Endocrine System unit 5

Antidiuretic hormone (ADH)

Secreted by: posterior pituitary (made in hypothalamus)

Stimulus: increased blood osmolarity

Target tissue: collecting and papillary ducts of kidneys

Oxytocin (OT)

Secreted by: posterior pituitary (made in hypothalamus)

Stimulus: infant suckling, fetal oxytocin secretion

Target tissue: milk ducts and uterus

Thyroid-stimulating hormone

Secreted by: anterior pituitary

Stimulus: thyrotropin-releasing hormone

Target tissue: thyroid gland

Adrenocorticotropic hormone

Secreted by: anterior pituitary

Stimulus: corticotropin-releasing hormone

Target tissue: adrenal cortex

Growth Hormone (GH)

Secreted by: anterior pituitary

Stimulus: growth hormone-releasing hormone

Target tissue: nearly all body cells

Prolactin

Secreted by: anterior pituitary

Stimulus: prolactin-releasing hormone

Target tissue: mammary gland

Melatonin

Secreted by: pineal gland

Stimulus: decreasing ambient light levels

Target tissue: reticular formation in the brainstem

Thyroxine (T3) and Triiodothyronine (T4)

Secreted by: thyroid gland

Stimulus: thyroid-stimulating hormone

Target tissue: most body cells

Calcitonin

Secreted by: thyroid gland

Stimulus: increasing blood calcium ion concentrations

Target tissue: bone

Thymosin and thymopoietin

Secreted by: thymus

Stimulus: presence of immature T-lymphocytes

Target tissue: T lymphocytes in the thymus

Parathyroid hormone

Secreted by: parathyroid glands

Stimulus: decreasing blood calcium ion concentrations

Target tissue: bone, kidneys, small intestine

Cortisol

Secreted by: adrenal cortex

Stimulus: ACTH

Target tissue: most body cells (liver, adipocytes, muscle cells)

Aldosterone

Secreted by: adrenal cortex

Stimulus: Angiotensin II, ACTH, high potassium/hydrogen ions

Target tissue: cells of distal tubules of kidneys

Epinephrine & Norepinephrine

Secreted by: adrenal medulla

Stimulus: sympathetic nervous system neurons

Target tissue: most body cells

Insulin

Secreted by: pancreas

Stimulus: increasing blood glucose concentrations

Target tissue: all body cells

Glucagon

Secreted by: pancreas

Stimulus: decreasing blood glucose, presence of protein

Target tissue: liver, adipocytes, muscle

Oxytocin (OT)

Produced by hypothalamus and stored in posterior pituitary; stimulates uterine contractions and milk ejection.

Antidiuretic hormone (ADH)

Stimulates water reabsorption in the kidneys, decreasing urine production and increasing permeability to water.

Human Growth Hormone (HGH)

Produced by anterior pituitary to stimulate the rate of cell division.

Prolactin (PRL)

Secreted by anterior pituitary to stimulate milk production (lactation) in mammary glands.

Follicle stimulating hormone (FSH)

Stimulates ovaries to produce estrogen and mature follicles, or stimulates sperm production in testes.

Luteinizing hormone (LH)

Triggers ovulation, estrogen/progesterone production in females, and testosterone secretion in males.

Thyroid stimulating hormone (TSH)

Stimulates thyroid to release T3 and T4 to increase metabolism, blood pressure, and regulate growth.

Adrenocorticotrophic hormone (ACTH)

Stimulates adrenal cortex to release glucocorticoids and androgens.

Calcitonin

Secreted by thyroid gland to lower blood calcium levels by triggering osteoblast activity.

Parathyroid hormone (PTH)

Secreted by parathyroid gland to increase blood calcium levels by triggering osteoclast activity and kidney/intestine reabsorption.

Insulin

Secreted by beta islet cells of pancreas to reduce blood sugar levels via cellular uptake.

Glucagon

Secreted by pancreas to increase blood sugar levels by releasing stored glucose/glycogen from the liver.

Melatonin

Secreted by pineal gland to help regulate biological clocks and sleep.

Epinephrine

Secreted by adrenal medulla to promote short-term stress response (increased heart rate, vasodilation, dilated airways).

Norepinephrine

Secreted by adrenal medulla to promote short-term stress response with vasoconstriction.

T3 and T4

Secreted by thyroid gland to increase body metabolism, blood pressure, and regulate tissue growth.

Cortisol

Secreted by adrenal cortex to regulate long-term stress response (increases blood glucose, decreases inflammation).

Aldosterone

Secreted by adrenal cortex to conserve sodium ions and excrete potassium ions for electrolyte balance.

Thymosin

Secreted by thymus to promote maturation of T cells for immune response.

Testosterone

Stimulates development of male secondary sexual characteristics and sperm production.

Progesterone

Produced by ovaries to help regulate the menstrual cycle.

Estrogen

Promotes development of oocytes and female secondary sex characteristics.

Melanotropins (MSH)

Protect skin from UV rays, develop pigmentation, and control appetite.

Leptin

Released from adipose tissue to signal appetite and food intake.

Ghrelin

Released by the stomach to stimulate appetite and food intake.

Atrial natriuretic peptide (ANP)

Released by the heart to lower blood pressure and control electrolyte homeostasis.

Gastrin

Secreted by the stomach to stimulate gastric juice secretion (HCl).

Secretin

Secreted by the small intestine to stimulate the pancreas to release bicarbonate-rich pancreatic juices.

Corticotropin-releasing hormone (CRH)

Released from hypothalamus to stimulate anterior pituitary to release ACTH.

Brain natriuretic peptide (BNP)

Released in response to cardiac myocyte wall stress to promote vasodilation.

Cholecystokinin

Causes release of bile to digest fat/proteins and acts as a hunger suppressant.

Thyrotropin-releasing hormone (TRH)

Produced by hypothalamus neurons to stimulate release of TSH and prolactin from anterior pituitary.

Undersecretion of Human Growth Hormone

Results in dwarfism.

Oversecretion of Human Growth Hormone

Results in gigantism.

Simple Goitre Cause

Deficiency of iodine in the diet causes goitre.

Hyposecretion of Insulin

Leads to diabetes mellitus.

Alpha Cells of Pancreas

Secrete glucagon to increase blood sugar levels.

Beta Cells of Pancreas

Secrete insulin to reduce blood sugar levels.