Hypothalamic-Pituitary Relationships and Biofeedback Part 1 - DR Creamer Flashcards
The ______ ____ is the physical connection between the hypothalamus and the pituitary gland.
hypophysial stalk
Due to anatomical location, tumors in the pituitary expand and put pressure on the ____ ___.
optic nerves
The posterior pituitary is derived from neural tissue whose cells bodies are located in the hypothalamus. These nuclei are the _____ nucleus and the _____ nucleus.
supraoptic; paraventricular
The supraoptic nucleus (SON) secretes _____.
ADH
The paraventricular nucleus (PVN) secretes ____.
oxytocin
The anterior pituitary is connected to the hypothalamus by the _____-_____ ____ ____.
hypothalamic-hypophyseal portal system
The anterior pituitary secretes what 6 hormones?
ACTH, TSH, FSH, LH, GH, and prolactin.
Hormones do not appear in ____ concentration in systemic circulation from the hypothalamus because they can be ____ delivered to the anterior pituitary in ___ concentrations.
high; directly; high
The connections between the hypothalamus and posterior pituitary are ____, whereas the connections between the hypothalamus and anterior pituitary are ____ and ____.
neural; neural; endocrine
What constitutes the 3 families of the anterior pituitary?
ACTH family; TSH, FSH, LH family; GH, prolactin family.
TRH in the hypothalamus targets thyrotrophs in the APit to secrete ____.
TSH
CRF in the hypothalamus targets corticotrophs in the APit to secrete ____.
ACTH
GnRH in the hypothalamus targets gonadotrophs in the APit to secrete ____.
LH and FSH
GHRH in the hypothalamus targets somatotrophs in the APit to secrete ____.
GH
______ (____) in the hypothalamus targets somatotrophs in the APit to inhibit secretion of GH.
Somatostatin; GHIH
A PIF (such as dopamine) in the hypothalamus targets lactotrophs s in the APit to inhibit secretion of ____.
PRL (prolactin)
Elevated TRH in the hypothalamus targets lactotrophs in the APit to secrete ____.
PRL
A ____ endocrine disorder is high or low levels of a hormone due to a defect in the peripheral endocrine gland.
primary
A ____ endocrine disorder is high or low levels of a hormone due to a defect in the pituitary gland.
secondary
A ____ endocrine disorder is high or low levels of a hormone due to a defect in the hypothalamus.
tertiary
Extreme energy deficits, extreme exercise, and depression can inhibit ____ function.
GnRH
FSH and LH promotes ____ and ____ secretion in female and ____ production in males.
estrogen; progesterone; testosterone
Normal menstrual cycle depends on ___ and ___.
LH and FSH
Describe the HPG axis in females.
GnRH > LH & FSH > androgens & progestins and estrogens
Describe the HPG axis in males.
GnRH > LH & FSH > testosterone & androgen-binding protein and spermatogenesis
_____ is secreted by the Sertoli cell in males and the Granulosa cell in females and inhibits FSH synthesis in the pituitary gland.
Inhibin
____ is characterized by excessive growth of soft tissue, cartilage, and bone in the face, hands, and feet. It is caused by prolonged and excessive secretion of ____ ____ in adult life.
Acromegaly; growth hormone
Growth hormone is produced by _____.
somatotropin
Growth hormone targets the ___ and ___.
liver; bone
Growth hormone is inhibited by _____ and ___.
somatostatin; IGF-1
Growth hormone is stimulated by _____ and _____.
fasting; hypoglycemia
What are the 3 direct actions of growth hormone?
Binds directly to target cells on bones and muscle to induce cell growth (hypertrophy), cell reproduction (hyperplasia), and cell metabolism.
What are the indirect actions of growth hormone?
signals liver to produce IGF which targets almost every cell in the body to stimulate hypertrophy and hyperplasia
Describe the HPGh axis.
GHRH>GH>IGF-1.
Hypothalamus can also release GHIH which inhibits GH from being released from the APit. GH inhibits GHRH. IGF-1 inhibits GH and GHRH and stimulates GHIH.
