Endocrine Physiology 2 Flashcards
Hypothalamic releasing and inhibiting factors (hypophysiotrophic hormones) affect
the release of the ant pituitary hormones
The ___ partially controls the release of the ant pituitary hormones through ___
Hypothalmus Through the releasing and inhibiting factors it puts into the portal system to the ant pituitary These factors (except dopamine) are peptides
Hypothalamic factors include
CRH for control of ACTH TRH for control of TSH Hypothalamic gonadotropin releasing hormone for control of FSH and LH GHRH Somatostatin Dopamine (prolactin inhibiting factor)
Anterior pituitary gland is controlled by
releasing and inhibitory hormones secreted into the hypophyseal portal circulation
These hormones reach the ant pit directly through this portal circulation without going into general circulation
Specific secretory cell types of the ant pituitary secrete 6 major tropic hormones - what are they
TSH* ACTH* FSH* LH* Prolactin - not really tropic GH - has tropic and non tropic effects
Neurons in the hypothalamus synthesize what
oxytocin and antidiuretic hormone
Hormones are transported to the post pit for release
Anterior pit is an ___ ___
endocrine gland
Ant pit is controlled by
Releasing and inhibitory hormones that pass from the hypothalamus to the ant pituitary by a vascular hypothalmic hypophyseal portal system
Tropic hormones
Endocrine gland is itself a target organ for another hormone
Adrenocorticotrophic hormone is made in the
corticotroph cells of the anterior pituitary
Adrenocorticotrophic hormone is AKA
ACTH or Corticotropin
Famous function of ACTH (Adrenocorticotrophic hormone or Corticotropin)
Famous thing is stress (can be physical, emotion, chemical, or others)
Function of ACTH (Adrenocorticotrophic hormone or Corticotropin) - Stimulates the synthesis and secretion of what
Adrenocortical hormones including
- Cortisol
- Androgens
- Aldosterone
All secreted by the adrenal cortex
Main effect of ACTH (Adrenocorticotrophic hormone or Corticotropin)
Stimulation of cortisol synthesis and secretion
At physiological levels, little or no effect on aldosterone secretion rate form the adrenal glands
ACTH (Adrenocorticotrophic hormone or Corticotropin) - ACTH - Primary adrenal insufficiency
melanotropin receptors on melanocytes and accelerate melanin synthesis
Primary adrenal insufficiency can cause hyperpigmentation because ant pit makes excessive ACTH since feedback inhibition by cortisol does not occur
ACTH (Adrenocorticotrophic hormone or Corticotropin) - Androgens
DO NOT feedback inhibit ACTH secretion
ACTH (Adrenocorticotrophic hormone or Corticotropin) - What causes the release of ACTH
Corticotropin releasing hormone (CRH) from the hypothalamus (RH will always be from hypothalamus)
ACTH (Adrenocorticotrophic hormone or Corticotropin) - What causes the release of ACTH? What causes release of that?
Release of CRH is stimulated by psychological or physical stress
CRH from hypo causes ACTH secretion from ant pit
Prolactin - tropic?
