(IEMR8)Neuroendocrine Flashcards
GH excess during prepubertal ages causes what symptom?
gigantism
Why are the prolactine levels low in a normal adult?
the release is tonically inhibited
If GH deficiency occurs during prepubertal time period, what are the clinical symptoms?(3-4 points)
failure to grow, short stature, mild obesity and delayed puberty
What are examples of indirect neural reuglation of endocrine function?(5 points)
What is another name for the pituitary?
hypophysis
When consideirng the vasculature of the pitutiary, the efferenet veins drain from the anterior pituitary into the petrosal and then what structure(s)?
cavernous sinuses
What portion of the pituitary gland develops from the evagination of ectoderma cells of the oropharynx?
anterior lobe
Somatostatin +/- prolactin secretion?
(-)
Somatotrophs make up what percentage of the anterior pituitary gland?
20%
What overrides the basal feedback mechanisms in the brain?
daily rhythms
The gene required to synthesize the β-subunit of LH and the β-subunit of FSH are the same or different?
They’re the same
Prolactin levels are increased by what in both sexes?(2 points)
stress and nipple stimulation
Dopamine Antagonist +/- prolactin secretion?
(+)
Regulation of endocrine function occurs through what general type of mechanisms?(3 points)
neural, substrate and indirect
GH declines at what age?
middle and old-age
Does hypoglycemia stimulate or inhibit GH secretion?
stimulate
Prolactin +/- prolactin secretion?
(-)
What lobe of the pitutiary gland is an extension of the diencephalon?
posterior pituitary
Prolactin is +/- by estrogens(pregnancy)?
stimulated
The evagination of the ectodermal cells of the oropharynx is referred to as what?
Rathke’s pouch
GH secretion stimulated or inhibited by increased FFA?
inhibited
Is the optic chiasm always anterior or always posterior?
anterior
In anterior pituitary cells, the primary products of enzymatic cleavage of the POMC, prohormone are what hormones?(2 points)
ACTH and β-endorphins
What type of prolactin deficiency of excess can cause failure to lactate?
prolactin deficiency
What hormone stimulates the release of TSH?
TRH, synthesized and release by the hypothalamus
What i sthe prime physiological effect of prolactin?
milk production in lacting females
GH secretion +/- by arginine?
(+)stimultated
How does prolactin affect ovulation?
inhibits ovulation
ADH deficiency causes what?
diabetes insidpidus which could be either nephrogenic or central
If plasma osmolality is low, urine osmolality is what?
low
basal secretion, chrnological activity and all other layers of control the brain uses as an endocrine organ?
stress
What specfic type of cell synthesize and secrete growth hormone?
somatotrophs
If plasma osmolaity is low, what do the kidneys want to do? What does this tells you about the urine osmolaity?
The kidneys wants to exctrete water, therefore, the urine osmolaity should drop
Does lactogenesis occur in the absence of pregnancy?
yes
What specific type of cells in the anterior pituitary synthesize and secrete prolactin?
lactotrophs
The lumen of the evagination of the floor of the third ventricle of the brain closes as the side fuse to form what?
neural stalk
What are examples of the direct neural regulation of endocrine function?(2 points)
Posterior pituitary secretion of oxytocin and antidiuretic hormone to its target site and adrenal medulla release of epinephrine and norepinephrine to its target site.
The infundibular system with the posteior lobe of the pittuiary gland is referred to as what?
neurohypophysis
The secretion of FSH is inhibited by what?
inhibin
What stimulates the release of GH?
hypothalmic GHRH
Craniopharyngiomas is very common in what general age group?(common name)
children
What hormone action stimulates androgen synthesis in the thecal cells of the ovarian follicle?
LH
GH release levels off at what age?
adult level
Most of the anterior pituitary cells are of what larger category cell type in that particular area?
acidophils
The abducens nerve innervate what structure?
lateral rectus
What hormone stimulates the release of ACTH?
CRH, synthesized and release by the hypothalamus
What hormone is needed for efficiency milk delivery?
oxytocin
Rathke’s pouch, during development, is eventually pinched off from the oral cavity and becomes seperated by what structure of teh skull?
sphenoid bone
How does the ingestion of haloperidol affect dopamine levels?
