Endocrinology Part 1 (Hypothalamus, Pituitary, and Pineal Gland) Flashcards
Controls flow of information between cells and tissues by releasing hormones
ENDOCRINE SYSTEM
Substances secreted by endocrine gland that conveys information to its target cells
HORMONES
All hormones will act on all cells
F (Not ALL hormones will act on all cells; requires
appropriate cell receptor)
Chemical signals produced by specialized cells secreted into the bloodstream and carried to a target tissue (with specific receptor)
Hormones
Generally, act at sites distant from their place of origin
Ex: some pituitary hormone acts on thyroid gland,
gonads, adrenal gland
Hormones
Regulates cells and organs to maintain homeostasis
Ex:
ADH – regulates water homeostasis
Aldosterone – regulates Na homeostasis
Hormones
hormone concentrations are regulated by?
feedback mechanisms/loop
Actions of hormones
1) Regulatory substance
2) Controls body functions
TYPES OF HORMONE ACTION
ENDOCRINE
PARACRINE
AUTOCRINE
JUXTACRINE
INTRACRINE
Acts at a distant site from their place of origin
endocrine
Acts on the neighboring cells
paracrine
Acts on its self
Ex: hormone produced by hypothalamus will act on hypothalamus
autocrine
Remain intact/bound to cell membrane; acts on
adjacent cells by cell-to-cell contact with cell
receptors
Juxtacrine
how does juxtacrine acts on adjacent cells
cell-to-cell contact
Acts inside the cells (non-producible/released)
intracrine
CHEMICAL COMPOSITION/NATURE OF HORMONES
PEPTIDES & PROTEINS
STEROID
AMINO ACID DERIVATIVES (Amines)
FATTY ACID DERIVATIVES
chemical composition of water soluble hormones
PEPTIDES & PROTEINS
chemical composition of hormones that do not require carrier (transport proteins)
PEPTIDES & PROTEINS
Nature of majority of the hormones
PEPTIDES & PROTEINS
chemical composition of hormones that is synthesized and stored within cells
PEPTIDES & PROTEINS
chemical composition of hormones that is stored inside the cell where they are produced
PEPTIDES & PROTEINS
Example of hormone with peptide & protein nature
GH – produced by pituitary gland; cells that
produce GH will synthesize GH but they are
retained inside the cell; only released when the
body needs GH
Steroid hormones regulates?
sexual dev’t and characteristics
Precursor of steroid hormones
cholesterol (a sterol)
Example of steroid hormones
Sex hormones
- testosterone
- progesterone
- estrogen
- androgen
Have similarity with peptide & steroid in nature
Amino acid derivatives (amines)
Example of amino acid derivatives
Catecholamine, Thyroid hormone
Hormone with fatty acid derivative nature includes?
eicosanoids
Example of hormones with fatty acid derivative
prostaglandins (procoagulants – in relation with
homeostasis; thromboxane A2)
HORMONE TYPES ACCDG TO TRANSPORT
FREE
BOUND (to transport proteins)
Nature of free hormones
Peptides hormones (water soluble)
Exceptions in free hormones
Some are water soluble which do not require transport proteins. However, there are some that REQUIRES TRANSPORT PROTEINS:
- GH
- Insulin-like Growth Factor 1 (IGF-I)
- Insulin-like Growth Factor 2 (IGF-II)
- Vasopressin
- Oxytocin
Enumerate bound proteins
Steroid & Thyroid Hormones
* Albumin
* Corticosteroid-binding globulin (CBG)
* Sex hormone-binding globulin (SHBG)
* Thyroxine-binding globulin (TBG)
Amines (catecholamines)
* Serum proteins
* TBG
T/F
Both FREE and BOUND proteins have hormonal activity
F
*only FREE hormones have hormonal activity
*transport proteins must detach to bound hormones to exhibit hormonal activity
MAIN HORMONE PRODUCING GLANDS
HYPOTHALAMUS
PITUITARY
PINEAL
THYROID
PARATHYROID
ADRENAL
PANCREAS
OVARIES
TESTIS
Hypothalamus is responsible for these activities
1) Sleep
2) Thirst
3) Mood
4) Hunger
5) sex drive
Gland that secrete regulatory hormones (releasing, inhibitory)
hypothalamus
2 types of regulatory hormones produced by hypothalamus
- releasing hormones
- inhibitory hormones
Controls other glands by production of
stimulating hormone (tropic hormones)
Pituitary (master gland)
Pituitary gland produce hormones that triggers?
