Signaling Molecules and the Endocrine System

Flashcards covering key concepts related to signaling molecules and the endocrine system, including definitions and explanations.

Signaling Molecules

Chemical substances released by one cell that interact with another cell to cause a reaction.

Endocrine System

A system of glands that produce hormones carried by blood to target cells.

Hormones

Signaling molecules produced by the endocrine system, primarily transported via blood.

Neurotransmitters

Signaling molecules in the nervous system that transmit signals from neurons to target cells.

Peptides and Proteins

Signaling molecules composed of amino acid chains that are hydrophilic and water soluble.

Steroids

Lipid molecules with four hydrocarbon rings, typically hydrophobic and require carrier proteins for transport.

Catecholamines

A type of amine signaling molecule produced by the adrenal gland, behaving similarly to peptides.

Thyroid Hormones

A type of amine signaling molecule that behaves similarly to steroids.

Tropic Hormones

Hormones that stimulate the release of other hormones, acting as a stimulus in endocrine reflexes.

Negative Feedback Mechanism

A regulatory mechanism where the result of endocrine activity inhibits subsequent activity to maintain homeostasis.

Positive Feedback Mechanism

A self-reinforcing mechanism that drives the stimulus level away from normal homeostasis.

Feedback Mechanisms

Regulatory processes in the endocrine system that involve the influence of activity results on subsequent activities.

Hypothalamus

A brain region that controls the anterior pituitary gland and produces hormones for circulation.

Pituitary Gland

A gland located below the hypothalamus that regulates various hormonal functions.

Adrenal Gland

A gland divided into the cortex and medulla, with roles in metabolism and the fight-or-flight response.

Islet Cells

Cells in the pancreas responsible for regulating blood glucose levels.

Gonads

Reproductive glands responsible for producing sex cells and sex-related hormones.

Testis

The male gonad that regulates sperm production and male secondary sexual characteristics.

Ovary

The female gonad that regulates egg production and female secondary sexual characteristics.