What is the purpose of the HPG 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).
How does the HPG axis work?
The hypothalamic-pituitary-gonadal (HPG) axis coordinates a tightly regulated feedback loop that consists of gonadotropin-releasing hormone (GnRH) produced by the hypothalamus; follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary; and the sex steroids estrogen, progesterone, and …
When is the HPG axis active?
Objective: During puberty, the hypothalamus-pituitary-gonadal (HPG) axis is activated, leading to increases in luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex steroids (testosterone and estradiol) levels.
What are the effects of hypothalamic-pituitary-ovarian-axis disorders?
Hypothalamic Pituitary Failure Group I ovulation disorders, hypothalamic-pituitary failure (HPF) manifests as hypogonadotropic hypogonadism. Females with HPF typically present with delayed or impaired pubertal development, primary or secondary amenorrhea, and infertility.
What is the medical term for failure of the ovaries?
A disruption of this process results in reproductive failure (anovulation) or endocrine failure (low serum levels of ovarian steroid hormones and inhibins). Ovarian failure due to inappropriate regulatory signals (hypothalamic or pituitary pathology) is known as secondary ovarian failure.
Why is hypopituitarism also known as complete pituitary failure?
Hypopituitarism does occasionally start suddenly with rapid onset of symptoms. This condition represents the loss of all hormones released by the anterior pituitary gland. Panhypopituitarism is also known as complete pituitary failure. There are three major mechanisms which lead to the development of hypopituitarism.
What are the symptoms of hypothalamic pituitary dysfunction?
Frequently, patients have had years of symptoms that were nonspecific until a major illness or stress occurred. Overall symptoms may include fatigue, sensitivity to cold, weakness, decreased appetite, weight loss and abdominal pain. Low blood pressure, headache and visual disturbances are other associated symptoms.