Endocrine System Study Guide

These flashcards cover key vocabulary terms and concepts related to the endocrine system and its functions.

Endocrine System

A system that regulates bodily functions by producing and secreting hormones.

Homeostasis

The maintenance of stable internal conditions in the body, regulated by the endocrine and nervous systems.

Lipid-Soluble Hormones

Hormones derived from cholesterol or amino acids that pass through cell membranes easily, like cortisol and estrogen.

Water-Soluble Hormones

Hormones that cannot pass through cell membranes and require surface receptors, such as insulin and glucagon.

Negative Feedback

A control mechanism where a high level of a substance leads to decreased secretion of a hormone, like insulin regulating blood glucose.

Positive Feedback

A control mechanism where an initial stimulus leads to an increased output of a hormone, like oxytocin enhancing contractions during childbirth.

Hypothalamus

The command center that links the nervous and endocrine systems, producing releasing and inhibiting hormones.

TRH (Thyrotropin-Releasing Hormone)

A hypothalamic hormone that stimulates the release of TSH from the pituitary gland.

GH (Growth Hormone)

A hormone that stimulates growth and metabolism; hyposecretion can lead to dwarfism, while hypersecretion can cause gigantism.

Hypothyroidism

A condition caused by thyroid hormone deficiency leading to symptoms like weight gain and fatigue.

Hyperthyroidism

A condition caused by excessive thyroid hormones leading to symptoms like weight loss and rapid heart rate.

Cortisol

A hormone that regulates stress and metabolism; hyposecretion may lead to Addison's disease, while hypersecretion can cause Cushing's syndrome.

ADH (Antidiuretic Hormone)

A hormone that helps retain water in the kidneys; hyposecretion leads to diabetes insipidus, while hypersecretion causes water retention.

Fight or Flight

A short-term stress response mediated by the sympathetic nervous system involving the release of epinephrine and norepinephrine.

HPA Axis

The long-term stress response pathway involving the hypothalamus, pituitary, and adrenal cortex, leading to cortisol release.

Nervous System vs. Endocrine System

The nervous system sends rapid electrical signals while the endocrine system uses slower hormonal signals.