growth
T/F
Majority of pituitary hormone acts on another gland
T
Action of pituitary to stimulate thyroid gland to produce thyroid hormones
Release thyroid-stimulating hormone (TSH)
Gland that secretes melatonin (for sleep cycle)
Pineal gland
Gland that secretes hormones assoc. with calorie burning and heart rate
Thyroid gland
Secretes hormone that controls calcium and phosphate homeostasis
Parathyroid gland
Secretes sex drive hormones and stress hormones
Adrenal gland
Secretes insulin (for glucose homeostasis)
Pancreas
Gland that is both an exocrine and endocrine? what is the action?
Pancreas
- Exocrine – secretes enzymes
- Endocrine – secretes hormones
Hormones secreted by ovaries
- female sex hormones (progesterone & estrogen)
- testosterone
Hormones secreted by testes
testosterone
Amount of substance in a system regulates its own concentration
NEGATIVE FEEDBACK
Increased or decreased hormone levels will stimulate hormone inhibition or production, respectively
NEGATIVE FEEDBACK
Hormones released by an endocrine gland induces
more stimulating hormones to be released
POSITIVE FEEDBACK
The more hormone is secreted, the more action is stimulated
POSITIVE FEEDBACK LOOP
associated glands in ultrashort feedback loop
Hypothalamus and pituitary
associated glands in short feedback loop
Pituitary and target gland
associated glands in long feedback loop
Hypothalamus, pituitary, and target gland
Majority of endocrine functions are regulated through this gland
pituitary gland
Secretion of pituitary gland is regulated or controlled by?
hypothalamus
Hormone production involves 2 glands in CNS:
hypothalamus, pituitary
Glands other than hypothalamus & pituitary
Peripheral glands
Hormone secretion by peripheral glands is stimulated by these glands
hypothalamus & pituitary
Stimulating thyroid gland to produce its hormone is an example of what feedback loop
negative
Stimulating oxytocin production is an example of what feedback loop
positive
what is the term when hypothalamus, pituitary, and thyroid gland is involved in the process?
Hypothalamic pituitary thyroidal axis
Explain the events in hypothalamic pituitary thyroidal axis
1) Hypothalamus will secrete regulatory (releasing) hormones for thyroid → thyrotropin-releasing hormone (TRH).
2) TRH directly acts on pituitary gland to stimulate tropic hormone → thyroid-stimulating hormone (TSH) or thyrotropin.
3) TSH will stimulate thyroid gland to produce thyroid hormone.
4) Continuous process to increase thyroid hormone until it becomes in excess.
5) Thyroid gland will send signal to hypothalamus to stop production.
6) Hypothalamus will inhibit TRH release (following
processes will not continue).
✓ If in cases of low thyroid hormone: thyroid
gland will send signal to hypothalamus to start
production of TRH (further processes will follow)
✓ Equalized thyroid hormones will send another
feedback to stop.
substance released by hypothalamus to stimulate thyroid gland secretion of thyroid hormones
thyrotropin-releasing hormone (TRH)
function of TRH
directly acts on pituitary gland to stimulate tropic
hormone → thyroid-stimulating hormone (TSH) or
thyrotropin
function of TSH
stimulate thyroid gland to produce thyroid hormone
signal is sent by a peripheral gland (target gland) to this gland to stop production of hormones in cases of excess production? what is the action?
