Intro To Endocrinology Flashcards
Define hormone
a chemical substance that sends a message to another cell in the body.
Describe amine classification of hormones
Tryptophan or tyrosine (amino acids) are modified to create amine hormones
- Very short half lives
Describe peptide classification of hormones
- Is generally considered to be an unbroken chain of amino acids of 50 or less
- binds membrane bound receptors
- Vasopressin and oxytocin
Describe glycoprotein classification of hormones
- Are conjugated proteins bound to carbohydrates (galactose, mannose, or fructose)
- FSH, LH, TSH
Describe steroid classification of hormones
- All derived from a lipid, typically cholesterol
- Hydrophobic; must be transported by carrier proteins
- can cross cell membranes because of lipid content
List examples of steroid hormones
Aldosterone, cortisol, estrogens, progesterone, testosterone, other androgens (DHEA)
Describe hormones formed from cholesterol and enzyme (1) necessary for formation
- aldosterone
- estrogen
- cortisol
- 21 hydroxylase is necessary
Describe how steroid hormones are eliminated
inactivating metabolic pathways and excretion in urine or bile
Describe how thyroid hormones are inactivated
intracellular deiodinases
Describe how catecholamines are eliminated
rapidly degraded within the blood circulation
What defines a primary endocrine disorder (general)
Final gland is misregulated
What defines a tertiary endocrine gland disorder (general)
The original organ (hypothalamus) is malfunctioning
List common hormones that are affected by psychological or emotional stress
glucocorticoids, catecholamines, growth hormone, and prolactin
List factors that can impact hormone levels
- emotional stress
- time of day
- menstrual cycle
- menopause
- diet
- drugs
What is another name for the anterior pituitary gland
adenohypophysis
What is another name for the posterior pituitary gland
neurohypophysis
What is the role of the posterior pituitary gland
Storage and release of hypothalamus hormones (AVP and oxytocin)
True or false
All anterior pituitary hormones are secreted in a pulsatile fashion
True
True or False
The pulse frequency of the regulatory hypothalamic hormone, Gonadotropin-releasing hormone (GnRH) has major effects on LH secretion profiles
True
List hormones secreted by the anterior pituitary gland
- GH
- TSH
-ACTH - FSH
- LH
- PRL
List hormones release by the posterior pituitary gland
- ADH
- oxytocin
Describe pituitary hormone complexity in comparison to hypothalamus hormones
Anterior pituitary hormones are larger and more complex in comparison
Describe the action of TRH
Hypothalamus hormone stimulates release of prolactin and TSH
Describe the action of GnRH
hypothalamus hormone Stimulates release of FSH and LH
Describe the action of CRH
Hypothalamus hormone stimulates release of ACTH
Describe the action of GHRH
Hypothalamus hormone stimulating release of GH (growth hormone)
Describe the action of somatostatin
Hormone inhibits release of of GH and TSH
describe actions of GH
- amphibolic hormone
- allows for intracellular oxidation in fed and fasting state
- stimulates glucose formation and release to tissues
name the major growth factor induced by GH
IGF-1
define acromegaly
excess production of GH (pituitary hyperproduction)
describe how GH excess differs in presentation when long bones are closed vs open
- before closure (growth spurts) results in gigantism
- after closure (post puberty) bony and soft tissue overgrowth
describe prolactin generally
- stress hormone
- reproduction functionality
- tonic inhibition NOT intermittent stimulation
- dopamine is a inhibitor factor
describe prolactinoma
- pituitary tumor that directly secretes prolactin
define hypopituitarism
failur eof pituitary of hypothalamus resulting in loss of anterior pituitary function
describe the synthesis of AVP and oxytocin
linked to production of neurophysin in hypothalamus as well as various tissues
describe oxytocin
- positive feedback loop for contractions
describe AVP
regulates renal free water excretion and promotes clotting and Von WIllebrand release