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Endocrine Physiology
Gilsonian Exam Flashcards- Endocrine
50
Physiology
Graduate
04/07/2012

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Term
Define Hormone
Definition
chemical substance that is classified as a peptide, steroid, or amine
Term
List all endocrine glands:
Definition
  • hypothalamus
  •  anterior and posterior pituitary
  •  thyroid
  •  parathyroid
  •  adrenal cortex
  • adrenal medulla
  • gonads
  •  placenta
  • pancreas
Term
Step 1 of peptide and protein hormone synthesis
Definition
  • in nucleus
  • gene from hormone is transcribed into mRNA
  • single gene is responsible for primary structure
Term
Step 2 of peptide and protein hormone sysnthesis
Definition
  • mRNA transferred to cytoplasm and translated on ribosomes
  • translated to preprohormone
  • translation begins with signal peptide on N terminus
  • translation ceases and attaches to receptors on ER
  • once attached translation continues until entire peptide is produced
Term
Step 3 of peptide and protein hormone sysnthesis
Definition
  • signal peptide is removed
  • preprohormone is converted to prohormone
  • prohormone contains complete hormone sequence plus other peptide sequences
Term
Step 4 of peptide and protein hormone synthesis
Definition
  • prohormone is transferred to golgi apparatus
  • prohormone is packaged into secretory vesicles
Term
Where are steroid hormones synthesized?
Definition
  • adrenal cortex
  • gonads
  • corpus luteum
  • placenta
Term
List of steroid hormones
Definition
  • cortisol
  • aldosterone
  • estradiol
  • estriol
  • progesterone
  • testosterone
  • 1,25-dihydroxycholecalciferol
Term
Are all steroid hormones derivatives of Cholesterol?
Definition
Yes
Term
List of amine hormones
Definition
  • epinephrine (catecholamine)
  • norepinephrine (catecholamine)
  • dopamine (catecholamine)
  • thyroid hormones
Term
What amino acid are amine hormones derivatives of?
Definition
Tyrosine
Term
How are secretory rates of hormones adjusted?
Definition
by neural mechanisms or by feedback mechanisms
Term
Example of Neural Mechanisms of Hormone Secretion: Secretion of Catecholamines
Definition
  • preganglionic sympathetic nerves synapse with adrenal medulla
  • when stimulated catecholamines are released into circulation
Term
Define Negative Feedback
Definition
some feature of hormone action, directly or indirectly, inhibits further secretion of the hormone
Term
Define Long-loop feedback
Definition
hormone feeds back all the way to the hypothalamic pituitary axis
Term
Define Short-loop Feedback
Definition
anterior pituitary hormone feeds back on the hypothalamus to inhibit secretion of hypothalamic-releasing hormone
Term
Define Ultrashort-loop Feedback
Definition

hypothalamic hormone inhibits its own secretion

ex. GHRH

Term
What is an example of negative feedback that doesn't utilize the hypothalamic-pituitary axis?
Definition
insulin and blood glucose concentrations
Term
What is a non-hormonal example of positive feedback?
Definition
opening of nerve sodium channels during the upstroke of an action potential
Term
What is the 1st hormonal example of positive feedback?
Definition
Estrogen on the secretion of FSH and LH
Term
What is the second hormonal example of positive feedback?
Definition
oxytocin and parturition
Term
Define Dose-response relationship
Definition
  • this is how the responsiveness of a target tissue to a hormone is expressed
  • the magnitude of response is correlated with hormone concentration
  • as hormone concentration increases so does the response and then it levels off
Term
Define Sensitivity
Definition
the hormone concentration that produces 50% of the maximal response
Term
What are the two ways to change the sensitivity of a target tissue?
Definition
  • by changing the number of receptors 
  • by changing the affinity of the receptors for the hormone
Term
Define Down-regulation
Definition
the number of receptors or the affinity of the receptors for the hormone has decreased
Term
Define Up-regulation
Definition
the number of the receptors or the affinity of the receptors has increased
Term
Thyrotrophs secrete:
Definition
TSH
Term
Gonadotrophs secrete:
Definition
FSH and LH
Term
Corticotrophs secrete:
Definition
ACTH
Term
Corticotrophs secrete:
Definition
ACTH
Term
Somatotrophs secrete:
Definition
GH
Term
Lactotrophs (mammotrophs) secrete:
Definition
PRL
Term
ACTH family includes:
Definition
  • ACTH
  • gamma-lipotropin
  • beta-lipotropin
  • beta-endorphin
  • melanocyte-stimulating hormone (MSH)
Term
preprohormone for the ACTH family:
Definition
prepro-opiomelanocortin
Term
anterior pituitary produces mainly:
Definition
  • ACTH
  • gamma-lipotropin
  • beta-endorphin
Term
Fragment left over after hydrolysis of POMC
Definition
gamma-MSH
Term
Fragment left over after hydrolysis of ACTH
Definition
alpha-MSH
Term
Fragment left over after hydrolysis of gamma-lipotropin
Definition
beta-MSH
Term
Addison's disease
Definition
  • primary adrenal insufficiency
  • POMC and ACTH increased by negative feedback
  • their MSH activity causes skin pigmentation which is a symptom of the disorder
Term
Which hormone is the single most important hormone for normal growth to adult stature?
Definition
Growth Hormone
Term
Growth Hormone has profound effects on:
Definition
  • protein metabolism
  • carbohydrate metabolism
  • fat metabolism
Term
Growth Hormone is also called:
Definition
somatotropin or somatotropic hormone
Term
How many amino acids are in Growth Hormone?
Definition
191 amino acids so the chemical class is protein
Term
What stimulates the synthesis of Growth Hormone?
Definition
GHRH
Term
how many amino acids does prolactin have?
Definition
198 amino acids so it is classified as a protein
Term
GHRH stimulatory pathway:
Definition
  • GHRH acts directly on somatotrophs
  • coupled through Gs protein to adenylyl cyclase and phospholipase C
  • utilizes both cAMP and IP3/Ca2+ as second messengers
Term
Somatostatin inhibitory pathway
Definition
  • also called somatotropin release-inhibiting hormone, SRIF
  • blocks action of GHRH
  • binds to its own membrane receptor
  • coupled to adenylyl cyclase by a Gi protein
  • inhibits generation of cAMP and decreases GH secretion
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