NU 545 Unit 3 EXAM QUESTIONS WITH
CORRECT ANSWERS 2026
know which hormones are water-soluble and which are lipid-soluble - CORRECT ANSWER -water
soluble:
peptides- GH, insulin, leptin, PTH, prolactin
glycoproteins- FSH, LH, TSH
polypeptides: adrenocorticotropic hormone, ADH, calcitonin, endorphins, glucagon,
hypothalamic hormones, lipotropins, melanocyte-stimulating hormone, oxytocin, somatostatin,
thymosin, thyrotropin-releasing hormone
amines: Epi, Norepi
lipid soluble:
Thyroxine: T3 and T4
steroids: Estrogen, glucocorticoids, mineralocorticoids, progestin, testosterone (all steroids are
cholesterol based)
derivatives of arachidonic acid (autocrine or paracrine action):
Leukotrienes, Prostacyclins, prostaglandins, thromboxanes
How are water-soluble hormones transported? - CORRECT ANSWER -Water-soluble hormones
are proteins that are polarized with a high molecular weight. Because they cannot diffuse across
the lipid cell plasma membrane, they must interact or bind with receptors in or on the cell
membrane to activate a second-messenger to mediate short-acting responses.
,How are lipid-soluble hormones transported? - CORRECT ANSWER -Lipid-soluble hormones
diffuse freely across the cell and nuclear membrane and bind with cytosolic or nuclear
receptors. (can also bind with receptors in or on the plasma membrane)
know how protein hormones are transported in the blood - CORRECT ANSWER -peptide or
protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life? - CORRECT ANSWER -because they are
catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood? - CORRECT ANSWER -For hours to
days. They last longer in the blood because they are bound to carrier/transport proteins.
only free hormones can do what? - CORRECT ANSWER -initiate changes within a target cell
How does the concentration of binding proteins affect the concentration of free hormones in
the plasma? - CORRECT ANSWER -because equilibrium exists between the concentration of free
hormones and hormones bound to plasma proteins
What are the two main functions of the target cell hormone receptor? - CORRECT ANSWER -1.
To recognize and bind with high affinity to their particular hormones
2. To initiate a signal to appropriate intracellular effectors
*when a hormone is released into the circulatory system, it is distributed throughout the body,
but only those cells with appropriate hormone receptors for that hormone are affected.
what is oxytocin? - CORRECT ANSWER -a polypeptide hormone synthesized in the supraoptic
and paraventricular nuclei of the hypothalamus. Oxytocin is implicated in behavior responses,
, especially in women. Oxytocin plays a role in brain responsiveness to stressful stimuli, especially
in the pregnant and postpartum states.
How does oxytocin relate to the pituitary gland? - CORRECT ANSWER -the posterior pituitary
stores and secretes oxytocin.
Once synthesized, oxytocin is packaged in secretory vesicles along with its neurophysin and
moved down the axons of the pituitary stalk to the pars nervosa for storage.
Release of oxytocin is mediated by what? - CORRECT ANSWER -cholinergic and adrenergic
neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects? - CORRECT ANSWER -it is secreted from the
posterior pituitary. Oxytocin is responsible for the contraction of the uterus and milk ejection in
lactating women and may affect sperm motility in men. Oxytocin is released in response to
suckling (oxytocin binds to receptors on myoepithelial cells in the mammary tissue and cause
contraction causing milk expression or let down reflex) and distention of the uterus (oxytocin
stimulates contractions with a positive feedback loop).
Where is ADH secreted? - CORRECT ANSWER -ADH is produced in the hypothalmus and
secreted by the posterior pituitary. ADH and the posterior pituitary regulate osmolality.