It increases dopamine levels
Breast feeding -/+ prolactin secretion?
stimulates
What are the main effects of SIADH?(2 points)
decreased plasma osmolality and hyponatremia
What are the causes of GH deficiency?(4 points)
hypothalmic problem, primary pituitary probelm, failure to generate somatomedins in target(primarily the liver) or a receptor or post-receptor probelm
What is the action of LH?(2 points)
promotes androgen synthesis in Leydig cells of the testia and thecal cells of the ovarian follicle
What is particularly important about the circumventricular organs?
The blood brain barrier is compromised
IGF acts thorugh what group of receptors?
tyrosine kinase receptors
When considering the regulation of prolactin, how does increase prolactin affect the hypothalamus?(2 points)
stimulates the hypothalmus to produce dopamine which inhibits the anterior pituitary
What lobe of the pituitary gland is a circumventricular organ?
posterior lobe of neurohypophysis
Does GH stimulate the conservation of protein or the breakdown of protein?
conservation of protein
Prolactin secretion is inhibited or stimulated by dopamine?
inhibited
What is the action of FSH?
gamete development; acts on sertoli cells in male and granulosa cells in female
What happens if you perform an hypophysis? What hormones would be affected?
all of the anterior pituitary hormones
Stress +/- prolactin secretion?
(+)
What is the distribution of water as a result of SIADH?
2/3rd goes into the cell and 1/3rd goes into the plasma
When some cells from Rathke’s pouch are left behind, forming tumors, these are referred to as what?(Neurology)
craniopharyngiomas
GH secretion stimulated or inhibited by stress?
stimulated by stress
The 6 major hormones synthesized and secreted by the anterior pituitary gland are what type of hormones: steroid, peptide or tyrosine derivative?
peptide/proteins
What are the post-puberal affects of GH deficienecy?(2 points)
metabolic probelms and increased insulin sensitivity
Sleep +/- prolactin secretion?
(+)
The trochler nerve innervate what structure?
superior oblique muscle
Inhibin is relased by what cells?(2 points)
Sertoli cells in males and granulosa cells in females
How does GH affect protein and glucose in the body?
GH protects protein from being broken down in the body and it increase glucose level in the blood
GH secretion stimulated or inhibited by exercise?
stimulated by exercise
What subunit of TSH, FSH and LH are unique to each of them and confer biologic activity?
β-subunit
How does the prolactin level change for a person who is stressed out?
It would increase from 20 to 100
What portion of the pitutiary gland develops from neural crest cells as a downward evagination of the floor of the third ventricle of the brain?
posterior pituitary gland
What hormones are synthesized and secrted by the anterior pituitary gland?7
prolactin, growth hormone, follicle stimulating hormone lutenizing hormone, adrenocorticotropic hormone and thyroid stimulating hormone
What hormone stored in the posterior pituitary is a major regulator of osmolaity?
ADH
The β-subunit of hCG and the β-subunit of LH are the same or different?
they’re different
GH secretion +/- by obesity?
(-)inhibited
What hormones are stored in the posterior pituitary?(2 points)
oxytocin and ADH
Where does glycosylation of the TSH, FSH and LH hormones take place during their synthesize?
It occurs in the Golgi
How do somatomedina affects the anterior pituitary in the regulation of GH?
It inhibits the anterior pituitary
The upper part of Rathke’s pouch forms what part of the anterior pituitary gland?(technical name of a structure)
pars tuberalis
What is the most important transcription factor invoeld in the differnetiate of different cell types of the anterior lobe of the pituitary gland?(Hint:Rathke’s Pouch Stem Cell
Pit1
What are the subdivisions of the neural regulation of endocrine function?(2 points)
indirect and direct
If a patient’s trochlear nerve is damaged, what is the presentation?
downward, outward gazing due to the unopposed actions of superior oblique and lateral rectus
The indirect actions of GH are facilitated through what hormone?
