Endocrine System
Communication system that sends long-lasting and more generalized hormones to target cells via the bloodstream in response to stimuli
Nervous System
Communication system that sends specific and lightning-fast action potentials to target cells in response to stimuli
Exocrine Glands
Glands with ducts that secrete products outside of the cell, and tends to have extracellular effects
Endocrine Glands
Glands with no ducts that are secreted directly into the bloodstream and have intracellular effects
Adenohypophysis
Anterior pituitary gland. Is a true endocrine gland, linked to hypothalamus via the hypophysial portal system, and secretes FSH, LH, TSH, ACTH, PRL, and GH.
Follicle-stimulating hormone (FSH)
Hormone secreted by the Adenohypophysis that stimulates the secretion of ovarian sex hormones, sperm production, and the development of the ovarian follicles
Luteinizing hormone (LH)
Hormone secreted by the Adenohypophysis that stimulates ovulation and progesterone production in females and the production of testosterone in males
Thyroid-stimulating hormone (TSH)
Hormone secreted by the Adenohypophysis that simulates the secretion of thyroid hormones
Adrenocorticotropic hormone (ACTH)
Hormone secreted by the Adenohypophysis that stimulates the adrenal cortex to secrete glucocorticoids
Prolactin (PRL)
Hormone secreted by the Adenohypophysis that stimulates milk production in the mammary glands
Growth Hormone (GH)
Hormone secreted by the Adenohypophysis that stimulates mitosis and cellular differentiation
Neurohypophysis
Posterior pituitary gland. Not a true gland, as it contains nerve tissue. Nerves in the hypothalamus pass down to the pituitary gland via the hypothalamo–hypophysial tract, and the nerves secreted from the gland are actually made in the hypothalamus
Antidiuretic hormone (ADH)
Vasopressin; hormone created by the hypothalamus and secreted by the neurohypophysis that retains water, decreases urination, and constricts the blood vessels (vasoconstriction)
Oxytocin
Hormone created by the hypothalamus and secreted by the neurohypophysis that is responsible for sexual pleasure, emotional bonding, the movement of milk in the mammary glands, and labor
Hypothalamus
Neuroendocrine structure that forms the floor and walls of the third ventricle of the brain; creates eight hormones, two of which are released by the posterior pituitary gland
Gonadotropin-releasing hormone (GnRH)
Hormone created and released by the hypothalamus that stimulates the release of LH and FSH
Thyrotropin-releasing hormone (TRH)
Hormone created and released by the hypothalamus that stimulates the release of TSH
Corticotropin-releasing hormone (CRH)
Hormone created and released by the hypothalamus that stimulates the release of ACTH
Prolactin-inhibiting hormone (PIH)
Hormone created and released by the hypothalamus that inhibits the secretion of the hormone prolactin
Growth hormone-releasing hormone (GHRH)
Hormone created and released by the hypothalamus that stimulates the release of growth hormone
Somatostatin
Hormone created and released by the hypothalamus that inhibits the release of growth hormone and thyroid-stimulating hormone
Pineal gland
Shrunken gland located in the brain that is responsible for secreting melatonin
Melatonin
Hormone released by the pineal gland that has a role in sleep and the circadian rhythm
Thymus
Gland superior to the heart that also plays a role in the lymphatic and immune systems; serves as the site of maturation for T cells and secretes thymopoietin, thymosin, and thymulin to help develop the lymphatic system
Thymopoietin, thymosin, and thymulin
Hormones secreted by the thymus that develops the lymphatic system
Thyroid
Butterfly-shaped gland just below the larynx that secretes thyroxine and triiodothyronine in response to TSH release
Thyroxine (T4) and triiodothyronine (T3)
A pair of hormones secreted by the thyroid gland that increases the metabolic rate of the body, which subsequently increases O2 demand, appetite, alertness, reflex speed, and growth hormone secretion
Parafollicular Cells
Cells located in the thyroid that secretes calcitonin
Calcitonin
Hormone secreted by the parafollicular cells in the thyroid that stimulates bone formation and osteoblasts in children
Parathyroid glands
Glands located on the thyroid that secretes parathyroid hormone
Parathyroid hormone (PTH)
Hormone secreted by the parathyroid glands that promotes the synthesis of calcitriol and the subsequent retention of calcium ions
Adrenal Glands
Two glands that sit on the top of the kidneys that releases hormones that regulate metabolism and prepare the body for “fight or flight”
Adrenal Medulla
The inner 10-20% of the adrenal gland; has neuroendocrine properties and is able to release both dopamine and catecholamines into the bloodstream
Catecholamines
Epinephrine and Norepinephrine; hormones that increase alertness and prepare the body for physical activity
Adrenal Cortex
Outer portion of the adrenal gland that secretes mineralocorticoids, sex steroids, and glucocorticoids
Mineralocorticoids
Steroid hormones like aldosterone secreted by the adrenal cortex that regulates electrolyte balance
Aldosterone
A mineralocorticoid that stimulates sodium retention and potassium excretion. It is part of a system with renin and angiotensin (RAA).
Glucocorticoids
Hormones secreted by the adrenal cortex that regulate the metabolism of fuels like glucose
Cortisol and Corticosterone
Pair of hormones secreted by the adrenal cortex that helps break down fats and proteins, the release of fatty acids and glucose into the blood, and gluconeogenesis
Androgens
Sex steroid secreted by the adrenal cortex that sets libito and plays a large role in male development
Estradiol
Sex steroid secreted in small amounts by the adrenal cortex that sustains adult bone mass after menopause
Pancreas
Gland that sits above the beginning of the small intestine that contains alpha and beta cells responsible for managing the levels of glucose in the blood
Glucagon
Hormone secreted by alpha cells in the pancreas; raises blood glucose, stimulates gluconeogenesis and glycogenolysis, releases free fatty acids from fat tissue, and promotes amino acid absorption for gluconeogenesis
Insulin
Hormone secreted by beta cells in the pancreas; lowers blood glucose, gets cells to absorb and store glucose, and promotes synthesis of glycogen, fat, and protein. The brain, liver, kidneys, and red blood cells do not need this hormone to function
Gonads
The ovaries in females and testes in males. Are both exocrine and endocrine in nature
Estradiol, progesterone, and inhibin
Hormones secreted by the ovaries
Testosterone, weaker androgens, estrogen, and inhibin
Testicular hormones
Skin
Able to convert a cholesterol-like steroid into cholecalciferol using the UV light from the sun
Liver
Digestive organ involved in the production of at least five hormones; calcidiol, angiotensinogen, erythropoietin, IGF-I, and hepcidin
Kidneys
Produces three hormones'; calcitriol (active form of vitamin D), renin, and erythropoietin
Heart
Able to secrete two natriuretic peptides to decrease blood pressure
Stomach/small intestine
Digestive organs that can secrete at least 10 hormones that can coordinate digestive motility and glandular secretion; cholecystokinin, gastrin, ghrelin, and peptide YY
Adipose tissue
Tissue that is able to secrete leptin, which slows appetite
Osseous tissue
Tissue that secretes osteocalcin, which increases number of beta cells, insulin output, and insulin sensitivity
Placenta
Secretes estrogen and progesterone to regulate pregnancy and the development of the fetus and mammary glands
Peptides and catecholamines
Water-soluble hormones that cannot pass through the target cells; must bind to surface receptors to activate intracellular processes through second messangers
Steroids and thyroid hormones
Lipid-soluble hormones that can pass through the target cell’s cell membrane; binds to internal receptors and influence the expression of genes of the target cell