Chapter 18 - Endocrine System_Student (1)

Endocrine Glands

Glands that secrete hormones internally into the bloodstream without ducts.

Hormones

Chemical messengers secreted by endocrine glands that stimulate responses in distant targets.

Endocrine

effects are slower and longer lasting

Neuroendocrine Cells

Cells that exhibit characteristics of both the nervous system and endocrine glands.

Hypothalamus

A region of the brain that regulates the anterior pituitary gland through hormone release.

Pituitary Gland

An endocrine gland with two parts: adenohypophysis (anterior lobe) and neurohypophysis (posterior lobe).

Adenohypophysis

The anterior lobe of the pituitary gland that secretes various hormones.

Neurohypophysis

The posterior lobe of the pituitary gland that consists of nervous tissue and releases hormones.

Hypophysial Portal System

A system of blood vessels that connects the hypothalamus and the anterior pituitary gland.

Pineal Gland

A gland located at the roof of the third ventricle that secretes melatonin.

Melatonin

A hormone produced by the pineal gland that is involved in regulating circadian rhythms.

Thymus

A bi-lobed gland that produces hormones to stimulate the development of T cells.

Thyroid Gland

An organ that regulates metabolic rates through the secretion of thyroid hormones.

Parathyroid Glands

Four small glands on the posterior side of the thyroid that regulate calcium levels in the blood.

Adrenal Glands

Glands located atop the kidneys that have both endocrine and neuroendocrine functions.

Adrenal Cortex

The outer portion of the adrenal glands that secretes steroids.

Mineralocorticoids

Hormones secreted by the zona glomerulosa of the adrenal cortex that regulate mineral balance.

Glucocorticoids

Hormones secreted by the zona fasciculata of the adrenal cortex that regulate metabolism.

Androgens

Sex hormones secreted by the zona reticularis of the adrenal cortex.

Epinephrine

A hormone secreted by the adrenal medulla that increases metabolic rate and mobilizes energy.

Pancreas

An organ with both endocrine (insulin production) and exocrine functions.

Pancreatic Islets

Clusters of cells in the pancreas that have endocrine functions.

Alpha (α) Cells

Cells in the pancreas that secrete a hormone to raise blood sugar levels.

Beta (β) Cells

Cells in the pancreas that secrete a hormone to lower blood sugar levels.

Ovaries

Female gonads that produce hormones to regulate the menstrual cycle and pregnancy.

Testes

Male gonads that produce hormones regulating sex drive and sperm production.

Endemic Goiter

A swelling of the neck due to an enlarged thyroid caused by hyposecretion of thyroid hormone.

Diabetes Mellitus

A group of diseases that result in high blood sugar due to insulin issues.

Type I Diabetes

A form of diabetes characterized by autoimmune destruction of pancreatic beta cells.

Type II Diabetes

The most prevalent form of diabetes, often resulting from insulin receptor deficiency.

Hyposecretion

Insufficient hormone secretion from an endocrine gland.

Hypersecretion

Excessive hormone secretion from an endocrine gland.

Hormone Insensitivity

A defect in hormone receptors, causing lack of response to hormone signaling.

Renin

An enzyme secreted by the kidneys that regulates blood pressure and fluid balance by converting angiotensinogen to angiotensin I.

Angiotensinogen

A precursor protein produced by the liver, converted to angiotensin I by renin.

Angiotensin 1

A peptide hormone formed from the conversion of angiotensinogen by renin, which is further processed to produce angiotensin II.

Angiotensin 2

A potent vasoconstrictor that increases blood pressure and stimulates the release of aldosterone from the adrenal glands.

LH

crucial for regulating the menstrual cycle and ovulation in females and testosterone production in males.

FSH

A hormone produced by the pituitary gland that is essential for the development of ovarian follicles in females and spermatogenesis in males.

Gonadotropin RH (GnRH)

A hormone released by the hypothalamus that stimulates the release of LH and FSH from the anterior pituitary gland.

Growth hormone RH (GHRH)

A hormone produced by the hypothalamus that stimulates the release of growth hormone from the anterior pituitary gland.

GHIH (somatostatin)

A hormone produced by the hypothalamus that inhibits the release of growth hormone and other hormones from the anterior pituitary gland.

