What is the hypothalamic-pituitary target organ axis?
Among the target organs that constitute the hypothalamic-pituitary-target organ axis are the thyroid, the adrenal glands, and the gonads.
What is the hypothalamic-pituitary-ovarian axis?
The hypothalamic-pituitary-ovarian (HPO) axis is a tightly regulated system controlling female reproduction. HPO axis dysfunction leading to ovulation disorders can be classified into three categories defined by the World Health Organization (WHO).
What is the function of hypothalamic-pituitary gonadal axis?
The hypothalamic–pituitary–gonadal (HPG) axis is primarily responsible for regulating reproductive activity and the release of ovarian hormones in animals and humans (Couse et al., 2003; Meethal and Atwood, 2005).
What is the hypothalamic-pituitary cycle?
The Hypothalamus and the Pituitary It is released in a rhythmic fashion every 60 to 120 minutes. GnRH stimulates the pituitary gland to produce follicle stimulating hormone (FSH), the hormone responsible for starting follicle (egg) development and causing the level of estrogen, the primary female hormone, to rise.
What is the target organ of hypothalamus?
Pituitary gland
| Endocrine gland/ source of hormone | Hormone | Target organ or tissue |
|---|---|---|
| Hypothalamus | Numerous releasing factors | Pituitary gland |
| Anterior pituitary (adenohypophysis) | ACTH (adrenocorticotrophic hormone) | Adrenal cortex |
| FSH (follicle stimulating hormone) | Ovaries / testes (tubules) | |
| LH (luteinizing hormone) | Ovaries / testes (Leydig cells) |
How does the hypothalamic-pituitary-ovarian axis work?
The hypothalamic-pituitary-ovarian axis secretes hormones involved in reproduction. This gland secretes a variety of hormones, including a follicle-stimulating hormone (FSH) and a luteinizing hormone (LH). Ovary: the two ovaries located in a woman’s pelvis secrete estrogen and progesterone.
What stimulates the hypothalamus pituitary gonadal axis?
During puberty the HPG axis is activated by the secretions of estrogen from the ovaries or testosterone from the testes. This activation of estrogen and testosterone causes physiological and psychological changes.
Why is the hypothalamic pituitary axis important for hormone regulation?
Specifically, the hypothalamic-pituitary axis directly affects the functions of the thyroid gland, the adrenal gland, and the gonads, as well as influencing growth, milk production, and water balance (table 1) [1-4]. The anatomy and unique blood supply of the hypothalamic-pituitary axis are essential to its function.
What hormone stimulates the pituitary gland?
The major hormones produced by the pituitary gland are: ACTH: Adrenocorticotrophic hormone. Stimulates the production of cortisol, a “stress hormone” that maintains blood pressure and blood sugar levels. FSH: Follicle-stimulating hormone.
What are the six hormones of pituitary gland?
Hormones Secreted by Pituitary Glands and their Functions: Thyroid stimulating hormone (TSH) or Thyrotropin: This hormone which is secreted by the anterior lobe of the pituitary. Growth hormone (GH): Growth Hormone is also called as (hGH – Human Growth Hormone) or Somatotrophin. Growth hormone is released by the Anterior Pituitary. Prolactin (PRL): It is secreted by Anterior lobe of Pituitary. Prolactin hormone stimulates milk production in women following pregnancy. Men secrete Prolactin whose function is not known yet.
How do pituitary hormones affect the ovaries?
Follicle stimulating hormone of anterior pituitary stimulates growth of follicles in ovary. After development of follicles they start secreting estrogen. Lutinising hormone of pituitary stimulates one of the follicles to turn in graffian follicle. Graffian follicle in turn secretes progesterone another ovarian hormone.
What is GnRH hormone?
NP_032171. Gonadotropin-releasing hormone (GnRH) is a releasing hormone responsible for the release of follicle-stimulating hormone ( FSH ) and luteinizing hormone (LH) from the anterior pituitary. GnRH is a tropic peptide hormone synthesized and released from GnRH neurons within the hypothalamus.
Which anterior pituitary hormones regulate the ovarian cycle?
The anterior pituitary secretes two hormones that stimulate the growth and activity of the gonads, FSH and LH. These glycoprotein hormones, termed gonadotropins, work in conjunction to stimulate secretion of steroid hormones from the ovary. FSH is a glycoprotein with a molecular weight of approximately 29,000 daltons.