Cellular Fluids and Acid-Base Homeostasis

Flashcards covering cellular fluid categories, fluid movement mechanisms, metabolic water balance, and chemical acid-base regulation.

Intracellular fluid (ICF)

Fluid located inside of your cells; it makes up most of our body fluid.

Extracellular fluid (ECF)

Fluid located outside of your cells, including interstitial fluid, plasma, lymph, and transcellular fluid.

Interstitial fluid

Fluid located in the tissue.

Edema

A buildup of fluid in the tissue caused by an increase or excessive percentage of interstitial fluid.

Plasma

The fluid or liquid component of blood, including noncellular components like serum.

Serum

The clear, fluid part of blood that remains after the cellular components are separated in a centrifuge.

Lymph

Lymphatic fluid that flows through lymph nodes and lymphatic vessels.

Transcellular fluid

A category of extracellular fluid for everything else that does not fit into the interstitial, plasma, or lymph categories.

Tenting

A physical sign of dehydration where the skin stays up when pulled rather than snapping back into place.

Diffusion

The movement of particles from an area of high concentration to an area of low concentration.

Osmosis

The movement of water from an area of high concentration to an area of low concentration.

Osmolarity

The concentration of particles, specifically electrolytes, in a solution.

Homeostasis

The process of creating balance within the body's internal environment.

Lysis

The destruction of a cell, which can be caused by extreme shrinking.

Average Daily Fluid Balance

The amount of water taken into the body should equal the amount put out, approximately $2,500\,mL$ (or $2.5\,L$).

Water intoxication

Also known as internal drowning; it occurs when water is consumed so rapidly that kidneys cannot excrete it, causing cells to swell and burst.

Hypothalamus

The region of the brain that houses the thirst center and coordinates mechanisms to handle dehydration.

Antidiuretic hormone (ADH)

A hormone secreted by the posterior pituitary that tells the kidneys to retain water and decrease urine output.

Volume depletion

A fluid deficiency where water and sodium are lost equitably, such as in hemorrhage, vomiting, or diarrhea.

Dehydration

A fluid deficiency where more water is being lost than sodium.

Fluid Loss Pathway (Sweat)

The movement of fluid from the intracellular space to the interstitial space, then to the plasma, and finally out through the pores.

Normal Blood pH Range

$7.35$ to $7.45$.

Chemical buffers

Substances such as bicarbonate, phosphate, and proteins that bind to acids to neutralize pH and prevent sudden changes.

Bicarbonate ($HCO_3^-$)

The primary metabolic chemical buffer utilized in arterial blood gases (ABGs) to bind to acids and bring up pH.

Chemoreceptor

A receptor that detects changes in chemical balance, specifically detecting when $CO_2$ is high and pH is low.