Thyrotropin RH (TRH)

Stimulates anterior pituitary to release thyroid-stimulating hormone (TSH) which regulates metabolism and thyroid function.

Prolactin RH (PRH)

A hormone released by the hypothalamus that promotes the secretion of prolactin from the anterior pituitary gland.

Prolactin IH (PIH)

A hormone produced by the hypothalamus that inhibits the secretion of prolactin from the anterior pituitary gland. AKA dopamine.

Corticotropin RH (CRH)

A hormone released by the hypothalamus that stimulates the anterior pituitary to secrete adrenocorticotropic hormone (ACTH), which in turn regulates cortisol production.

Oxytocin

A hormone produced by the hypothalamus and released by the posterior pituitary gland that stimulates uterine contractions during labor and milk ejection during breastfeeding.

Antidiuretic Hormone (ADH)

Targets the kidneys and blood vessels to increase water retention and reduce urine output, thereby helping to regulate body fluid balance. aka vasopressin.

TSH

A hormone produced by the anterior pituitary gland that stimulates the thyroid gland to produce and release thyroid hormones, which regulate metabolism.

GH

A hormone produced by the anterior pituitary that stimulates growth, cell reproduction, and regeneration in humans and other animals.

PRL

A hormone produced by the anterior pituitary gland that stimulates milk production in the mammary glands and plays a role in regulating the immune system.

TSH, ACTH, GH, FSH, LH, PRL

Anterior pituitary gland Hormones (6)

Oxytocin, ADH

Posterior Pituitary Gland Hormones (2)

Triiodothyronine (T3), Thyroxine (T4), Calcitonin

Thyroid Gland Hormones (3)

Calcitonin

A hormone produced by the thyroid gland that helps regulate calcium levels in the blood by lowering calcium levels when they are elevated.

triiodothyronine (T3) and Thyroxine (T4)

Targets most cells- stimulates cellular metabolism, growth, and differentiation.

Parathyroid

gland hormones that increase blood calcium levels by promoting calcium release from bones and enhancing kidney reabsorption of calcium.

Insulin

decreases blood glucose levels by facilitating cellular uptake of glucose and promoting glycogen storage in the liver.

glucagon

increases blood glucose levels by promoting the conversion of glycogen to glucose in the liver.

Adrenal Medulla

the inner part of the adrenal glands that produces hormones like adrenaline and norepinephrine, which help regulate the body's response to stress.

Adrenal Cortex

outer portion of the adrenal gland producing hormones: cortisol, aldosterone, and androgens and glucocorticoids.

Mineralocorticoids (aldosterone)

targets kidneys; increases retention of Na+ and excretion of K+ to regulate fluid balance and blood pressure.

Glucocorticoids

Targets most tissue; released in response to long-term stressors, increase blood glucose levels slowly and help regulate metabolism and immune responses. aka cortisol.

Androgens

Targets mosts tissues; stimulates development of sex characters and libido in both males and females.

Gastrin, Secretin, CCK

GI tract Hormones (3)

Gastrin

targets stomach; stimulates release of HCL

Secretin

targets pancreas and liver; stimulates secretion of bicarbonate and digestive enzymes.

Cholecystokin (CCK)

targets pancreas and liver; stimulates release of digestive enzymes and bile

Erythropoietin, Calcitriol

Kidney hormones (2)

Erythropoietin

Targets bone marrow; stimulates the production of rbc

Calcitriol

targets intestines; increases reabsorption of Ca2+

Atrial natriuretic peptide (ANP)

targets kidneys and adrenal cortex; reduces reabsorption of Na+ and lowers blood pressure.

Leptin

targets brain; supresses appetite and regulates energy balance.

Estrogen

stimulates uterine lining growth, regulates menstural cycle, facilitates development of secondary sex characteristics in females.

Progesterone

stimulates uterine lining growth, regulates menstural cycle and prepares the body for pregnancy.

inhibin

a hormone produced by the gonads that inhibits the release of follicle-stimulating hormone (FSH) from the anterior pituitary.

Human chorionic gonadotropin (hCG)

targets ovaries; stimulates the production of estrogen and progesterone

testosterone

a hormone produced by the testes that promotes the development of male secondary sexual characteristics and regulates spermatogenesis.