Gradients in Physiology: Sodium and Potassium

Flashcards based on lecture notes about gradients in physiology, specifically sodium and potassium ion concentrations and their movements across cell membranes.

What are gradients in physiology?

The basis for many chemical reactions in the body, involving substances moving from areas of high concentration to low concentration.

What is the role of the cell membrane (plasma membrane)?

A barrier that is selectively permeable, allowing certain substances to pass in and out of the cell.

What does concentration mean in the context of physiology?

It refers to the amount of a substance (molecule or ion) relative to the amount of water in a given space (either extracellular or intracellular fluid).

What is the concentration gradient of sodium (Na+)?

Na+; typically much higher outside the cell (in the extracellular fluid) than inside the cell (in the intracellular fluid).

What is diffusion?

The passive movement of a substance (e.g., sodium) from an area of high concentration to an area of low concentration.

What is the concentration gradient of potassium (K+)?

K+; typically much higher inside the cell than outside the cell.

What is the typical electrical charge distribution in a resting cell?

Inside of a resting cell tends to be negative, and the exterior tends to be positive.

What is an ion?

A charged atom, either positive (cation) or negative (anion).

What is an electrochemical gradient?

Movement of ions influenced by both concentration (chemical) and electrical gradients.

What is a cation?

A positively charged ion, such as sodium (Na+) or potassium (K+).

What is an anion?

A negatively charged ion, such as chloride (Cl-).