Veterinary Physiology-III

INTRODUCTION

• Organs and sytems in the body need to communicate with each other so that homeostasis is maintained.
• Cells use either chemical and/ or electrical signals to communicate with each other.

Cell-to-cell communication

• Cells can communicate by direct transfer of electrical or chemical signals through gap junctions (proteins side-by-side with a hole down the middle) that connect cells to each other.
• Chemical signals are three types
• Autocrines are chemicals that are produced by a cell and act on the same cell
• Paracrines are chemicals that are produced by one cell and act on nearby cells by diffusing locally through the ECF
• Endocrine substances are chemicals that travel long distances through blood