Intro Flashcards
How do sympathetic NS and endocrine system respond to hypoglycemia?
SNS - releases epi, breaking down glycogen
Endocrine:
1. Pituitary releases ACTH, which tells adrenal gland to release cortisol, which facilitates glycogenolysis and gluconeogenesis
2. Glucagon released from alpha cells
3. GH released from pituitary
How do sympathetic NS and endocrine system respond to blood volume loss?
SNS - releases epinephrine for vasoconstriction
Endocrine:
1. Pituitary releases ACTH which releases cortisol from adrenal gland which reabsorbs salt and thus water in kidneys
2. Aldosterone released from adrenal cortex
3. ADH released from posterior pituitary
Name similarities between hormones and neurotransmitters.
- Secrete into blood
- Regulation by electrical potentials
- Bifunctional molecules like dopamine and epinephrine
- Co-transcription/translation/secretion
How do glycoprotein hormones differ from each other?
All have identical alpha subunit, but different beta subunits.
What modification is performed to make steroid hormones?
Hydroxylations on cholesterol
What is stored in granules with the hormone until it is ready for release?
Hormone copeptides
What is the pathway of synthesis for a hormone?
Preprohormone (w/ signal peptide) => Prohormone => Hormone
What are the three types of regulation of hormone secretion?
- Neural (adrenergic, cholinergic, dopaminergic, etc)
- Chronotropic (oscillating, pulsatile, diurnal, menstrual, seasonal, etc.)
- Feedback - pathway products inhibit release of more hormone
What determines the half-life of the hormone?
Protein binding - the more protein binding, the longer the half life
What types of receptor systems contribute to graded response of hormonal interactions?
G-protein coupling, peptide and catecholamine receptors, second messengers
How do steroid hormones work? Is the response fast or slow?
Go through membrane, activate transcription of certain genes in nucleus - response is delayed and prolonged
What three parts do nuclear receptors classically have?
- Binds to DNA
- Binds to hormone
- Binds to another factor like TF, peptide, etc.