Endocrine System Flashcards

Vocabulary flashcards for the Endocrine System lecture notes.

Endocrine System

Glands, tissues, and cells that secrete hormones.

Endocrinology

The study of the endocrine system and the diagnosis and treatment of its disorders.

Endocrine glands

Organs that are traditional sources of hormones.

Hormones

Chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ, often a considerable distance away.

Target Cells

Cells that have receptors for a specific hormone, allowing the hormone to alter the cell's metabolism.

Steroid Hormones

Hormones derived from cholesterol, secreted by gonads and the adrenal cortex.

Amine Hormones

Hormones derived from amino acids, secreted by adrenal medulla, pineal, and thyroid glands.

Peptide and Protein Hormones

Hormones consisting of chains of amino acids, secreted by the pituitary and hypothalamus, stored in secretory vesicles until needed and released by exocytosis.

Hydrophilic Hormones

Water-soluble hormones that use cell membrane receptors to initiate a second-messenger cascade.

Hydrophobic Hormones

Lipid-soluble hormones that use intracellular receptors and target DNA for gene transcription.

Up-regulation

Increase in receptor number on a target cell, increasing sensitivity to a hormone.

Down-regulation

Decrease in receptor number on a target cell, decreasing sensitivity to a hormone; happens with long-term exposure to high hormone concentrations.

Synergistic Effects

Hormone interactions where two or more hormones act together to produce a stronger effect.

Permissive Effects

Hormone interactions where one hormone allows another hormone to be more effective.

Antagonistic Effects

Hormone interactions where one hormone opposes the action of another.

Metabolic Clearance Rate (MCR)

Rate of hormone removal from the blood.

Half-life

Time required to clear 50% of hormone from the blood.

Hypothalamus

A section of the brain above the pituitary gland that controls the pituitary gland with releasing and inhibiting hormones.

Pituitary Gland

Considered a master endocrine gland, controls other endocrine glands with tropic hormones; suspended from hypothalamus via infundibulum.

ADH (Antidiuretic Hormone)

A hormone produced by the hypothalamus and secreted by the posterior pituitary; targets kidneys for increased water retention and decreased urine production; also called vasopressin.

OT (Oxytocin)

A hormone produced by the hypothalamus and secreted by the posterior pituitary; promotes labor contractions and lactation; promotes emotional bonding.

Neuroendocrine Reflex

Hormone release in response to nervous system signals.

ACTH (Adrenocorticotropic Hormone)

Anterior pituitary hormone that regulates response to stress, stimulates adrenal cortex, corticosteroids regulate glucose, fat, and protein metabolism.

TSH (Thyroid Stimulating Hormone)

Anterior pituitary hormone that stimulates the growth of the thyroid and the secretion of TH.

FSH (Follicle Stimulating Hormone)

Anterior pituitary hormone that stimulates production of egg or sperm cells.

LH (Luteinizing Hormone)

Anterior pituitary hormone that mainly stimulates hormone production; stimulates ovulation and corpus luteum to secrete progesterone and estrogen in females, and stimulates interstitial cells of testes to secrete testosterone in males.

PRL (Prolactin)

Anterior pituitary hormones that stimulates milk synthesis after delivery in females and increases LH sensitivity and testosterone secretion in males.

GH (Growth Hormone)

Anterior pituitary hormone that promotes tissue growth.