Detailed Notes on Chapter 17: The Endocrine System

Homeostasis

The body's goal of maintaining a stable internal environment.

Neurotransmitter

Chemical signals that act locally and rapidly across the synaptic cleft.

Hormone

Chemical signals in the endocrine system that are transported via the bloodstream to target cells.

Endocrine system

A system primarily using chemical signaling to regulate physiological processes over a longer distance and time than the nervous system.

Nervous system

A system that uses both electrical and chemical signals for rapid communication.

Pituitary gland

The gland often referred to as the 'mothership' of the endocrine system, controlling functions of other endocrine glands.

Hypothalamus

A brain structure that regulates hormone secretion from the pituitary gland and coordinates the endocrine system.

Negative feedback loop

A regulatory mechanism wherein increased output leads to a decrease in the process, maintaining homeostasis.

Releasing hormone

Hormones produced by the hypothalamus to stimulate the secretion of hormones from the anterior pituitary.

Antidiuretic hormone (ADH)

Hormone that increases water reabsorption in the kidneys, reducing urine output in response to high blood osmolarity.

Oxytocin

Hormone that stimulates uterine contractions during labor and milk ejection during breastfeeding.

Glucagon

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

Insulin

Hormone secreted by the beta cells of the pancreas that lowers blood glucose levels.

Thyroid gland

An endocrine gland that produces hormones influencing metabolic rate and calcium homeostasis.

Calcitonin

Hormone produced by parafollicular cells of the thyroid that lowers blood calcium levels.

Parathyroid hormone (PTH)

Hormone that raises blood calcium levels by stimulating osteoclast activity and reabsorption of calcium in the kidneys.

Adrenal glands

Glands atop the kidneys that produce hormones involved in stress response and metabolism.

Epinephrine

A hormone also known as adrenaline that prepares the body for fight or flight in response to stress.

Cortisol

A glucocorticoid hormone that regulates glucose metabolism and helps manage stress.

Melatonin

Hormone produced by the pineal gland that regulates sleep-wake cycles.

Androgens

Hormones associated with male traits and reproductive activity.

Estrogens

Hormones that regulate female reproductive functions and characteristics.

Progesterone

Hormone involved in the regulation of the menstrual cycle and maintenance of pregnancy.

Gonadotropin releasing hormone (GnRH)

A hormone from the hypothalamus that stimulates the secretion of gonadotropins from the anterior pituitary.

Prolactin

Hormone that promotes milk production in females.

Thyroid Stimulating Hormone (TSH)

Hormone from the anterior pituitary that stimulates the thyroid gland to produce thyroid hormones.