HORMONES MEMORIZATION

  • The anterior pituitary gland produces seven hormones, playing crucial roles in growth, metabolism, and the function of other endocrine glands:

    1. Follicle-Stimulating Hormone (FSH)

      • Origin: Anterior Pituitary Gland

      • Function: Stimulates ovarian follicle development in females and sperm production in males.

      • Stimulus: Gonadotropin-releasing hormone (GnRH) from the hypothalamus.

      • Target: Ovaries (follicle cells), Testes (Sertoli cells).

    2. Luteinizing Hormone (LH)

      • Origin: Anterior Pituitary Gland

      • Function: Triggers ovulation and corpus luteum formation in females; stimulates testosterone production in males.

      • Stimulus: Gonadotropin-releasing hormone (GnRH) from the hypothalamus.

      • Target: Ovaries (theca cells, corpus luteum), Testes (Leydig cells).

    3. Thyroid-Stimulating Hormone (TSH)

      • Origin: Anterior Pituitary Gland

      • Function: Stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4).

      • Stimulus: Thyrotropin-releasing hormone (TRH) from the hypothalamus.

      • Target: Thyroid Gland.

    4. Adrenocorticotropic Hormone (ACTH)

      • Origin: Anterior Pituitary Gland

      • Function: Stimulates the adrenal cortex to produce and release glucocorticoids (e.g., cortisol).

      • Stimulus: Corticotropin-releasing hormone (CRH) from the hypothalamus, stress.

      • Target: Adrenal Cortex.

    5. Human Growth Hormone (HGH)

      • Origin: Anterior Pituitary Gland

      • Function: Promotes growth of body tissues (bones, muscles) and influences metabolic processes (e.g., protein synthesis, fat breakdown).

      • Stimulus: Growth hormone-releasing hormone (GHRH) from the hypothalamus; sleep, exercise, low blood glucose.

      • Target: Liver (which produces IGF-1), bones, muscles, and other tissues.

    6. Prolactin (PRL)

      • Origin: Anterior Pituitary Gland

      • Function: Stimulates milk production in mammary glands after childbirth.

      • Stimulus: Prolactin-releasing hormone (PRH) from the hypothalamus; suckling during breastfeeding.

      • Target: Mammary Glands.

    7. Melanocyte-Stimulating Hormone (MSH)

      • Origin: Anterior Pituitary Gland

      • Function: Influences skin pigmentation (less impactful in humans than in other vertebrates).

      • Stimulus: Also derived from POMC, can be influenced by CRH.

      • Target: Melanocytes in the skin.

    Hormones Secreted by the Posterior Pituitary Gland

    The posterior pituitary gland stores and secretes two hormones that are produced by the hypothalamus:

    1. Oxytocin

      • Origin: Hypothalamus (neurons in paraventricular and supraoptic nuclei)

      • Function: Stimulates uterine contractions during childbirth and milk ejection (let-down reflex) during breastfeeding.

      • Stimulus: Pressure on the cervix (during labor), suckling, touch, sight, or sound of baby.

      • Target: Uterus (smooth muscle cells), Mammary Glands (myoepithelial cells).

    2. Antidiuretic Hormone (ADH) / Vasopressin

      • Origin: Hypothalamus (neurons in paraventricular and supraoptic nuclei)

      • Function: Promotes water reabsorption in the kidneys to conserve body water; also causes vasoconstriction to increase blood pressure.

      • Stimulus: Increased blood osmolarity (dehydration), decreased blood volume/pressure.

      • Target: Kidneys (renal tubules and collecting ducts), arterioles (smooth muscle cells).