IGF-1
What is the primary hypothalmic parathryoid inhibition hormone?
dopamine
ACTH release is stimulate by what?
hypothalmic CRH
If plasma osmolaity is high, the kidneys wants to do what to compensate?
save water, therefore raise the urine osmolaity to lose more of the electrolytes and save water
What two structure forms the infundibular stem of the neurohypophysis?
neural stalk with the median eminence
What are the actions of TSH(2 points)
stimulates the synthesis and secretion of thyroid hormones and stimualtes thyroid gland growth
What hormone promote thyroid gland growth?
TSH
What are the symptoms of acromegaly?(5 points)
tongue enlargement, incresed non-fused bone growth in the face, fingers, jaw, organomegaly and insulin resistance and glucose intolerance
How do you treat nephrogenic diabetes insidpidus?
you provide an ADH analogue
Does GH excess have the same affect different affect regardless on the time period it occurs?
No, prepubertal effects or different than postpubertal affects
GH secretion inhibited or stimulated by pregnancy?
inhibited
What hormones are secreted and synthesized by the posterior pituitary gland?
none
Chronic stress is associated with an increase release of what hormone?
cortisol
The greatest release of GH takes place during what part of the day?
slee: stage III and IV
What happens if you perform a stalk section?
remove hypothalmic influences
The neural crest cells that develop from a downware evagination of the floor of the third ventricle forms a pouch which lumen closes of at the sdies to form the neural stalk while the upper portion of the pouch forms a recess in the floor of the third ventricle known as what?
median eminence
What hormone is responsible for lactogenesis?
prolactin
What subunit of TSH, FSH and LH are identical to eachother?
α-subunit
What cranial nerves are in the cavernous sinus?
II, IV and VI
A major stimulator for ADH is what?
a decrease in plasma osmolality
What is lactogenesis?
milk production in response to suckling
What endocrine roles does the brain play?(5 points)
hormone production, chronological control, stress responses, hormone metabolism and hormone targets
What prohormone can give rise to many products?
Pro-Opio-Melanocortin Family(POMC)
What are the actions of oxytocin?(3 points)
needed for efficicent milk delivery, uterine contractions, involved in sexuality
What nucleus in the hypothalmic-pituitary axis is very important in the circiadian rhythm?
suprachiasmatic nucleus
GH secretion is stimuated or inhibited by decreased FFA?
stimulated
What stimulates the release of FSH?
GnRH
There is a direct connection between the light and what nucleus in the hypothalamus?
suprachiasmatic nucleus in the hypothalamus
What circumventricular organ responds to light?
pineal gland
The α-subunit of hCG and the α-subunit of TSH are the same or different?
they’re the same
How many genes are required to synthesize LH?
two genes
How do you differentiate the anterior pituitary and the posterior pituitary on an image or on a gross structure?
The posterior pituitary looks white on an image and via gross structure and the anterior pituitary doesn’t look white due to the fact that is mainly has blood vessels and the posterior pituitary mainly has nerve filaments
ADH binding to V1 receptors causes what responses?
stimulates contraction
The primary capillaries of the hypothalamus sit in what structure?
median eminence
The gene required to synthesize the α-subunit for TSH and the α-subunit of LH are the same or different?
they’re different
Melatonin synthesis occurs in the day time or in the night time?
night time
During pregnancy, what hormones causes growth and development of mammary alveoli?
estrogen and progesterone
During puberty, what induces a large burst in GH?
sex steroids
GH secretion stimulated or inhibited by growth hormone?
inhibited
Why shouldn’t we worry about growth of a women during pregnancy, due to the fact that pregnancy inhibits GH hormone release?
the placenta synthesizes and produces its own type of growth hormone
A person with a prolactinoma is more likey to be hypoglycemic or hyperglycemic?
hypoglycemic
All of the hypothalamic hormones get released to what structure?
median eminence
What hormones are secreted by the pituitary gland?
oxytocin and ADH
ADH interacts with what receptors in the kidney?
high affinity V2 receptors
hCG is a peptide hormone or a steroid hormone?
peptide hormone or more specifically a glycoprotein
Dopamine antagonist are commonly used as what type of general psychological medication?
anti-psychotics
What hormonal changes would occur if a stalk section was performed?(6 points)
You lose FSH, LH, ACTH and TSH. You lost most of GH. There will be an increase in prolactin.
