Endocrine System Overview Quiz

Hormones and Their Functions

• Hypothalamus Hormones:

  • GHRF: Stimulates secretion of growth hormone (GH).
  • Somatostatin: Inhibits secretion of GH.
  • Thyrotropin-releasing factor (TRF): Stimulates secretion of thyroid-stimulating hormone (TSH).
  • Corticotropin-releasing factor (CRF): Stimulates secretion of TSH.
  • Prolactin-inhibiting factor (PIF): Inhibits prolactin secretion.
  • Gonadotropin-releasing hormone (GnRH): Stimulates secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

• Pituitary Gland Hormones:

  • TSH: Stimulates thyroid gland and regulates cell proliferation.
  • ACTH: Stimulates adrenal cortex.
  • FSH: Promotes follicle growth.
  • LH: Induces ovulation and testosterone release (interstitial cell-stimulating hormone, ICSH).
  • GH: Supports cell growth, division, metabolism, and protein synthesis; disorders include dwarfism (low GH), gigantism (high GH in childhood), and acromegaly (high GH in adults).
  • Prolactin (LTH): Stimulates lactation and breast development.
  • MSH: Promotes melanin production.
  • ADH (Vasopressin): Aids water reabsorption, increases blood volume, and blood pressure; deficiency leads to diabetes insipidus.
  • Oxytocin: Triggers labor and lactation; excessive levels can lead to complications such as uterine wall rupture.

Glandular Hormones and Disorders

• Pineal Gland:

  • Melatonin: Regulates biological clock, sleep cycles, and gonadal development.

• Thyroid Gland:

  • T3 and T4: Crucial for maintaining basal metabolic rate (BMR), glucose metabolism, and overall physical growth; disorders include hyperthyroidism (high levels), hypothyroidism (low levels), and developmental disorders like cretinism (children) and myxedema (adults).
  • Calcitonin: Lowers blood calcium levels; dysfunction can lead to hypercalcemia or hypocalcemia.

• Parathyroid Gland:

  • Parathyroid hormone (PTH): Increases blood calcium levels; disorders include hypercalcemia (excess PTH) and hypocalcemia (insufficient PTH).

• Thymus Gland:

  • Thymosin: Facilitates maturation of T-lymphocytes (white blood cells).

• Pancreas:

  • Insulin: Lowers blood sugar levels; insufficient insulin results in diabetes mellitus.
  • Glucagon: Increases blood sugar levels; low glucagon can lead to hypoglycemia.

• Adrenal Gland:

  • Epinephrine and norepinephrine: Enhance heart rate, blood pressure, and glucose levels; can cause hypertension and aggressive behavior when elevated.
  • Aldosterone: Promotes reabsorption of sodium and chloride.
  • Androgens: Influence secondary sexual characteristics; excess can cause masculinization in females.
  • Cortisol: Reduces inflammation and pain, aids glycogen metabolism; disorders include Addison’s disease (low cortisol) and Cushing syndrome (high cortisol).

• Ovaries:

  • Estrogen: Promotes secondary sexual characteristics; low levels can lead to sterility and high levels are associated with fibroids and polycystic ovaries.
  • Progesterone: Prevents ovulation and maintains pregnancy; low levels can trigger early menstruation and increase miscarriage risk.

• Testes:

  • Testosterone: Essential for male reproductive organ development, secondary sexual traits, libido, and normal sperm production; deficiencies lead to feminine characteristics and male sterility.

Kidneys

• Renin: Monitors blood pressure.
• Calcitriol: Increases intestinal absorption of calcium.
• Erythropoietin (EPO): Stimulates red blood cell production in response to low oxygen levels or bleeding.