Chapter 46: Chemical Signals in Animals

Flashcards covering key vocabulary and concepts from the lecture notes on chemical signals in animals.

Endocrine System

Secretes hormones that coordinate slower but longer-acting responses in animals.

Hormones

Chemical signals secreted into the circulatory system that communicate regulatory messages to target cells.

Target Cells

Cells that can respond to a particular hormone.

Pheromones

Chemical signals produced by one individual that affect the behavior of another individual of the same species (usually volatiles).

Steroid Hormones

Lipid soluble hormones synthesized from cholesterol that bind to receptors inside the target cell.

Peptide and Polypeptide Hormones

Hormones that are not lipid soluble and bind to receptors on the surface of the target cell.

Amino Acid Derivative Hormones

Hormones that are mostly not lipid soluble and bind to receptors on the surface of the target cell.

Thyroid Hormone (T3)

Controls metamorphosis in amphibians.

Growth Hormone (GH)

Regulates growth factors that control the cell cycle in mammals; HG declines with age, causes many “aging” effects.

Antagonistic Hormones

Pairs of hormones (like insulin and glucagon) that have opposing effects and help maintain homeostasis.

Erythropoietin (EPO)

Stimulates the production of red blood cells when blood oxygen levels fall.

Hypothalamus

Receives information from the CNS and initiates a response, coordinating the nervous and endocrine systems; makes hormones that are stored and secreted by the posterior pituitary gland.

Anterior Pituitary Gland

Makes and releases hormones under control of the hypothalamus.

Epinephrine (Adrenaline)

A hormone released during short-term stress by the 'fight or flight' response of sympathetic nerves.

Cortisol

A hormone involved in long-term stress responses; ensures continued glucose availability but can lead to loss of muscle mass, immune suppression, and insulin resistance.

Xenoestrogens

Environmental pollutants recognized by hormone receptors, often estrogen receptors (e.g., phthalates, PCBs, parabens).

Endocrine Disruptors

Substances that can cause numerous health issues in humans and wildlife by interfering with the endocrine system.