Question

For a cell to respond to a ligand's release from a neighboring cell where the ligand diffuses directly from one cell to another is called ______ communication.

A) Paracrine
B) Autocrine
C) Juxtacrine
D) Endocrine

Answer 1

The correct answer is A) Paracrine communication. Paracrine signaling involves ligands that diffuse locally between adjacent cells to elicit a quick and localized response.

Step-by-step explanation:

For a cell to respond to a ligand released from a neighboring cell, where the ligand diffuses directly from one cell to another, is called paracrine communication. Paracrine signaling is a form of chemical signaling where signals act locally between cells that are close together. The ligands involved in paracrine signaling move by diffusion through the extracellular matrix and typically elicit quick responses that are short-lived. Paracrine signals are designed to act on nearby cells and are quickly degraded by enzymes or removed by neighboring cells to ensure that the response stays localized and the concentration gradient for the signal is reestablished.

In contrast, autocrine signaling refers to signals that act on the signaling cell itself or neighboring cells of the same type, juxtacrine signaling involves direct contact through gap junctions, and endocrine signaling involves ligands that travel through the circulatory system to act on distant cells.