Exam 2: Endo Intro Flashcards
What are trophies hormone effects?
It regulates hormone secretion by another gland and the growth and integrity of the endocrine gland
What is a paracrine hormone?
A hormone that regulates processes in neighboring cells
What is an autocrine hormone?
A hormone that acts back on the cell it was released from to regulate processes within that cell
What is an intracrine hormone?
A hormone that regulates processes within the cells without being secreted
What are neurocrine hormones?
Hormones that originate in the neuron and after axonal transport, is carried distally either by a blood vessel or synaptic transmission
The majority of hormones are ***. These are derived from?
Peptide hormones.
Amino acids
Amino hormones are derived from ***.
Tyrosine
Hydrophobic proteins are transported bound to ***.
Binding proteins
Are peptide hormones and catecholamines hydrophilic or hydrophobic?
Hydrophilic
What membrane located enzyme, second messenger, and kinase do group IIA hormones use?
Membrane enzyme: Adenylyl cyclase
Second messenger: cAMP
Kinase: cAMP dependent protein kinase
What membrane located enzyme, second messenger, and kinase do group IIB hormones use?
Membrane enzyme: guanylyl cyclase
Second messenger: cGMP
Kinase: c-GMP dependent protein kinase
What membrane located enzyme, second messenger, and kinase do group IIC hormones use?
Membrane enzyme: Phospholipase C
Second messenger: DAG and IP3
Kinase: protein kinase C, camodulin depende protein kinase
Where are peptide hormones synthesized?
Ribosomes, ER, and golgi
Where are peptide hormones stored?
Granules
Where are amine hormones synthesized?
Enzymatically in cytosol (catecholamines)
Follicular cells and colloid of thyroid (T3 andT4)
Where are amine hormones stored?
In granules (Amines) and follicular cells (T3 and T4)
Where are steroid hormones synthesized?
Cytosol, ER, and mitochondria
What is the active version of vitamins 3? Where does this conversion happen?
1,25- dihydroxyvitamine D3
Hydroxylations occur in the liver and kidney
What is humoral hormone secretion?
Hormone release that is activated by blood born substrate
Ex)low plasma Calcium triggers PTH release from parathyroid gland
What is neural hormone secretion?
An extension of the CNS that signals a gland to secrete hormones
Ex) fight to flight response and altered physiologic states (Hypoglycemia, exercise, shock, and stress)
What is hormonal hormone secretion?
Hormones that regulate the secretion of other hormones.
Ex) hypothalamic factors (TRH) stimulates pituitary hormones (TSH) which stimulates the endocrine gland (thyroid) to secrete thyroid hormone
Hydrophilic hormones bind to receptors located on ***.
The outer cell membrane of the target cell
Hydrophobic hormones bind to ***.
A nuclear receptor within the cell, they must diffuse through the lipid bilayer
What is the threshold of hormone action?
The minimal amount of hormone needed to achieve an effect
What is tissue sensitivity to a hormone?
The hormone concentration that produces 50% of the maximal response.
Determines how sensitive or resistant tissues are to a hormone
What is the maximal dose of a hormone?
The effect of a saturating hormone dose. When adding more hormone wont change the response
What does it mean if a hormone is permissive?
It cannot exert its full effects without another hormone being present.
What are the 4 glycoproteins that are also in the peptide hormone family?
FSH, TSH, LH, and hCG
What are the 3 functions of binding proteins?
1) provides a reserve that can be called upon to replenish the free pool
2) Keeps the hormone in the blood in the inactive state
3) involved in hormone turnover, which is the rate at which the hormone is released into the plasma and removed from the plasma.
How go group 1 hormones do signal transduction?
They enter the cell nucleus where they bind to receptors on the DNA where specific thyroid (TSE) or steroid responsive elements (SRE) are activated