hypothalamus
inhibit TRH release (or other releasing hormones required)
Acts on uterus during labor involving uterine contraction (Ferguson reflex)
oxytocin
uterine contraction is aka
Ferguson reflex
mechanism of oxytocin
The more oxytocin, the more contraction
The more the contraction, the more it stimulates oxytocin production
Until it reaches parturition (giving birth)
2 MODULATION OF HORMONE LEVEL
HYPOTHALAMIC-PITUITARY-END ORGAN (PERIPHERAL GLAND) SYSTEM
FREE-STANDING ENDOCRINE GLAND SYSTEM
Regulation is CNS input
HYPOTHALAMIC-PITUITARY-END ORGAN (PERIPHERAL GLAND) SYSTEM
Regulation is Varied input
FREE-STANDING ENDOCRINE GLAND SYSTEM
Enumerate activities under HYPOTHALAMIC-PITUITARY-END ORGAN (PERIPHERAL GLAND) SYSTEM
- Regulation: CNS input (signal sent by peripheral gland to the hypothalamus)
- Hypothalamus (Releasing hormone)
- Pituitary (Tropic/Stimulating hormone)
- Peripheral Glands (Hormone)
- Target cell (Effect) with appropriate cell receptor
Enumerate activities under FREE-STANDING ENDOCRINE GLAND SYSTEM
- Regulation: Varied Input (depends on target cell or substance that is regulated by the hormone)
- Free-Standing Endocrine Gland (Hormone)
- Target cell (Effect) with appropriate cell receptor
Modulation wherein hormone concentration depends on the substance that it regulates
FREE-STANDING ENDOCRINE GLAND SYSTEM
example hormones of FREE-STANDING ENDOCRINE GLAND SYSTEM
Parathyroid hormone – Ca and PO4 homeostasis
Insulin – glucose homeostasis during ↑ GLU
Mount a response to a hormone
TARGET ORGAN
Express appropriate cognate hormone receptor/
appropriate cell receptor
TARGET ORGAN
3 TYPES OF HORMONE RECEPTORS
Cell Surface Receptors
Intracellular Receptors
Multiple Receptors
Cell Surface Receptors
Insulin
GH
PRL
Leptin
Catecholamine
hunger hormone secreted by
adipocytes/fat cells; mechanism
Leptin
Fat individuals – frequent
hunger promotion due to ↑
Adipocytes (↑ Leptin)
Intracellular Receptors
Steroids
Thyroid hormones
Multiple Receptors
Estrogen
Progestins
location of hypothalamus
walls and floor of 3rd ventricle (above pituitary gland)
hypothalamus is connected to posterior pituitary gland by this structure
pituitary stalk (infundibulum)
Majority of the hormone produced by this gland has direct effect on pituitary gland
hypothalamus
Hypothalamus is part of this feedback mechanism
NEGATIVE feedback loop
Releasing hormones produced by hypothalamus
- Thyrotropin-releasing hormone (TRH)
- Growth hormone-releasing hormone (GHRH)
- Gonadotropin-releasing hormone (GnRH)
- Corticotropin-releasing hormone (CRH)
- Prolactin-releasing factor (PRF)
Inhibiting hormones produced by hypothalamus
- Prolactin-inhibiting factor (PIF)
- Vasopressin (inhibit urine output)
- Oxytocin
- Somatostatin
Pituitary gland is aka
hypophysis (meaning: below the hypothalamus)
pituitary literally means
“spit mucus”
(believed in the past that the mucus secreted is necessary for growth)
Pituitary gland is previously referred to as
master gland
(they believed that no pituitary, no growth)
Pituitary gland is presently referred to as
transponders
Reason why pituitary gland is characterized as transponders
Translate neural/CNS input (signal sent by
peripheral gland) from hypothalamus into a
hormonal product
location of pituitary gland
