Hormones and Endocrine Signaling (Ch. 32.2)

Vocabulary flashcards covering the major concepts of animal chemical signals, endocrine signaling, hormone groups, and the hypothalamic-pituitary axis.

Cell-to-cell communication

The signaling between cells to coordinate growth, development, and homeostasis in animals.

Animal chemical signals

Signals such as hormones, paracrines, autocrines, and neurohormones used for intercellular communication.

Hormone (endocrine)

A chemical signal released by endocrine cells into the bloodstream to act on distant target cells.

Target cell

A cell that has receptors for a specific hormone and responds to it.

Capillary near secreting cell

A small blood vessel that collects hormones released by endocrine cells for transport in blood.

Endocrine cell

A cell that releases hormones into the bloodstream to reach distant targets.

Receptor

A molecule on or in a cell that binds a hormone to elicit a response.

Paracrine

Signaling where the secreted molecule affects nearby cells in the same tissue.

Autocrine

Signaling where the secreted molecule acts on the secreting cell itself.

Mast cell histamine (paracrine example)

Histamine released by mast cells that acts locally in response to allergens.

Neurohormone

A hormone produced by a neuron and released into the bloodstream to affect distant targets.

Neurotransmitter

A chemical signal released by a neuron to communicate with an adjacent cell at a synapse.

Endocrine system

Glands and organs that secrete hormones into the bloodstream to regulate body functions.

Hypothalamus

Brain region that links nervous and endocrine systems and regulates the pituitary.

Pituitary gland

The master gland that releases hormones influencing other glands; consists of posterior and anterior parts.

Posterior pituitary

Part of the pituitary that stores and releases hypothalamic neurohormones (ADH and oxytocin).

ADH (vasopressin)

Antidiuretic hormone; promotes water conservation and helps regulate blood pressure.

Oxytocin

Hormone involved in birth (uterine contractions) and lactation; also influences social bonding.

Anterior pituitary

Gland that receives hypothalamic neurohormones via portal vessels and releases several hormones.

Hypothalamic portal system

Portal vessels that transport hypothalamic neurohormones to the anterior pituitary.

LH (Luteinizing Hormone)

An anterior pituitary gonadotropin that triggers ovulation and supports testosterone production.

FSH (Follicle-Stimulating Hormone)

An anterior pituitary gonadotropin that stimulates ovarian follicle development and spermatogenesis.

TSH (Thyroid-Stimulating Hormone)

An anterior pituitary hormone that stimulates the thyroid to produce thyroid hormones.

ACTH (Adrenocorticotropic Hormone)

An anterior pituitary hormone that stimulates the adrenal cortex to release cortisol.

GH (Growth Hormone)

Anterior pituitary hormone that stimulates growth and affects metabolism.

Prolactin

Anterior pituitary hormone that promotes milk production in the mammaries.

Tropic hormones

Hormones from the anterior pituitary that stimulate other endocrine glands to release their hormones.

Gonadotropins

LH and FSH; hormones that regulate the activity of the gonads.

Androgens

Male sex hormones (e.g., testosterone) that direct male sexual development and characteristics.

Gonadotropins (LH/FSH)

Hormones that stimulate the gonads to produce sex steroids and gametes.

Steroid hormone

Lipid-soluble hormones derived from cholesterol (e.g., testosterone).

Peptide hormone

Hydrophilic hormones composed of short amino acid chains (≥2).

Protein hormone

Hydrophilic hormones with long amino acid chains (≥50).

Amine hormone

Hormones derived from a single amino acid (tyrosine); can be water- or lipid-soluble.

Testosterone

A lipid-soluble androgen steroid hormone; drives male development and characteristics.

Epinephrine (adrenaline)

A fight-or-flight hormone that prepares the body for rapid action.

Fight-or-flight response

Physiological changes triggered by stress hormones like epinephrine.

Portal vessels

Blood vessels that connect the hypothalamus to the anterior pituitary, delivering neurohormones.