lesson 2: endocrine system- negative feedback regulation

regulatory hormones of the hypothalamus: thyrotropin-releasing hormone (TRH)

promotes secretion of thyroid stimulating hormone (TSH)

regulatory hormones of the hypothalamus: corticotropin-releasing hormone (CRH)

promotes secretion of adrenocorticotropic hormone (ACTH)

regulatory hormones of the hypothalamus: gonadotropin-releasing hormone (GnRH)

promotes secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

regulatory hormones of the hypothalamus: growth hormone-releasing hormone (GHRH)

promotes secretion of growth hormone (GH)

regulatory hormones of the hypothalamus: somatostatin

inhibits secretion of growth hormone (GH)

regulatory hormones of the hypothalamus: prolactin-inhibiting hormone (PIH)

inhibits secretion of prolactin (PRL)

three negative feedback pathways: testosterone

-hypothalamus: GnRH (gonadotropin-releasing hormone)
-anterior pituitary gland: LH (luteinizing hormone)
-testis: testosterone

three negative feedback pathways: cortisol

-hypothalamus: CRH (corticotropin-releasing hormone)
-anterior pituitary gland: ACTH (adrenocorticotropic hormone)
-adrenal gland: cortisol (from the zona fasiculata)

three negative feedback pathways: thyroid hormone

-hypothalamus: TRH (thyrotropin-releasing hormone)
-anterior pituitary gland: TSH (thyroid-stimulating hormone)
-thyroid gland: thyroid hormone

thyroid hormone pathway: general function of thyroid hormones is to...

-increase basal metabolic rate (BMR)
-increase heat production

thyroid hormone pathway: target tissues of this pathway could include...

-anterior pituitary, thyroid, and tissues affecting body weight

hyperthyroidism is the ...

excessing production of thyroid hormone

hyperthyroidism symptoms include...

-increased BMR, a constant feeing of warmth, nervousness, and goiter (an enlarged thyroid gland)
-Grave's disease is the most common form

hypothyroidism (decreased levels of thyroid hormone) symptoms are...

-low BMR, decreased appetite, abnormal central nervous system development & intolerance to cold

cortisol pathway: cortisol promotes..

the breakdown of protein and fats and helps the body react to stress

cortisol pathway: target tissues of this pathway could include...

-anterior pituitary
-adrenals
-thymus
-tissues that affect body weight (adipose tissue)

hypercortisolism (excessive production) symptoms may include...

-hypertension (high blood pressure)
-osteoporosis
-atrophy of thymus due to thymocyte apoptosis
-weight loss
-general muscle wasting
-Cushing's syndrome is most common form

hypercortisolism (decreased levels of cortisol) symptoms are...

-altered metabolism
-mental confusion
-decreased ability to adapt to stress

testosterone pathway: testosterone is responsible for...

-male sex drive & secondary sex characteristics such as increased body hair and deep voice

testosterone pathway target tissues may include

-anterior pituitary
-testes
-sex organs like seminal vesicles and prostate

alterations in testosterone levels can promote...

premature sexual development, acne, male pattern baldness and infertility

in females, luteinizing hormone (LH) travels to the granulosa cells of...

the ovary to stimulate production and secretion of estrogens

estrogen participates in the regulation of...

-oocyte (egg) growth maturation
-works in first half of menstrual cycle to prepare of uterus for implantation
-causes the development of female secondary sexual characteristics and sustains the female reproductive tract

alterations to the normal level of estrogen can...

promote premature sexual development, infertility, and osteoporosis