base of the skull in the pocket of the
sphenoid bone (sella turcica/Turkish saddle)
depression of sphenoid bone is aka
sella turcica/Turkish saddle
Largest portion of pituitary gland
Anterior pituitary gland (Adenohypophysis)
Function of anterior pituitary gland (adenohypophysis)
Secretes and produce hormones
aka Posterior pituitary gland
Neurohypophysis
aka Anterior pituitary gland
Adenohypophysis
aka Intermediate lobe
Pars intermedialis
function of posterior pituitary gland
Only secretes
ADH and oxytocin storage
Poorly developed; no function
Mistaken as nodules or benign cyst
Intermediate lobe (Pars intermedialis)
Hormones produced in anterior pituitary gland
GH
PRL
LH, FSH
TSH
ACTH
Specialized cells for GH production
Somatotrophs
Specialized cells for PRL production
Lactotrophs
Specialized cells for LH, FSH production
Gonadotrophs
Specialized cells for TSH production
Thyrotrophs
Specialized cells for ACTH production
Corticotrophs
2 types of hormones secreted by anterior pituitary gland
Direct effector hormones
Tropic/stimulating hormones
types of hormones secreted by anterior pituitary gland that act on peripheral tissues
Direct effector hormones
Example of direct effector hormones
GH, prolactin
types of hormones secreted by anterior pituitary gland that acts on another endocrine gland
Tropic/stimulating hormones
Examples of Tropic/stimulating hormones
LH, FSH, TSH, ACTH
aka GH
SOMATOTROPIN
hormones that are structurally similar with each other
GH
Prolactin
Human placental lactogen
Most abundant hormone secreted by pituitary gland
GH
GH directly acts on this organ? what is produced?
liver
stimulate liver to produce growth factors
essential for LINEAR/LONGITUDINAL GROWTH
growth factors
A peptide hormone but an exception as it requires
transport protein (IGFBP-3)
GH
GH production is heavily modulated by other factors such as
Ghrelin
An enteric hormone, potent stimulator of GH receptors
Ghrelin
Ghrelin is responsible for?
- Nutrient sensing
- Appetite
- Glucose Regulation
1/3 of the total pituitary weight (most abundant cell in anterior pituitary gland)
Somatotrophs
release of GH is STIMULATED by this substance produced by hypothalamus
GHRH
release of GH is INHIBITED by this substance produced by hypothalamus
Somatostatin
manner of GH secretion? what is the interval? what is the most reproducible peak?
pulses
Ave. pulse interval: 2-3 hrs
Most reproducible peak: Onset of sleep
Method for GH measurement
Chemiluminescence Immunoassay
GH Reference Value
<7 ng/ml (fasting state)
GH secretion is STIMULATED by these modifiers
- Sleep (deep sleep) *major contributor
- Exercise
- Physiologic stress
- Amino acids (arginine)
- Hypoglycemia
- Sex steroids (estradiol)
- a-agonists (norepinephrine)
- b-blockers (propranolol)
GH secretion is INHIBITED by these modifiers
- glucose loading
- emotional/psychogenic stress
- nutritional deficiencies
- insulin deficiency
- thyroxine (T4) deficiency
- b-agonist (epinephrine)
- a-blockers (phentolamine)
In hypoglycemia, GH secretion is increased/decrease? reason?
increased GH
to increase GLU
In exercise, GH secretion is increased/decreased? reason?
increased GH
since it utilizes energy, requires GH to increase GLU
In glucose loading, GH secretion is increased/decreased? reason?