A primary endocrine disorder affecting the HPGh axis would have low levels of ___ and high levels of ___.
IGF-1; GH
A secondary endocrine disorder affecting the HPGh axis would have ___ levels of IGF-1 and ___ levels of GH.
low; low
A tertiary endocrine disorder affecting the HPGh axis would have ___ levels of IGF-1, ___ levels of GH, and ___ levels of Ghrelin/GHRH.
low; low; low
_____ is the disorder caused by excesses in growth hormone before the closure of bone epiphyses.
Gigantism
In the fed state, the liver will produce ____ which causes mitogenesis, lipolysis, and cell differentiation.
IGF-1
When carbohydrate intake is high and protein intake is low, ___ is inhibited so the liver ___ produce IGF-1, causing lipogenesis and carbohydrate storage causing weight gain.
GH; doesn’t
When carbohydrate intake is low and protein intake is high, GH levels ____ so the liver ___ produce IGF-1, causing lipolysis, ketogenic metabolism, and diabetogenic effect.
increase; will
GH promotes lipolysis, but can also promote _____ _____.
insulin insensitivity
GH raises blood glucose by decreasing peripheral glucose uptake and stimulating hepatic _____.
gluconeogenesis
Acromegaly can be diagnosed by ____ serum GH and IGF-1 levels and ____ to suppress GH production in response to an oral load of glucose.
elevated; failure
What are the three main metabolic functions of GH?
Diabetogenic effect, increased protein synthesis and organ growth, and increased linear growth.
Growth hormone secretion increases during ___ and ___.
sleep; exercise
Growth hormone secretion increases substantially during ____ and decreases in ___ ___.
puberty; old age
Excess in GH is usually caused by a growth hormone-secreting ____ ____.
pituitary adenoma
Growth hormone levels ____ throughout the day, whereas IGF-1 levels are ____.
fluctuate; constant
Diagnosis of acromegaly requires increased serum ___, failure to suppress serum ___ during oral glucose tolerance test, and ____ enlargement on MRI.
IGF-1; GH; pituitary
Prolactin secretion begins to increase during the ___ week of pregnancy.
fifth
____ inhibits PRL.
Dopamine
PRL stimulates and maintains ____.
lactation
PRL suppresses ____, so inhibits ___ and -__.
GnRH; LH; FSH
____ decreases reproductive function and suppresses sexual drive.
PRL
Describe the HPP axis.
The hypothalamus secretes TRH which acts on the APit to secrete PRL to act on the breasts. Dopamine secreted by the hypothalamus inhibits PRL secretion from the APit. PRL stimulates Dopamine secretion for negative feedback. PRL inhibits GnRH secretion to inhibit FSH and LH secretion to the ovaries.
Estrogen, suckling, sleep, stress, and TRH all ____ PRL secretion.
stimulate
Dopamine, dopamine agonists, somatostatin, and PRL all ____ PRL secretion.
inhibit
The most common pituitary adenoma is a ____.
prolactinoma
Cushing’s disease, TSH-secreting adenoma, acromegaly, gigantism, prolactinoma, and non-functioning adenomas are all types of ______.
hyperpituitarisms
Brain damage, adenoma, non-pituitary tumors such as craniopharyngiomas, infections, infarctions such as Sheehan syndrome, autoimmune disorders, pituitary hypoplasia or aplasia, and genetic disorders can all cause _____.
hypopituitarism
The posterior pituitary gland secretes ____ and ___.
oxytocin; ADH
Describe the regulation of oxytocin secretion.
Prepro-oxyphysin is cleaved to pro-oxyphysin in the hypothalamus and transported via the hypothalamic-hypophyseal tract where it is cleaved to oxytocin combined with NPI in the PPit. Oxytocin is released from the PPit to the breast and uterus.
Oxytocin stimulates ___ _____ when stimulated by sucking and sight, sound, and smell of an infant.
milk letdown
Oxytocin stimulates ____ ____ when stimulated by dilation of the cervix or orgasm.
uterine contraction
____ is synthetic oxytocin.
Pitocin
____ causes increased milk production, whereas ____ causes milk letdown.
Prolactin; oxytocin
