EXAM 5 Module 9 Flashcards
when hormones are secreted directly from gland cells through the interstitial and into the bloodstream
endocrine secretion
when a variety of substances (ex. sweat, sebum, enzymes, mucus) are secreted through ducts onto body surfaces or in organ lumens
exocrine secretion
amine hormone precursor with HO, CH2, NH2, C, H, and COOH
tyrosine
2 classes of amine hormones
thyroid hormones
catecholamines
ex. of thyroid hormones
T3 and T4
ex. of catecholamines
norepinephrine
epinephrine
dopamine
ex. of a peptide hormone
insulin
_______ hormones are synthesized from cholesterol
steroid
_______ (hydrophilic) hormones such as catecholamines and peptides/proteins bind to ________________ and can trigger a variety of effects
water-soluble;
cell surface receptors
free _________ (hydrophobic) hormones such as steroid hormones are carried through plasma on ___________
lipid-soluble;
transport proteins
hormones diffuse away from transport proteins and across ___________
plasma membranes
lipid-soluble hormones bind _____________ and these complexes bind DNA to affect ___________ in the nucleus
intracellular receptors;
gene expression
3 inputs that control hormone secretion
ions or nutrients
neurotransmitters
hormones
ex. of regulatory ions or nutrients
insulin secretion from the pancreas is regulated by plasma glucose levels
ex. of regulatory neurotransmitters
epinephrine secretion from the adrenal medulla is under neural control
ex. of regulatory hormones
cortisol secretion from the adrenal cortex is stimulated by a pituitary hormone
possible fates of hormones after circulating in the blood
can be excreted in urine or feces
can be inactivated by metabolism
can be activated by metabolism
can reach target cells
ex. that goes through multiple steps of activation by metabolism
vitamin D
when hormones reach target cells, they bind to a _______ and produce a ___________
receptor;
cellular response
hormone A must be present for hormone B to have its full effect
permissiveness
little or no fatty acids released
thyroid hormone
small amount of fatty acids released
epinephrine
large amount of fatty acids released
epinephrine + thyroid hormone
integrates inputs from the body for many metabolic functions and releases hormones
hypothalamus
releases hormones in response to hypothalamic signals
pituitary
2 lobes of pituitary
anterior (adenohypophysis)
posterior (neurohypophysis)
receives hormones from the hypothalamus through portal vessels
anterior lobe
neural extension of the hypothalamus
posterior lobe
hormones released from anterior pituitary
FSH/LH
ACTH
TSH
prolactin
GH
hormones released from posterior pituitary
ADH/vasopressin
oxytocin
hypothalamic hormones that trigger the anterior pituitary
GnRH
CRH
TRH
dopamine
GHRH
somatostatin
hormones that act on other endocrine glands to influence the secretion of the glands’ hormones
tropic hormones
ex. of tropic hormones
hypophysiotropic
gonadotropins
somatrotropin
thyrotropin
tropic hormone from the hypothalamus that act on the hypophysis (pituitary)
hypophysiotropic
tropic hormone that acts upon the gonads
gonadotropin
tropic hormone that acts upon the body (growth hormone)
somatrotropin
tropic hormone that acts upon the thyroid (TSH)
thyrotropin
when the pituitary gland sends feedback to the hypothalamus to control how much hormone the hypothalamus releases
short-loop feedback
when the final hormone sends a message back to both the pituitary and hypothalamus to reduce hormone production
long-loop feedback
HPX stands for…
hypothalamus-pituitary + 3rd endocrine gland
a condition in which an endocrine gland makes too little hormone
hyposecretion
a condition in which an endocrine gland makes too much hormone
hypersecretion
dysfunction of the endocrine gland
most common
primary disturbance
dysfunction of the pituitary
secondary disturbance
dysfunction of the hypothalamus
tertiary disturbance
2 forms thyroid hormone is made in
thyroxine (T4)
triiodothyronine (T3)
thyroid hormones are iodinated, and the numbered names refer to the number of _______ attached
ion atoms
although T4 is more abundant and stable than T3, it is considered to be essentially ________
inactive
the major thyroid hormone
T3
the stable reservoir for production of T3 (ex. a prohormone)
T4
iodide enters the ______ through anion transporters of follicle cells
colloid
iodide is attached to ___________ of thyroglobulin to make MIT or DIT
tyrosine residues
MIT and DIT are cleaved and attached to other DITs to make __________
thyroid hormone
when TH is needed, thyroglobulin is ________ and cleaved
endocytosed
TRH stands for…
thyrotropin-releasing hormone
TSH stands for…
thyroid-stimulating hormone
TH stands for…
thyroid hormone
thyroid hormone creates ___________ feedback on both TRH production by the hypothalamus and TSH production by the anterior pituitary
long-loop negative
thyroid hormone effects:
_________ metabolism
_________ for catecholamine effects
required for ______________
increased;
permissive;
normal growth and development
common causes of hypothyroidism
iodine deficiency
autoimmune thyroiditis
condition where the thyroid hormone synthesis is compromised
most common worldwide
iodine deficiency
condition of autoimmune destruction of thyroid gland
most common in U.S.
ex. Hashimoto’s Disease
autoimmune thyroiditis
hypothyroidism present at birth
congenital hypothyroidism
blood tests in hypothyroidism
low TH (T4) and high TSH
may occur due to high TSH levels in hypothyroidism
goiter
most common hyperthyroidism
Grave’s Disease (autoimmune disorder)
blood tests in hyperthyroidism
high TH (T4), low TSH. and presence of autoimmune antibodies
may be present in hyperthyroidism
goiter and thyroid eye disease