inhibited GH
no need to increase GLU
Actions of GH
1) amphibolic
2) effective transition from fed state → fasting state
3) insulin antagonists
4) promotes hepatic gluconeogenesis
5) stimulates lipolysis
explain GH as an amphibolic hormone
directly influences both anabolic (req. energy) and
catabolic (prod. energy, still req. energy) processes
Actions of GH which increases glucose
- insulin antagonists
- promotes hepatic gluconeogenesis
- stimulates lipolysis
associated with GH, these are GF secreted by liver
structurally similar to insulin
Somatomedins
aka Somatomedins
Insulin-like Growth Factors (IGF)
major GF induced by GH
Somatomedin C (IGF-1)
Biologic amplifier of GH levels (most potent)
Somatomedin C (IGF-1)
Transport protein of somatomedin C (IGF-1)
Insulin-like Growth Factor Binding Protein-3 (IGFBP-3)
↑ GH is seen in
- Acromegaly
- Gigantism
- Chronic malnutrition
- Renal disease
- Cirrhosis
- Sepsis
↓ GH is seen in
- Idiopathic GH deficiency (among children)
- Pituitary Adenoma (among adults)
↑GH + closed epiphyseal plate
diffused overgrowth/lateral
Acromegaly
↑GH + open epiphyseal plate
linear/longitudinal growth
Gigantism
Pathologic or autonomous GH excess – unregulated GH regardless of GHRH presence or absence
Acromegaly
Progressive enlargement of hands, feet, facial bones, mandible bones of the skull
Acromegaly
Manifestations of acromegaly
- Diffused growth
- Glucose intolerance/overt diabetes (↑ GH = ↑ Glu)
- Excessive sweating
- Heat intolerance
- Advanced cases: significant gaps between teeth
GH level in acromegaly
> 50 ng/ml
TESTS for Acromegaly
SCREENING: Somatomedin C (IGF-1) measurement
CONFIRMATORY: OGTT
Patient preparation for OGTT (test for acromegaly)? What is the effect?
overnight fasting
Normally: decreased Glu = increased GH
Glucose Load administered for OGTT (test for acromegaly)? What is the effect?
100g oral GL
Normally: increased Glu = decreased GH (or undetectable)
Acromegaly = still INCREASED GH
Blood collection interval for OGTT (test for acromegaly)
thrice (0 hr, 1hr, 2hr)
*all have increased GH in acromegaly
another case that has ↑ IGF-1 aside from acromegaly; autonomous IGF-1 production
Hepatoma (liver cancer)
TESTS for GH deficiency
Insulin-induced Hypoglycemia
Combination infusions of GHRH and L-arginine
L-arginine + oral Levodopa (L-DOPA) infusion
previous gold standard for GH deficiency testing? what is the normal and abnormal results?
Insulin-induced Hypoglycemia
Normally, in hypoglycemia: ↑ GH (to ↑ Glu)
GH deficiency: ↓ GH (regardless of ↑/↓ Glu)
Reference interval for GH deficiency tests
3-5 ng/ml (less likely to have GHD)
Value for GH deficiency test that signifies GHD
<3 ng/ml
aka PROLACTIN
Stress hormone
has vital function in reproduction, lactation initiation and maintenance
prolactin
release of prolactin is STIMULATED by these substances produced by hypothalamus
TRH
Estrogen
release of prolactin is INHIBITED by this substance
Dopamine (Prolactin Inhibitory Factor)
what is unique in regulation of prolactin
tonic inhibition
(NO direct signaling to hypothalamus to stop
production; instead, it produce dopamine)
Increased PRL is seen in
Medications
Tumors (prolactinoma)
Trauma
Inflammation
Hypogonadism
Result of increased PRL in postpartum lactating women, no ovulation or menstruation (↓ FSH & LH - necessary for ovulation)
hypogonadism
Reference value of PRL in male and female
Male: 1-20 ng/ml
Female: 1-25 ng/ml
Highest PRL level is during
Sleep (4pm – 8am)
–> Other ref.: 8pm to 10pm
Method for PRL measurement
Immunometric assay
Autonomous secretion of prolactin due to pituitary tumor
Prolactinoma
Most common type of functional pituitary tumor
Prolactinoma
PRL level in prolactinoma
> 150 ng/ml
If PRL level is >200 ng/ml, it causes?
