Intro to Endocrinology Flashcards
What is juxtacrine signaling?
Physical interaction between cells. Examples are RANK-RANKL and FAS-FASL.
What is intacrine signaling?
When a molecule released by one part of the cell interacts with another part of the cell. Example is IP3
What does dopamine do primarily?
Inhibits prolactin release from the AP
A pituitary tumor that releases GH (sommatotroph tumor) will cause ________ if growth plates haven’t closed yet, and ________ if the growth plates have already closed.
gigantism if the growth plates have not closed
acromegaly if the growth plates have already closed
How does GH affect glucose tolerance?
Excess GH causes insulin insensitivity.
Explain how GH affects body fat homeostasis.
GH binds directly to adipose cells –> lipolysis.
Explain how GH affects stature.
It binds to receptors on liver cells –> IGF-1.
Name three polypeptide hormones.
- Insulin
- Glucagon
- PTH
Name three steroid hormones.
- Cortisol
- Estradiol
- Cholecalciferol
Name three AA derivative hormones.
- Epinephrine
- Norepinephrine
- T3
Name two lipid hormones.
- Prostaglandins
2. Leukotrienes
Name a gas hormone.
Nitric oxide
What hormone has a very long half life?
Thyroxine (7 days)
What hormones have very short half lives?
Epi and norepi (15 seconds)
Peptide hornomes are stored in…?
secretory vesicles
Are steroid hormones not stored, but synthesized from stored cholesterol?
Yeah
How is hormone association equilibrium calculated?
[HR]/[H][R] = K1/K2 = Kassociation
Where are T3’s cellular receptors located (intracellular or extracellular)?
intracellular - in the nucleus!
By what receptor mechanism does epi and norepi illicit a cellular response?
Extracellular receptor binding –> signal transduction –> cAMP, Ca, cGMP, PIP3, DG –> phosphorylation
The insulin receptor beta subunit has ______ _______ activity. Is this receptor in the plasma membrane?
tryosine kinase
yeah its in the plasma membrane
Aminoglutethimide is a drug that blocks the conversion of cholesterol to pregnenolone. Administration of this drug would decrease the circulating levels of:
a) insulin
b) epinephrine
c) T3
d) cortisol
d) cortisol
A hormone that acts by binding to receptors that are primarily in the nucleus is:
a) insulin
b) T3
c) glucagon
d) epinephrine
e) ACTH
b) T3
The effects of GH on stature are mediated by:
a) t3
b) insulin
c) somatostatin
d) IGF-1
e) glucocorticoid
d) IGF-1
Which of the following hormones have receptors that are integral tryosine kinases?
a) glucocorticoid
b) prolactin
c) GH
d) PTH
e) insulin
e) insulin
