Overview
This lecture covers how substances move in and out of cells, focusing on the cell membrane's structure and its role in maintaining homeostasis between intracellular and extracellular fluid compartments.
Review of Homeostasis and Fluid Compartments
- Homeostasis is the maintenance of a relatively constant internal environment.
- The internal environment is defined as the extracellular fluid in the body.
- Fluid compartments in the human body include intracellular fluid (inside cells) and extracellular fluid (outside cells).
The Cell Membrane as a Barrier
- The cell membrane is the structure that separates intracellular fluid from extracellular fluid.
- It mediates movement, communication, and actions between fluid compartments.
- The cell membrane controls what enters and exits the cell, maintaining essential concentration gradients.
Introduction to Membrane Function
- The cell membrane selectively allows substances to enter or leave the cell.
- It enables investment of energy to import materials or establish concentration gradients for transport.
- Proper membrane function is vital to support homeostasis and cell survival.
Key Terms & Definitions
- Homeostasis — maintenance of a stable internal environment in the body.
- Intracellular Fluid — fluid inside the cell.
- Extracellular Fluid — fluid outside the cell.
- Cell Membrane — the barrier that separates and regulates movement between intracellular and extracellular fluid.
Action Items / Next Steps
- Watch the x Vivo cell animation video to visualize cellular processes.