavity of the abdomen, often associated with liver cirrhosis and portal hypertension.

Underfilling Theory

A development of edema where protein loss lowers $BOP$, causing fluid to be pulled out of vessels and triggering the kidneys to retain salt and water.

Overfilling Theory

A development of edema where a faulty kidney holds too much sodium and water, leading to total fluid overload.

Peripheral Arterial Vasodilation Theory

A development of edema where widespread arterial dilation leads the kidneys to retain salt and water because the system perceives a lack of circulating blood.

Dehydration

A state of low fluid with high sodium concentration ($hypernatremia$) and high water loss in urine.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)

A condition characterized by excessive $ADH$, leading to water retention, high fluid volume, and low sodium ($hyponatremia$).

Diabetes Insipidus

A condition caused by $ADH$ deficiency or resistance, leading to the excretion of large amounts of dilute urine and $hypernatremia$.

Sodium ($Na^+$)

An electrolyte with a normal range of $135-145$, where imbalances can cause confusion, edema, or a dry sticky tongue.

Potassium ($K^+$)

An electrolyte with a normal range of $3.5-5.0$, where hyperkalemia is treated with Kayexalate and monitors for cardiac arrhythmias.

Chloride ($Cl^-$)

An electrolyte with a normal range of $97-107$, where hypochloremia can lead to hyperexcitability of muscles and tetany.

Magnesium ($Mg^{2+}$)

An electrolyte with a normal range of $1.3-2.3$ that calms neuromuscular activity; high levels can lead to respiratory depression or coma.

Calcium ($Ca^{2+}$)

An electrolyte with a normal range of $8.6-10.2$ necessary for bone and heart health; low levels may cause numbness or tingling of fingers.

Phosphate ($PO_4^{3-}$)

An electrolyte with a normal range of $2.5-4.5$ that promotes energy storage and metabolism of carbohydrates, protein, and fat.