Where does ADH act? - CORRECT ANSWER -ADH acts on vasopressin (V2) receptors of the renal
tubular cells to increase their permeability, which leads to increased water absorption in the
blood stream, increasing the concentration of urine and reducing serum osmolality.
what causes ADH to be secreted? - CORRECT ANSWER -when plasma osmolality increases, the
osmoreceptors of the hypothalamus are stimulated- the rate of ADH secretion is increased
causing more water to be absorbed by the kidneys- the plasma osmolality returns to its set
point (280 mOsm/kg)
CORRECT ANSWERS 2026
know which hormones are water-soluble and which are lipid-soluble - CORRECT ANSWER -water
soluble:
peptides- GH, insulin, leptin, PTH, prolactin
glycoproteins- FSH, LH, TSH
polypeptides: adrenocorticotropic hormone, ADH, calcitonin, endorphins, glucagon,
hypothalamic hormones, lipotropins, melanocyte-stimulating hormone, oxytocin, somatostatin,
thymosin, thyrotropin-releasing hormone
amines: Epi, Norepi
lipid soluble:
Thyroxine: T3 and T4
steroids: Estrogen, glucocorticoids, mineralocorticoids, progestin, testosterone (all steroids are
cholesterol based)
derivatives of arachidonic acid (autocrine or paracrine action):
Leukotrienes, Prostacyclins, prostaglandins, thromboxanes
How are water-soluble hormones transported? - CORRECT ANSWER -Water-soluble hormones
are proteins that are polarized with a high molecular weight. Because they cannot diffuse across
the lipid cell plasma membrane, they must interact or bind with receptors in or on the cell
membrane to activate a second-messenger to mediate short-acting responses.
,How are lipid-soluble hormones transported? - CORRECT ANSWER -Lipid-soluble hormones
diffuse freely across the cell and nuclear membrane and bind with cytosolic or nuclear
receptors. (can also bind with receptors in or on the plasma membrane)
know how protein hormones are transported in the blood - CORRECT ANSWER -peptide or
protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life? - CORRECT ANSWER -because they are
catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood? - CORRECT ANSWER -For hours to
days. They last longer in the blood because they are bound to carrier/transport proteins.
only free hormones can do what? - CORRECT ANSWER -initiate changes within a target cell
How does the concentration of binding proteins affect the concentration of free hormones in
the plasma? - CORRECT ANSWER -because equilibrium exists between the concentration of free
hormones and hormones bound to plasma proteins
What are the two main functions of the target cell hormone receptor? - CORRECT ANSWER -1.
To recognize and bind with high affinity to their particular hormones
2. To initiate a signal to appropriate intracellular effectors
*when a hormone is released into the circulatory system, it is distributed throughout the body,
but only those cells with appropriate hormone receptors for that hormone are affected.
what is oxytocin? - CORRECT ANSWER -a polypeptide hormone synthesized in the supraoptic
and paraventricular nuclei of the hypothalamus. Oxytocin is implicated in behavior responses,
, especially in women. Oxytocin plays a role in brain responsiveness to stressful stimuli, especially
in the pregnant and postpartum states.
How does oxytocin relate to the pituitary gland? - CORRECT ANSWER -the posterior pituitary
stores and secretes oxytocin.
Once synthesized, oxytocin is packaged in secretory vesicles along with its neurophysin and
moved down the axons of the pituitary stalk to the pars nervosa for storage.
Release of oxytocin is mediated by what? - CORRECT ANSWER -cholinergic and adrenergic
neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects? - CORRECT ANSWER -it is secreted from the
posterior pituitary. Oxytocin is responsible for the contraction of the uterus and milk ejection in
lactating women and may affect sperm motility in men. Oxytocin is released in response to
suckling (oxytocin binds to receptors on myoepithelial cells in the mammary tissue and cause
contraction causing milk expression or let down reflex) and distention of the uterus (oxytocin
stimulates contractions with a positive feedback loop).
Where is ADH secreted? - CORRECT ANSWER -ADH is produced in the hypothalmus and
secreted by the posterior pituitary. ADH and the posterior pituitary regulate osmolality.
Where does ADH act? - CORRECT ANSWER -ADH acts on vasopressin (V2) receptors of the renal
tubular cells to increase their permeability, which leads to increased water absorption in the
blood stream, increasing the concentration of urine and reducing serum osmolality.
what causes ADH to be secreted? - CORRECT ANSWER -when plasma osmolality increases, the
osmoreceptors of the hypothalamus are stimulated- the rate of ADH secretion is increased
causing more water to be absorbed by the kidneys- the plasma osmolality returns to its set
point (280 mOsm/kg)
