Endocrine

Endocrine System Study Guide

Endocrine System: Collection of glands and cells that produce hormones.

Hormone: Chemical messenger that travels in the bloodstream to a target cell.

Hormone Types:

Amino acid-based: Hydrophilic, bind to extracellular receptors, use second messenger systems.

Steroid: Hydrophobic, bind to intracellular receptors, trigger protein synthesis.

Hormonal Release:

Neural: Triggered by nervous system.

Hormonal: Triggered by other hormones.

Humoral: Triggered by blood chemistry changes.

Regulation: Negative feedback.

Hormone elimination: Excretion, metabolism, active transport.

Hypothalamus: Releases inhibiting/releasing hormones, controls pituitary.

Pituitary Gland:

Anterior: Produces hormones (TSH, ACTH, FSH, LH, GH, PRL).

Posterior: Stores/releases ADH and oxytocin.

Thyroid:

Thyroid hormone: Increases metabolism.

Calcitonin: Lowers blood calcium.

Parathyroid:

PTH: Raises blood calcium.

Pancreas:

Insulin: Lowers blood glucose.

Glucagon: Raises blood glucose.

Adrenal Glands:

Cortex: Aldosterone (Na+ balance), Cortisol (stress, glucose).

Medulla: Epinephrine (fight or flight).

Pineal: Melatonin (sleep).

Gonads:

Testes: Testosterone.

Ovaries: Estrogen and progesterone.