anovulation, cessation of ovulation
Manifestation of prolactinoma
Elderly: hypogonadism, osteoporosis
Premenopausal women: amenorrhea,
infertility, galactorrhea, breast discharge
Men/Postmenopausal women: Pituitary
mass, Reduced libido, Erectile dysfunction
normal prolactin but lactating; common
among women who had several pregnancies
Idiopathic Galactorrhea
medications that can cause hyperprolactinemia? give the examples
Dopamine antagonists
- Phenothiazines
- Butyrophenones
- Metoclopramide
- Reserpine
- Tricyclic antidepressants
- Alpha-methyldopa
Enumerate Tropic/Stimulating Pituitary Hormones
Gonadotropins (FSH/LH)
Thyroid-Stimulating Hormone (TSH)/Thyrotropin
Adrenocorticotropic hormone (ACTH)
Markers in diagnosing fertility and menstrual cycle disorder
Gonadotropins (FSH/LH)
function of FSH and LH in male
FSH – spermatogenesis
LH – helps Leydig cells to prod. testosterone
function of LH in female
ovulation
Diagnosis clue of premature menopause
↑ FSH
↑ FSH, LH indicates?
Post-menopause (↓ estrogen)
Estrogen regulation is under this loop? give the process?
NEGATIVE feedback loop
- ↓ estrogen signals hypothalamus to ↑ estrogen
- Hypothalamus will ↑ GnRH
- GnRH will directly act on pituitary gland
- Pituitary gland will secrete FSH & LH
- FSH & LH will act on gonads to produce estrogen
Problem in post-menopausal women
Estrogen can no longer be produced due to ruptured gland in ovaries.
Even ↑ FSH, LH: there will be no estrogen production
Regulates thyroid hormone production
Thyroid-Stimulating Hormone (TSH)/Thyrotropin
Main stimulus for uptake of iodide by thyroid gland
Thyroid-Stimulating Hormone (TSH)/Thyrotropin
required by thyroid gland for production (TSH aids in uptake of iodine into the follicular cells of thyroid gland)
iodine
Acts to increase the number and size of follicular cells of thyroid gland
Thyroid-Stimulating Hormone (TSH)/Thyrotropin
Produced in response to ↓ plasma cortisol
Adrenocorticotropic hormone (ACTH)
Regulator of adrenal androgen synthesis
Adrenocorticotropic hormone (ACTH)
hormone that requires EDTA plastic tube for collection
Adrenocorticotropic hormone (ACTH)
Specimen for ACTH
EDTA (plastic tube)
*glass tubes – not used; ACTH adheres to the wall of glass (false ↓ ACTH)
Best time to collect specimen for ACTH
8-10 am (ACTH exhibits diurnal variation)
↑ conc. – 6-8 am
↓ conc. – 6-11 pm
Conditions associated with HYPOPITUITARISM
Panhypopituitarism
Monotropic Hormone Deficiency
Sheehan’s Syndrome
Kallmann Syndrome
Complete pituitary function loss (all hormones secreted by pituitary gland is decreased/no function)
Panhypopituitarism
Loss of 1 single pituitary hormone
Monotropic Hormone Deficiency
Postpartum ischemic necrosis of pituitary following a complicated delivery; Failure to lactate
Sheehan’s Syndrome
aka Kallmann Syndrome
Idiopathic hypopituitarism (there is loss of pituitary functions)
Never produce but secretes hormones from hypothalamus
POSTERIOR PITUITARY GLAND
Storage region for vasopressin and oxytocin (both produced from the supraoptic and paraventricular nuclei of hypothalamus)
POSTERIOR PITUITARY GLAND
Synthesized by paraventricular nuclei of hypothalamus
OXYTOCIN
Critical role of oxytocin
lactation
Major role of oxytocin
labor & parturition → positive feedback loop
o Uterine contraction (Ferguson reflex)
how is oxytocin released
neural stimulation of touch receptors (birth canal, uterus and breasts)
has structure similar with oxytocin
VASOPRESSIN /ADH/Arginine vasopressin
Regulates water homeostasis (water reabsorption in collecting duct)
VASOPRESSIN /ADH/Arginine vasopressin
urine output in increased ADH? example?
