Human Physiology: Interactions Between Cells and Their Environment

These flashcards cover key concepts regarding cell interactions with their environment, relevant transport mechanisms, body fluid distribution, and essential physiological processes.

What does the extracellular environment include?

Everything located outside the cells.

What is the percentage of body fluids that is found in the extracellular compartment?

33%.

What are the two main types of molecule transport across the plasma membrane?

Passive transport and active transport.

What is osmosis?

The diffusion of water across a semipermeable membrane.

What is the osmotic pressure?

The force surrounding a cell required to stop osmosis.

What is tonicity?

The ability of a solution to affect cell volume based on osmolarity.

What is facilitated diffusion?

Movement of molecules from high to low concentration using specific carrier proteins without ATP.

What is the role of the Na+/K+ pump?

To pump 3 Na+ out and 2 K+ into the cell, maintaining electrochemical gradients.

What distinguishes primary active transport from secondary active transport?

Primary active transport directly uses ATP, while secondary uses energy from the electrochemical gradient established by primary transport.

What is the function of aquaporins in osmosis?

Aquaporins facilitate the passage of water across the membrane.