Chemical Messengers

These flashcards cover key vocabulary and concepts related to the communication mechanisms in human cells, focusing on chemical messengers and their classifications.

Intercellular Communication

Communication that occurs between two or more cells, either nearby or at a distance.

Chemical Messengers

Substances used by cells to communicate with other cells, including hormones, neurotransmitters, and paracrines.

Direct Communication

When cells communicate directly with each other, often through structures like gap junctions.

Indirect Communication

Occurs when one cell uses a chemical or electrical signal to communicate with another cell.

Target Cell

The cell that receives a chemical messenger.

Ligands

Molecules that bind to proteins and facilitate communication between cells.

Paracrines

Chemical messengers that communicate with neighboring cells, typically by simple diffusion.

Autocrines

A specific type of paracrine that acts on the same cell that secretes it, regulating its own secretions.

Neurotransmitter

Chemicals released by neurons into interstitial fluid to communicate with target cells.

Hormones

Chemical messengers released by endocrine glands, traveling through the bloodstream to target cells.

Receptor Agonist

A ligand that binds to a receptor and induces a response.

Receptor Antagonist

A ligand that binds to a receptor but blocks a response.

Signal Transduction

The process by which chemical messengers transmit their signals by binding to target cell receptors.

Lipophilic Messenger

A type of messenger that can easily pass through the plasma membrane and bind to intracellular receptors.

Lipophobic Messenger

A type of messenger that cannot easily pass through the plasma membrane and binds to surface receptors.

Channel-Linked Receptors

Receptors that, upon binding with a messenger, open an ion channel to allow ions to flow across the membrane.

Enzyme-Linked Receptors

Receptors that function as both receptors and enzymes, becoming activated upon binding of a messenger.

G-Linked Receptors

Receptors that activate G-proteins, leading to a variety of cellular responses.

Half Life

The amount of time it takes for half of a hormone in the blood to be degraded.