What endocrine methods are used for local hormone rxns?
autocrine and paracrine
What endocrine methods are used for distant rxns?
Endocrine and Neurocrine
What is necessary to begin peptide hormone release?
cAMP and Ca2+
What activates the amine synthetic pathway in the adrenal medullae?
What activates the amine pathway in the thyroid gland?
T/F: Steroid hormones are not stored after synthesis?
What are the three methods of hormone secretion?
- 1) humoral
- 2) neuronal
- 3) hormonal
What is humoral secretion of hormones?
- When the blood concentration of a specific hormone product either increases or decreases
- The hormone will then do the inverse to counteract the imbalance
What is an example of humoral hormone secretion?
Low Ca causes more PTH to be produced
What is an example of neuronal hormone secretion?
fright - SNS firing - Adrenal medulla release of catecholamines
What is an example of hormonal hormone secretion?
- CRH from hypo
- ACTH from Pituitary gland
- Cortisol from Adrenal gland
What is the difference b/t where a hydrophilic and hydrophobic hormone bind?
- hydrophilic = cell membrane receptor
- hydrophobic = nuclear membrane receptor
What are thre common effectors of G protein receptors?
- Guanylate cyclase - cGMP
- Adenylyl cyclase - cAMP
- PLC - IP3+/Ca2+
What is the nuclear binding receptor for steroid hormones called?
What are the areas of the SRE receptor and what binds to the areas?
- A/B, C, D, E, F
- Hormone binds E
- DNA binds C at zinc fingers
Which is more common, negative or positive feedback?
What are three hormones that are regulated with positive feedback
- 1) oxytocin
- 2) Na deplorization
- 3) Estrogen
What is the diff b/t autologous and heterologous receptor regulation?
- Autologous: regulates own receptors
- Heterologous: regulates another cell's receptors
What is hormonal synergism?
Sum of parts is greater than each part itself
What is hormonal permisiveness?
One hormone affects how another hormone reacts, but it does not add to its affect
What is hormonal antagonism?
Hormone A reduces effects of Hormone B
What are the three classes of endocrine disorders?
- 1) underproduction
- 2) overproduction
- 3) sensitivity
What is the diff in the way that hormones are released from the Ant/Post pituitary?
- Ant.: Neurocrine (inside) then Endocrine (exit)
- Post.: Neurocrine
Where are the Ant/Post pituitary derived from?
- Ant: Gut
- Post: brain, neural tissue
What four Ant. Pit. Hormones stimulate gland growth and hormone secretion?
ACTH, TSH, FSH, LH
What two Ant. Pit. Hormones stimulate non-endocrine tissue?
What is the function of TSH?
- Release thyroid from thyroid gland
- growth of thyroid gland
What is the function of ACTH?
- Activate adrenal gland
- Release androgen and cortisol
What is the function of FSH in M/F?
- females: follicular dev. for egg locations
- males: sperm production
What is the function of LH in M/F?
- females: ovulation, secretion of estrogen and progesterone
- Males: testosterone secretion
What is the function of GH?
Growth and metabolism
What is the function of PRL in M/F?
- females: Increase milk production
- males: LH receptors
What binds ADH and Oxytocin in the axons leading to the Posterior Pituitary?
What is the combination molecules makeup that carries ADH (AVP) down the axon in the posterior pituitary?
- 4 Neurophysins (NP)
- 5 ADH (AVP)
What is the function of ADH?
- Water retention
- Plasma volume restoration
- decrease plasma osmolarity
As blood volume is increased, what happens to ADH?
What are the two principle functions of oxytocin?
- Milk letdown
- uterine contractions
What is the role of Oxytocin and ANP?
Oxytocin increases ANP release (since we want to lower blood pressure)
What is the key sign of diabetes insipidus and the cause?
- sign: dilute urine
- Cause: lack of ADH (neurogenic or nephrogenic)
What is the diff b/t hypopituitarism and panhypopituitarism?
- Hypo: loss of one or more anterior pituitary hormone (ACTH, LH, FSH, LSH, GH, PRL)
- Pan: Loss of all anterior pituitary hormone
What does GH bind too?
GH-binding protein *
*not necessary b/c it is a hydrophilic peptide but since it is so important and critical it is nice to increase the half life
When is GH release more prevalant, day or sleep (be specific)?
Sleep, especially at the beginning
T/F GH levels are higher in adults than children?
- * Higher in children than adults
What hormones inhibit secretion of GH?
- Somatomedins (somatostatin, IGF)
- GHRH (short loop)
- GH (Long loop)
What is required for GH to be Ketogenic?
T/F GH is lipolytic?
T, active when FFA are low to isolate fat
Is protein anabolic or catabolic?
- * helps build muscle
What is the effect of GH on insulin?
GH causes insulin resistance b/c it inhibits glucose uptake by insulin
What is the effect of GH on ANP and Renin?
