Chemical Signals in Animals: Endocrine System

Flashcards covering key concepts from the endocrine system and chemical signaling in animals.

What are pheromones?

Chemical signals released to the environment to communicate with other organisms.

What is autocrine signaling?

Self-signaling where a cell secretes a chemical signal that stimulates receptors on its own membrane.

What is paracrine signaling?

A signaling process where a cell releases a chemical signal to communicate with neighboring and nearby cells.

What is endocrine signaling?

A type of signaling where hormones are released into the bloodstream to signal distant cells.

Define synaptic signaling.

Signaling where neurons carry electric signals translated into chemical signals, released to other cells.

What are neurotransmitters?

Chemicals that traverse synapses between neurons to carry signals between them.

What is a hormone?

A signaling molecule produced in glands and secreted into the bloodstream.

What are the three classes of hormone structure?

Polypeptide hormones, amine hormones (derived from amino acids), and steroid hormones (derived from cholesterol).

What is the role of intracellular receptors?

Receptors found inside of cells that modify gene expression by acting as transcription factors.

What is the effect of water-soluble hormones?

They bind to cell-surface receptors and activate signal transduction pathways to communicate within the cell.

What is the significance of the hypothalamus in the endocrine system?

It interacts with the pituitary gland and acts as a homeostatic center for regulatory systems.

What hormones does the anterior pituitary secrete?

Tropic and direct hormones, including FSH, LH, ACTH, TSH, prolactin, and GH.

What is the function of thyroid hormones?

They regulate metabolic rate and play a role in calcium homeostasis.

What is erythropoietin?

A hormone secreted by the kidneys to stimulate erythrocyte production in bone marrow.

What are gonads?

Endocrine glands that produce gametes, regulated by LH and FSH.

Define leptin and ghrelin.

Leptin inhibits appetite, produced by adipocytes; ghrelin stimulates appetite.

What is the hypothalamic-pituitary-adrenal (HPA) axis?

A negative feedback loop that controls stress levels involving the secretion of CRH, ACTH, and cortisol.