Chapter 21

Endocrine System

What is the Endocrine System?
The endocrine system sends hormones—chemical signals—through the bloodstream to target cells—the cells the hormones selectively…
Intracellular Hormone Receptors
21.2: Intracellular Hormone Receptors
Lipid-soluble hormones diffuse across the plasma and nuclear membrane of target cells to bind to their specific intracellular receptors. These…
Cell-surface Signaling
21.3: Cell-surface Signaling
Hormones—or any molecule that binds to a receptor, known as a ligand—that are lipid-insoluble (water-soluble) are not able to diffuse…
Feedback Loops
21.4: Feedback Loops
In most cases, excessive hormone production is prevented by negative feedback—a loop that starts with a stimulus inducing the release of a…
Hypothalamic-Pituitary Axis
21.5: Hypothalamic-Pituitary Axis
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA)…
Biology: A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System
21.7: Biology: A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System
Endogenous and artificial glucocorticoids are used to treat inflammation, but cause severe side effects when used long-term. This article…
Neuroscience: Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees
21.8: Neuroscience: Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees
The tasks of honeybee workers change with age. When young, they nurse the brood and when older, they forage for nectar and pollen. This…
Developmental Biology: Assessment of the Effects of Endocrine Disrupting Compounds on the Development of Vertebrate Neural Network Function
21.9: Developmental Biology: Assessment of the Effects of Endocrine Disrupting Compounds on the Development of Vertebrate Neural Network Function
Endocrine disrupting chemicals are known to adversely affect the nervous system. This protocol uses an in vitro invertebrate model to study the…
Biology: Collecting Hair Samples for Hair Cortisol Analysis in African Americans
21.10: Biology: Collecting Hair Samples for Hair Cortisol Analysis in African Americans
The stress hormone cortisol builds up in hair over time. Analyses of hair cortisol levels can provide useful information on long-term stress…