- ANP decreases
- Renin increases
- ** increase ECF volume
Increases IGF-BP1 production
glucagon and cortisol
Inhibits IGF-BP1 production
What type of growth does IGF-1 increase?
Linear bone growth
T/F GH increases in the fed and fasting state?
T/F GH increases in Carbohydrate fed state?
- * Occurs b/c of high glucose level on carbs and the increase in insulin. That will inhbit GH and IGF-1
What happens with GH if there is too much carb intake?
Increases to block effects of insulin and can cause type II diabetes
What is the diff b/t acromegaly and gigantism?
- acromegaly: GH increased after puberty
- gigantism: GH increased before puberty
What are the five main functions of the thyroid gland?
- Heat production
- energy mobilization
In thyroid cells, what cells produce Calcitonin?
Parafollicular (P or C) cells
What happens to colloid in times of hypo/hyperthyroidism?
- Hypo: colloid not absorbed
- Hyper: colloid absorbed, removed
What are the four steps of thyroid production?
- 1) Iodide uptake: from food via Na channel (uptake tyrosine from blood as well)
- 2) Incorporation: bring iodide and tyrosine together (via oxidation and organification)
- 3) Coupling: Bring tyrosines together to form Thyroid
- 4) Diffusion: Release thyroid finto blood
What hormone increase Iodide receptors for uptake into Thyroid glands?
What is the function of Pendrin in the thyroid gland?
- ** Oxidation **
- Pendrin moves Iodide to the apical membrane once inside the thyroid gland
What is the function of Thyroglobulin?
- ** organification **Once Iodide is at the apical membrane, it is incorporated with Tyrosine
What is the function of the Wolff-Chaikoff Effect?
- Inhibit the amount of Iodine incorporation by mainly blocking Na/I channels
- Allows thyriod to settle to normal levels
What is the function of Thyroid peroxidase?
Couple Tyrosines (Mono and Di) to form T4 and T3
What is the function of Megalin?
To activate Colloid endocytosis into follicular cells so T4 and T3 can be released in the blood
What chemical activates the splitting of T3, T4, MIT, and DIT fro Thyroglobulin?
What Thyroid Deiodinase will make T3 from T4?
What are the negative feedback mechanisms of Thyroid production?
- T3 (and some T4)
What organs do not receive calorgenis effects from thyroid hormone?
Why is Thyroid hormone important in the fetus?
What happens to TSH levels when Thyroid hormone is low?
- TSH increases
- **Occurs b/c of lack of negative feedback from T3
What is the function of Levothyroxin sodium?
What is the function of Methylthiouracil?
- decrease coupling
- decrease oxidation
- decrease Na/I pump uptake
What is the function of Propylthiouracil?
- decrease coupling
- decrease oxidation
- decrease T4-T3 conversion via Thyroid deiodinase
When are cortisol levels the highest?
Early AM (start to increase during sleep)
Other than insulin resistance and gluconeogenesis, what are five other functions of Cortisol?
- maintain BP: Alpha-1 receptor
- Anti-inflammation: Block IL-2
- Antagonize Vit. D function: Inhibit Calcium reabsorption, demineralize b one
- CNS: emotion, decrease REM, more awake
- Fetal dev.: surfactant, GI tract
What state are the ECF and K in to activate Aldosterone?
What is the primary sign of Addison's disease?
All three zones of cortex not producing (no cortisol, no aldosterone, no androgens)
What is the diff b/t Cushing's syndrome and disease?
- Syndrome: ACTH low, Cortisol high
- Disease: ACTH high
How does the Dex suppression test function?
- Dex is an artificial Cortisol
- In Cushing's syndrome, there is not ACTH to inhibit so Cortisol levels stay the same
- In Cushing's disease, there is high ACTH so dex acts like extra Cortisol and will inhibit Cortisol and ACTH production
What causes Cushing's Hypersecretion?
- ACTH secreting tumor some where else in body
- No treatment can decrease Cortisol or ACTH production
What causes Conn's syndrome?
Aldosterone secreting tumor
How do you treat Conn's syndrome?
- Spironolactone to inhibit Aldo
- Remove tumor
What is Androgenital syndrome?
Too much androgen (DEHA and Androstenedione)
What does Monoamine oxidase (MAO) inhibit?
What does COMT inhibit?
What is Pheochromocytoma?
Overproducing adrenal medulla causing abundance of Catecholamines
What is the hormone of abundance and starvation?
- abundance: insulin
- starvation: glucagon (secreted with cortisol)
What do the Beta, Alpha and Delta cells of Langerhan cells produce?
- Beta = insulin
- Alpha = Glucagon
- Delta = Somatostatin
What is measured to indicate insulin levels?
C-Protein (b/c of long half life and short half-life of insulin)
What is the normal ratio of Insulin:Glucagon?