Question

bio - 202 topic 1: cellular communication and endocrine system physiology
practice it
what is autocrine signaling?
a type of signaling that involves the release of hormones into the bloodstream
similar to paracrine signaling, but the signal molecule acts on the same cell that released it
a type of signaling that occurs between adjacent cells
a type of signaling where the signal molecule acts on cells in a different tissue
a type of signaling that occurs between distant cells

Explanation:

Autocrine signaling is a form of cell - to - cell communication. In autocrine signaling, the cell that releases the signaling molecule (such as a cytokine or growth factor) also has the receptor for that molecule on its surface. So, the signal acts on the same cell that released it.
Paracrine signaling is when a cell releases a signal that acts on nearby cells. Endocrine signaling involves hormones being released into the bloodstream to act on distant cells.

• Option 1: This describes endocrine signaling, not autocrine.
• Option 2: Correct. Autocrine is similar to paracrine (local signaling) but acts on the same cell.
• Option 3: This is more characteristic of paracrine or juxtacrine (direct cell - to - cell contact) signaling, not specifically autocrine.
• Option 4: This is not autocrine. Autocrine acts on the same cell, not a different tissue.
• Option 5: This is endocrine signaling.

Answer:

Similar to paracrine signaling, but the signal molecule acts on the same cell that released it.