decreased urine output
SIADH
urine output in decreased ADH? example?
increased urine output
Diabetes insipidus
Stimulates FVII and vWF
VASOPRESSIN /ADH/Arginine vasopressin
Synthesized by magnicellular neurons of supraoptic
VASOPRESSIN /ADH/Arginine vasopressin
Reference value of ADH
0.5-2 pg/uL
2 types of Diabetes Insipidus
Nephrogenic DI
Neurogenic DI / True DI / Hypothalamic DI / Central DI / Cranial DI
Polyuria (due to kidney resistance to ADH; no
receptors), normal ADH, and milder symptoms
Nephrogenic DI
Polyuria, ↓ ADH
Neurogenic DI / True DI / Hypothalamic DI / Central DI / Cranial DI
Same symptoms for 2 Types of DI
- ADH deficiency (except nephrogenic)
- Severe polyuria (↑ urine output; hyperosmotic blood)
- Polydipsia (↑ thirst promotion)
- Occasional polyphagia
Hyperosmosis promotes:
ADH secretion
Thirst
TEST for DI
Overnight Water Deprivation Test
Definitive test for Diabetes Insipidus
Overnight Water Deprivation Test
Px Preparation in overnight water deprivation test? what will be the effect in ADH?
8-12 hrs fasting w/o water intake
o normal: hyperosmolality, promotes ↑ ADH
o DI: hyperosmolality, still ↓ ADH
Overnight Water Deprivation Test value for diabetes insipidus
≤300 mOsm/kg
aka PINEAL GLAND
CONARIUM/EPIPHYSIS CEREBRI
Pineal gland is attached to this structure
midbrain
Function of pineal gland
secretes melatonin
Melatonin is for
a) Sleep cycle
b) ↓ skin pigmentation
control the secretion of melatonin produced by pineal gland
nerve stimuli
melatonin secretion is stimulated and inhibited during
stimulated: darkness (Circadian rhythm at night)
Inhibited: light (daytime or ↑ screen time)
Pituitary gland is called as master gland due to this reason
It controls other glands
releasing hormone produced by hypothalamus will act directly on?
pituitary gland
markedly increased GH level is seen during
deep sleep
end product of anabolic and catabolic processes
energy
T/F
Manifestation of Prolactinoma depends on age group and onset of menopause
T
amino acid can stimulate/decrease GH secretion? what is the example?
stimulate
Ex: arginine
sex steroids can stimulate/inhibit GH secretion? what is the example?
stimulate
Ex: estradiol
a-agonist can stimulate/inhibit GH secretion? what is the example?
stimulate
Ex: norepinephrine
b-blockers can stimulate/inhibit GH secretion? what is the example?
stimulate
Ex: propanolol
b-agonist can stimulate/inhibit GH secretion? what is the example?
inhibit
Ex: epinephrine
a-blockers can stimulate/inhibit GH secretion? what is the example?
inhibit
Ex: phentolamine
GH secretion during:
physiologic stress?
emotional/psychogenic stress?
physiologic stress: stimulates GH
emotional/psychogenic stress: inhibits GH
highest conc of ACTH is seen during
6-8am
lowest conc of ACTH is seen during
6-11pm
corresponding amino acid of leucine in structure of oxytocin to vasopressin
arginine
corresponding amino acid of isoleucine in structure of oxytocin to vasopressin
phenylalanine
synthetic ADH for treatment
desmopressin
receptor of ADH responsible for water permeability? what is the channel?
V2 receptors
aquaporin-2
receptor of ADH responsible for vasoconstriction
V1 receptor
immediate detectable lost hormones
tropic hormones (ACTH, TSH, LH, FSH)
Delayed unnoticeable lost hormones
direct effectors (GH and prolactin)
It is where 80-90% of the blood supply and hypothalamic factors pass and received by anterior pituitary gland
hypothalamic–hypophyseal portal system
Level of prolactin that can cause anovulation
> 200 ng/ml