Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
What does the hypothalamus secrete to anterior pituitary?
|
Hypophysiotrophic, ADH, oxytocin
|
|
|
What is secreted by anterior pituitary?
|
GF and ACTH
|
|
|
What are the 3 classes of hormones?
|
1. proteins (parathyroid/insulin) 2. steroids (cortisol/aldosterone) 3. derivatives of AA tyrosine (thyroid and adrenal medulla)
|
|
|
Epi and NorEpi are?
|
Derivatives of AA tyrosine (from adrenal-exocytosis)
|
|
|
When are prohormones cleaved?
|
In secretory vesicles by enzymes
|
|
|
What stimulates release of protein hormones?
|
Inc in Ca2+because of depolarization or cAMP: exocytosis
|
|
|
What are steroids made of?
|
3 cyclohexyl rings and 1 cyclopentyl ring
|
|
|
Where are thyroid hormones stored?
|
With protein thyroglobulin in Ig follicles
|
|
|
What carries thyroid hormones in the blood?
|
Thyroxine-binding globulin
|
|
|
What class is tyrosine derived hormones?
|
Amines
|
|
|
How are most hormones controlled?
|
Negative feedback (on secretion or target tissue activity)
|
|
|
What is an example of positive feedback?
|
In ovulation: LH increases estrogen then estrogen increases LH
|
|
|
How are proteins and catecholamines transported?
|
Dissolved in plasma
|
|
|
How do steroids and thyroid hormones travel?
|
Bound to plasma proteins
|
|
|
Rate of disappearance of hormone from plasma/concentration of hormone=
|
Metabolic clearance rate
|
|
|
How are hormones cleared?
|
1. metabolic destruction by tissues 2. binding 3. excretion by liver 4. excretion by kidneys
|
|
|
Where are steroid receptors?
|
Cytoplasm
|
|
|
Where are thyroid receptiors?
|
Nucleus
|
|
|
How are receptors down regulated?
|
1. Inactivation of some receptor molecules 2. Inactivation of intracellular protein signal molecules 3. Sequencing of receptors 4. destruction by lysosomes 5. decrease product of receptors
|
|
|
What do G-coupled protein receptors look like?
|
7 transmembrane segments
|
|
|
What does the inactive G complex look like?
|
Alpha, Beta, and Gamma subunits, with GDP bound to alpha
|
|
|
What causes activation of G complex?
|
Active receptor causes alpha to exchange GDP for GTP and alpha dissociates
|
|
|
What do enzyme linked hormone receptors look like?
|
1 transmembrane segment (with hormone binding extracellularly and enzyme binding intracellularly)
|
|
|
What is Leptin?
|
Cytokine
|
|
|
What signaling pathway does Leptin use?
|
Leptin binds to enzyme linked hormone receptor, phos JAK (tyrosine kinase which can also activate MAPK and PI3K), phos STAT, protein synthesis
|
|
|
What happens when a hormone binds a special transmembrane receptor?
|
becomes activated adenylyl cyclase intracellularly-> cAMP
|
|
|
Where do intracellular hormone-receptor complexes bind?
|
Regulatory sequence of DNA (hormone response element)
|
|
|
What is an example of a 2nd messenger?
|
cAMP, Ca2+/calmodulin
|
|
|
What does Gs do?
|
Stimulates adenylyl cyclase to catalyze cATP to cAMP
|
|
|
What does cAMP do?
|
Activates cAMP dependant protein kinase
|
|
|
What does Gi do?
|
Inhibit cAMP
|
|
|
The enzyme phospholipase C (attached intracellularly to receptor) causes what?
|
Phospholipid (PIP2) breakdown to DAG and IP3-> Ca2+
|
|
|
What does DAG do?
|
Activates PKC->Phosphorylation
|
|
|
What does Ca2+ activate?
|
Calmodulin
|
|
|
What does calmodulin do?
|
Activates/Inhibits proteins by stimulating/blocking kinases
|
|
|
What is aldosterone secreted by?
|
Adrenal cortex (Na+ reabsorbtion proteins and K+ secretion proteins)
|
|
|
What do thyroid hormones use as their receptor?
|
Activated TF in nucleus
|
