BSC 2085 Exam 5 Review: The Endocrine System

Complete set of vocabulary flashcards covering the endocrine system components, hormones, target tissues, and functions as described in the lecture review lecture.

Exocrine glands

Glands that secrete non-hormonal products, such as sweat or mucus, via ducts.

Endocrine glands

Glands that secrete hormones into interstitial fluid, which then diffuse into tissue capillaries.

Paracrine

A hormone classification where chemicals are diffused locally to affect neighboring target cells.

Autocrine

A hormone classification where chemicals act on the same cell that produced them.

Water-soluble hormones

Hormones that bind to cell surface receptors on the plasma membrane because they cannot diffuse through the lipid bilayer; includes amine, peptide, and eicosanoid hormones.

Lipid-soluble hormones

Hormones that diffuse through the lipid bilayer and bind to intracellular receptors in the cytosol or nucleus; includes steroid hormones, thyroid hormones ($T_3$, $T_4$), and nitric oxide.

Hypothalamic-pituitary axis (HPA)

The system formed by the hypothalamus and pituitary gland to provide diffuse endocrine regulation.

Thyroid-stimulating hormone (TSH)

An anterior pituitary hormone that stimulates the thyroid gland to secrete $T_3$ and $T_4$.

Adrenocorticotropin hormone (ACTH)

An anterior pituitary hormone that stimulates the adrenal cortex to secrete glucocorticoids, specifically cortisol.

Growth hormone (hGH)

A hormone that targets the liver, skeletal muscle, and bone to stimulate the secretion of growth factors like IGFs.

Follicle stimulating hormone (FSH)

A gonadotropin that stimulates ovarian follicle development and estrogen production in ovaries, or sperm production in testes.

Luteinizing hormone (LH)

A hormone that triggers ovulation and the formation of the corpus luteum in ovaries, or stimulates testosterone secretion in testes.

Oxytocin (OT)

A posterior pituitary hormone responsible for milk letdown reflexes and uterine contractions during birth.

Antidiuretic hormone (ADH)

Also known as vasopressin, it increases water reabsorption in the kidneys to increase blood volume and decrease urine volume.

Thyroxine ($T_4$) and Triiodothyronine ($T_3$)

Hormones secreted by thyroid follicular cells that increase oxygen consumption, metabolism, heart rate, and blood pressure.

Calcitonin (CT)

A hormone secreted by thyroid parafollicular cells that lowers $Ca^{2+}$ levels in the blood.

Parathyroid Hormone (PTH)

A hormone secreted by parathyroid chief cells that increases $Ca^{2+}$ levels in the blood.

Zona glomerulosa

The outer zone of the adrenal cortex that secretes mineralocorticoids, such as aldosterone.

Zona fasciculata

The middle zone of the adrenal cortex that secretes glucocorticoids, such as cortisol.

Zona reticularis

The inner zone of the adrenal cortex that secretes androgens, such as DHEA.

Chromaffin cells

Specific cells in the adrenal medulla that secrete catecholamines (epinephrine and norepinephrine).

Erythropoietin (EPO)

A kidney hormone that targets red bone marrow to increase red blood cell production.

Calcitriol

A hormone secreted by the kidneys that increases the absorption of calcium and phosphorus from digested food in the intestines.

Renin

A hormone synthesized by juxtaglomerular cells that targets angiotensinogen and triggers the production of aldosterone.

Islets of Langerhans

Cell clusters in the pancreas containing alpha, beta, delta, epsilon, and F cells that perform endocrine functions.

Glucagon

A hormone secreted by pancreatic alpha cells that increases blood glucose levels through glycogenolysis and gluconeogenesis.

Insulin

A hormone secreted by pancreatic beta cells that decreases blood glucose by promoting glycogenesis and glucose uptake by tissues.

Somatostatin (GHIH)

Secreted by delta cells of the pancreas; inhibits insulin and glucagon secretion and slows nutrient absorption in the GI tract.

Ghrelin

A hormone produced by epsilon cells of the pancreas and the GI tract that targets the brain to stimulate hunger.

Leydig cells

Cells located in the testes responsible for the secretion of testosterone.

Sertoli cells

Supportive cells in the testes that aid in sperm maturation and secrete inhibin and activin.

Pineal gland

An endocrine gland that secretes melatonin to regulate circadian rhythms.

Thymus

A gland responsible for the maturation of T lymphocytes for the adaptive immune system by secreting hormones like thymosin.

Atrial natriuretic peptide (ANP)

A hormone secreted by the heart that decreases aldosterone release and inhibits renin secretion.

Cholecalciferol

A precursor to vitamin D secreted by the skin in the presence of UV light.

Leptin

A hormone secreted by adipose (fat) tissue that suppresses appetite and increases metabolism.