luteinizing hormone surge

(noun)

Acute rise of LH levels that triggers ovulation and development of the corpus luteum.

Related Terms

Examples of luteinizing hormone surge in the following topics:

  • Oogenesis

    • At the start of the menstrual cycle, some 12-20 primary follicles begin to develop under the influence of elevated levels of follicle-stimulating hormone (FSH) to form secondary follicles.
    • On day 14 of the cycle, a luteinizing hormone surge is triggered by the positive feedback of estrogen.
    • Differentiate among the stages of oogenesis and the actions of hormones during each stage

  • Ovaries

    • When oocyte maturation is completed, a luteinizing hormone (LH) surge secreted by the pituitary gland stimulates follicle rupture and oocyte release.

  • Uterine (Menstrual) Cycle

    • The discharge of blood slows and then stops in response to rising hormone levels and the lining of the uterus thickens, or proliferates.
    • Ovulation is triggered by a surge in luteinizing hormone.
    • The sudden change in hormones at the time of ovulation sometimes causes minor changes in the endometrium and light midcycle blood flow.
    • This hormone decrease causes the uterus to shed its lining and the egg in menstruation.

  • Hormonal Regulation of the Female Reproductive Cycle

    • Follicle-stimulating hormone induces the proliferation of granulosa cells in the developing follicles and the expression of luteinizing hormone (LH) receptors on these cells.
    • Estrogen levels are highest right before the LH surge begins.
    • The short-term drop in steroid hormones between the beginning of the LH surge and ovulation may cause mid-cycle spotting or bleeding.
    • The surge also initiates luteinization of theca and granulosa cells.
    • This is known as a secondary estrogen surge.

  • Hormonal Methods

    • Hormonal birth control contains steroid hormones that alter female fertility.
    • Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year.
    • Progesterone negative feedback decreases the frequency of gonadotropin-releasing hormone (GnRH) released by the hypothalamus, which decreases the release of follicle-stimulating hormone (FSH), and greatly decreases the release of luteinizing hormone (LH) by the anterior pituitary.
    • Progesterone negative feedback and the lack of estrogen positive feedback on LH release, prevent a mid-cycle LH surge.
    • Inhibition of follicular development and the absence of a LH surge prevent ovulation.

  • Hormonal Regulation of the Male Reproductive System

    • Hormonal control of spermatogenesis varies among species.
    • They are capable of producing the hormones estradiol and inhibin.
    • There it stimulates the synthesis and secretion of the gonadotropins, FSH and luteinizing hormone (LH).
    • Follicle-stimulating hormone (FSH)  is released by the anterior pituitary gland.
    • Luteinizing hormone (LH) is released by the anterior pituitary gland.

  • Female Hormones

    • As with the male, the hypothalamic hormone GnRH (gonadotropin-releasing hormone) causes the release of the hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone) from the anterior pituitary.
    • Follicle cells produce the hormone inhibin, which inhibits FSH production.
    • Estradiol and progesterone are steroid hormones that prepare the body for pregnancy.
    • Rising and falling hormone levels result in progression of the ovarian and menstrual cycles.
    • This mature egg follicle may rupture and release an egg in response to a surge of LH.

  • Onset, Duration, and Half-Life of Hormone Activity

    • A hormone's half-life and duration of activity are limited and vary from hormone to hormone.
    • A hormone's half-life and duration of activity are limited and vary from hormone to hormone.
    • For instance, the biological half-life of luteinizing hormone is 20 minutes, which is shorter than that of a follicle-stimulating hormone (three to four hours), and of human chorionic gonadotropin (24 hours).
    • Follicle-stimulating hormone 2.
    • Luteinizing hormone 4.

  • Ovarian Cycle

    • The main hormone controlling this stage is estradiol.
    • During the follicular phase, follicle-stimulating hormone (FSH) is secreted by the anterior pituitary gland.
    • FSH induces the proliferation of granulosa cells in the developing follicles and the expression of luteinizing hormone (LH) receptors on these granulosa cells.
    • Ovulation normally occurs 30 (± 2) hours after the beginning of the LH surge (when LH is first detectable in urine).
    • Because the hormone is unique to the embryo, most pregnancy tests look for the presence of hCG.

  • Hormone Receptors

    • A hormone receptor is a molecule that binds to a specific hormone.
    • Receptors for peptide hormones tend to be found on the plasma membrane of cells, whereas receptors for lipid-soluble hormones are usually found within the cytoplasm.
    • The hormone activity within a target cell is dependent on the effective concentration of hormone-receptor complexes that are formed.
    • Many hormones are composed of polypeptides—such as thyroid-stimulating hormones, follicle-stimulating hormones, luteinizing hormones, and insulin.
    • Lipophilic hormones—such as steroid or thyroid hormones—are able to pass through the cell and nuclear membrane; therefore receptors for these hormones do not need to be, although they sometimes are, located in the cell membrane.