Endocrine System and Hormonal Regulation

This flashcard set covers the hormones, endocrine glands, target organs, and physiological effects discussed in the lecture notes, including the mechanisms of action for the pituitary, thyroid, adrenal, and pineal glands.

Hormones

Chemical signals secreted by endocrine glands that communicate regulatory messages within the body, coordinating responses to stimuli like stress, dehydration, and low blood glucose.

Oxytocin

A hormone from the posterior pituitary gland that targets the mammary gland and uterus to cause uterine contractions during labor and milk ejection.

Antidiuretic hormone (ADH)

Also known as Vasopressin, this posterior pituitary hormone acts on the kidneys to promote water retention and regulate blood osmolality via negative feedback.

Vasoconstriction

An effect associated with Vasopressin (ADH) that leads to an increase in blood pressure.

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

Hormones produced by the anterior pituitary gland that stimulate the activities of the gonads (testes and ovaries).

Thyroid-stimulating hormone (TSH)

An anterior pituitary hormone that targets the thyroid gland to promote its development and the production of thyroid hormones.

Adrenocorticotropic hormone (ACTH)

A hormone from the anterior pituitary gland that targets the adrenal cortex to stimulate the production and secretion of steroid hormones.

Negative Feedback (ACTH Mechanism)

The process where Cortisol inhibits the Hypothalamus (CRH) and Pituitary Gland (ACTH) through short loop and long loop inhibition.

Prolactin

An anterior pituitary hormone that stimulates mammary gland growth and milk production; it also regulates fat metabolism in birds and salt/water balance in freshwater fish.

Melanocyte-stimulating hormone (MSH)

An anterior pituitary hormone that targets pigment-containing cells in the skin of some fishes, amphibians, and reptiles, and inhibits hunger in mammals.

$\beta$-endorphin

A hormone from the anterior pituitary gland that acts on the brain to dull the perception of pain.

Growth hormone (GH)

Produced by the anterior pituitary, it targets the liver and bone to release insulin-like growth factors (IGFs) for growth and raises blood glucose.

Triiodothyronine ($T_3$) and thyroxin ($T_4$)

Hormones that regulate brain development, bioenergetics, homeostasis, and the metamorphosis of a tadpole into a frog.

Parathyroid hormone (PTH)

Produced by the parathyroid glands, it acts on bone cells and kidneys to regulate calcium homeostasis and activate vitamin D for gut absorption.

Calcitonin

A hormone from the thyroid glands that targets bone cells to maintain calcium homeostasis.

Insulin and Glucagon

Pancreatic hormones that regulate blood glucose levels in all body cells except the brain.

Epinephrine and Norepinephrine

Also known as adrenaline and noradrenaline, these adrenal medulla hormones provide a rapid bioenergetic boost to skeletal muscles and the respiratory system.

Glucocorticoids (e.g., cortisol)

Produced by the adrenal cortex, these influence bioenergetics/glucose metabolism and suppress the body's immune system.

Mineralocorticoids (e.g., aldosterone)

Hormones produced by the adrenal cortex that maintain salt and water balance at the kidney.

Progesterone

A hormone produced in the testes, ovaries, and adrenal cortex that promotes uterine lining growth.

Estrogen

Hormone responsible for the development and maintenance of the female reproductive system and secondary sex characteristics.

Androgen

Hormones responsible for the development of male secondary sex characteristics.

Melatonin

A hormone from the pineal gland that targets neurons in the suprachiasmatic nucleus to regulate biorhythms such as the biological clock.