menstruation normally but suffer from amenorrhea(absence of periods)
in later years
General factors
- thyroid disorders, adrenal disease
- presence of autoimmune antibodies
- heavy alcohol use, drugs, toxins (pesticides and lead), smoking,
medicines, radiation treatment, chemotherapy for cancer, etc.
-smokingreduces the age of menopause
insufficiency, or in systemic diseases such as diabetes, scleroderma, and amyloidosis. Idiopathic gastroparesis occurring in the absence of systemic illness may follow a viral prodrome, suggesting an infectious etiology. Intestinal pseudoobstruction is characterized by disrupted intestinal and colonic motor activity and leads to retention of food residue and secretions, bacterial overgrowth, nutr
Dopamine is biosynthesized mainly by nervous tissue and the medulla of the adrenal glands.
As a member of the catecholamine family, dopamine is a precursor to epinephrine (adrenaline) and then norepinephrine (noradrenaline) in the biosynthetic pathways for these neurotransmitters.
1. PreSynaptic neurons secrete Dopamine -> Dopamine + receptors of PostSynaptic cells (Dopamin + receptor D1,