Not technically - because it makes the breast develop tissue that is necessary to make milk - it does not act on another gland like most tropic hormones do
Prolactin plays important role in
Normal development of mammary tissue and in milk production
Main release of prolactin is through
Inhibitory mechanism by dopamine
Release of prolactin is under negative control by the hypothalamic dopamine
What stimulates the release of prolactin
Sucking - there is a dec in the release of dopamine so it has a positive effect on the release of prolactin
Prolactin - inhibition of its release
Prolactin inhibits its own release by stimulating dopamine release from the hypothalamus
Prolactin abbreviation is
PRL
Prolactin is produced by what
Lactotropes of the ant pituitary
Sheehan syndrome AKA
Postpartum hypopituitarism
Sheehan syndrome - describe
Pituitary approx doubles in size with normal pregnancy - this inc the needed blood supply
If pt becomes hypotensive due to post partum hemorrhage pituitary is thus more likely to suffer ischemia
Release of prolactin (PRL) is predominantly under
Tonic inhibition by the hypothalamic hormone called prolactin inhibiting hormone
Prolactin inhibiting hormone (PIH) is what
the catecholamine dopamine
What stimulates the release of prolactin
Hypothalamic thyrotropin releasing hormone (TRH)
Inhibiting action of dopamine vs. stimulating effect of TRH (on prolactn)
Inhibiting action of dopamine is stronger than the stimulating effect of TRH
Damage to the portal blood circulation which prevents dopamine and TRH from reaching the ant pit will result n
Increased release of prolactin
If dopamine reaching the ant pit decreases, then prolactin release inc
So a tumor compressing the pit stalk will cause (in relation to PRL)
hyperprolactinemia
PRL inhibits what
Ovulation in F
Spermatogenesis in M
By inhibiting gonadotropin releasing hormone (GnRH) synthesis and release from hypothalamus
Excessive prolactin release causes
Infertility
Thyroid stimulating hormone is abbreviated hoe
TSH
Thyroid stimulating hormone (TSH) is produced in the
thyrotrophs of the ant pituitary
Thyroid stimulating hormone (TSH) is AKA
thyrotropin
Thyroid stimulating hormone (TSH) - Function
Stimulates the synthesis and secretion of the thyroid hormones called Thyroxine (T4) and Triiodothyronine (T3)
Thyroid stimulating hormone (TSH) also stimulates the growth of
thyroid tissue
Can result in goiter formation under conditions of constant TSH release
Thyroid stimulating hormone (TSH) - what stimulates the secretion of it
Thyrotropin releasing hormone (TRH) from the hypothalamus
TRH (thyrotropin releasing hormone) stimualtes the release of
TSH and PRL
Leutinizing hormone is abbreviated how
LH
Follicle stimulating hormone is abbreviated how
FSH
LH and FSH stimulate
gonadal production of sex steroids which mediate reproductive function and bx
Adrenocroticotropic hormone (ACTH) stimulates
the adrenal glands to produce steroid hormones which regulate water and Na balance, inflammation and metabolism
Prolactin stimulates
breast development and milk production
Growth hormone exerts
Direct effects on tissue growth and differentiation and indirect effects through stimulation of insulin like growth factor 1 production (which mediates some of the growth and differentiation effects of GH)
Follicle stimulating hormone (FSH) is synthesized by
the gonadotropes of the ant pit
Follicle stimulating hormone (FSH) - its release is under the control of
Gonadotropic releasing hormone (GnRH) from the hypothalamus
Follicle stimulating hormone (FSH) - function
F - cause growth of follicles in ovaries
M - causes sperm maturation
Leutinizing hormone (LH) is synthesized by
Gonadotropes of the ant pit
Leutinizing hormone (LH) - its release is under the control of
Gonadotropic releasing hormone (GnRH) from the hypothalamus
Leutinizing hormone (LH) - Function
F - stimulation o fovulation, formation of corpus luteum, and estrogen and progesterone synthesis in ovaries
M - stimulation of testosterone synthesis in testes
Growth Hormone (GH) is made by the
somatotropes of the ant pit
Growth Hormone (GH) is AKA
Somatotropic hormone or somatotropin
Release of Growth Hormone (GH) is controlled by
2 opposing hypothalamic hormones that are released into the hypothalamo-hypophysial portal circulation
GHRH and GHIH
Growth hormone releasing hormone
Growth hormone inhibiting hormone (AKA somatostatin)
Growth Hormone (GH) - third regulator of GH secretion
Ghrelin - predominantly in stomach but is also secreted by the pancreas, kidney, liver and arcuate nucleus in the hypothalamus
Growth Hormone (GH) - third regulator of GH secretion - Ghrelin binds to
Growth hormone secretagogue receptor (GHS-R) = growth hormone release inducing
Growth Hormone (GH) - Function
Stimualtes protein synthesis and overall growth of most cells and tissues
Stimulates production of insulin like growth factors (IGF)
IGF AKA somatomedins
