Endocrine System Overview

These flashcards cover key vocabulary and concepts related to the endocrine system, including definitions of hormones, glands, and their functions.

Endocrine Glands

Glands that secrete hormones directly into the bloodstream without the use of ducts.

Hormones

Chemical messengers that travel through the bloodstream and affect target cells with specific receptors.

Target Cells

Cells that have receptors for a specific hormone and are affected by that hormone.

Negative Feedback

A regulatory mechanism in which a change in a physiological variable triggers a response that counteracts the initial change.

Positive Feedback

A process that enhances or accelerates processes already in motion, often leading to an increased output.

Steroid Hormones

Lipid-soluble hormones derived from cholesterol that easily pass through cell membranes.

Water-soluble Hormones

Hormones that cannot freely pass through the cell membrane and do not require transport proteins in the blood.

Second Messenger System

A method by which water-soluble hormones act on target cells through a series of internal signaling processes.

Thyroid Hormones

Hormones produced by the thyroid gland that regulate metabolism, including T3 and T4.

Calcitonin

A hormone secreted by the thyroid that lowers blood calcium levels by inhibiting osteoclast activity.

Parathyroid Hormone (PTH)

A hormone secreted by the parathyroid glands that increases blood calcium levels by stimulating osteoclasts.

Glucagon

A hormone secreted by alpha cells of the pancreas that raises blood glucose levels.

Insulin

A hormone secreted by beta cells of the pancreas that lowers blood glucose levels by facilitating cellular uptake.

Adrenal Cortex

The outer region of the adrenal glands that produces glucocorticoids, mineralocorticoids, and sex hormones.

Atrial Natriuretic Peptide (ANP)

A hormone produced by the heart that helps regulate blood pressure by promoting sodium and water excretion.

Erythropoietin (EPO)

A hormone produced by the kidneys that stimulates the production of red blood cells.

Leptin

A hormone produced by adipose tissue that helps regulate energy balance by inhibiting hunger.

Hypothalamus

An area of the brain that regulates the endocrine system by controlling the release of hormones from the pituitary gland.

Anterior Pituitary

The glandular part of the pituitary that secretes hormones like growth hormone, ACTH, and TSH.

Posterior Pituitary

The part of the pituitary that stores and releases hormones like oxytocin and ADH produced by the hypothalamus.