What is a secondary stimulus to ADH release?
a large decrease in blood volume
How does TRH affect prolactin release?
It stimulates prolactin release
ACTH action?(2 points)
stimulates adrenal growth and cortisol production
GH secretion +/- by fasting/starvation?
stimulated(+)
What organ in the circumventicular organs plays a very important role in the control of water and salt intake?
subfornical organ
DA agonist -/+ prolactin secretion?
(-)
GH secretion stimulated or inhibited by pubertal hormones?
stimulated
How does an increase in GHRH affect the hypothalamus?
It inhibits the hypothalmus from synthesizing and relasing GHRH
What hormones at puberty causes proliferation and branching of the mammary ducts?(2 points)
estrogen and prolactin
What kind of hormone deficiency of excess can cause a adrenocortical pituitary hypofunction?
prolactin excess
If plasma osmolaity is normal, urine osmlaity reflects what
hydration status
GH excess effects during a postpubertal age causes what?
acromegaly
TSH secretion is stimulated by what?
hypothalmic TRH
What inhibits the release of GH?
hypothalmic somatostatin
Does GH deficiency always have the same affect regardless of the timeline?
No, the affects are very different if it is prepubertal or post-pubertal
What are the types of neuroendocrine disorders?(3 points)
primary, secondary and tertiary
What are the relative levels of prolactin in a normal adult?
low
GH secretion inhibited or stimulated by somatostatin?
inhibited
Does hyperglycemia inhibit or stimulate GH release?
inhibit
What type of receptors in the vascultaure does ADH bind?
V1 receptors
ADH interactions with V2 receptors in the kidneys results in what?
an increase in water channels (AQP2)
What hormones stimulate the production of milk during pregnancy?(2 points)
estrogen and progesteron INHIBIT the production of mik during pregnancy
Prolactin deficiency results in what issue?
failure to lactate
How does growth hormone affect the hypothalamus(2 points)
it stimulates the hypothalmus to synthesize and release somatostatin which inhibits the anterior pituitary
If plasma osmolaity is high, urine osmolaity is what?
high
How similar are the growth hormone, prolactin and hPL/hCS?
they’re simliar hormones (75% homology and 80% homology, respectively speaking)
Thyrotropin Releasing Hormone +/- prolactin secretion?
(+)
What are the pro-metabolic affects of GH?(2 points)
increase uptake of amino acids and stimulate proteins synthesis and increase organ size
What can prolactin excess cause?(5 points)
galactorrhea, infertility and other pittuiary hypofuctions like adrenocortical and thyroid
How does growth hormone affect linear growth?
It increases linear growth during pubertal growth spurt
How is GH diabetogenic?(5 points)
It results in the increase of blood glucose concentration, it decrease muscle and adipose tissue glucose uptake and it increase lipolysis in adipose tissue
GH secretion stimulated or inhibited by somatomedins?
inhibited
Does GH stimulate the conservation of fat or the lipolysis of fat?
lipolysis of fat
What percentage loss of blood volume is sufficient to increase the release of ADH?
10-20% loss of blood volume
Luteinizing hormone release is stimulated by what?
GnRH
How do somatmedins affects the hypothalamus in the regualation of GH?(2 points)
it stimulates the hypothalmus to synthesize somatostatin which inhibits the anterior pituitary
ADH excess causes what?
SIADH
What circumventricular organ is very important when you consider pH, breathing, respirtaion and cardiovascular control?
Area Postrema
How does the prolactin level change for a person who has a prolactin secreting tumor?
It would go from like 20 to 1000
What happens if their is a pitutiary tumor in the sella turcia large enough to compress the cavernous sinus?
The three nerve, II, IV and VI could be compressed leading to mild to significant vision probelms.
What neurlogical disease does Dopmaine treat?
Parkinson’s disease
What are the circumventricular organs?6-8
median eminence of the hypothalamus, neurohypophysis, subfornical organ, area postrema, pineal gland, choroid plexus, organum vasculosum of the Lamina Terminalis and subcommisural organ
Oxytocin release is stimulated by what physial manipulations?(3 points)
nipple stimulation, nipple suckling and cervical stretch
What general types of actions does GH exert?(2 points)
direct and indirect
