NU 545 UNIT 3 WITH 130 QUESTIONS & CORRECT
ANSWERS
know which hormones are water-soluble and which are lipid-soluble - 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? - 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? - 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 - ANSWER-peptide or
protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life? - ANSWER-because they
are catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood? - 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? - ANSWER-initiate changes within a target cell
How does the concentration of binding proteins affect the concentration of free
hormones in the plasma? - 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? - 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? - 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? - 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? - ANSWER-cholinergic and adrenergic
neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects? - 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? - ANSWER-ADH is produced in the hypothalmus and
secreted by the posterior pituitary. ADH and the posterior pituitary regulate
osmolality.
, Where does ADH act? - 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? - 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)
How does ADH effect electrolytes? - ANSWER-ADH does not directly effect
electrolytes but due to the dilutional effect of increasing water absorption, serum
electrolytes may decrease
How does the body detect volume loss in order to stimulate receptors to release
ADH? - ANSWER-Baroreceptors in the L Atrium, carotid arteries, and aortic arch
detect changes in intravascular volume. Once a volume loss of 7-25% is detected,
receptors are stimulated.
What can cause secretion of ADH? - ANSWER-stress, trauma, pain, exercise,
nausea, nicotine, exposure to heat, and drugs (morphine)
when does ADH secretion decrease? - ANSWER-when plasma osmolality
decreases/returns to normal, intravascular volume increases, with HTN, an increase
in estrogen, progesterone, angiotensin II, and alcohol ingestion.
How does ADH affect blood pressure? - ANSWER-ADH acts on vasopressin (V1)
receptors which cause vasoconstriction, - increasing blood pressure
ANSWERS
know which hormones are water-soluble and which are lipid-soluble - 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? - 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? - 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 - ANSWER-peptide or
protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life? - ANSWER-because they
are catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood? - 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? - ANSWER-initiate changes within a target cell
How does the concentration of binding proteins affect the concentration of free
hormones in the plasma? - 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? - 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? - 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? - 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? - ANSWER-cholinergic and adrenergic
neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects? - 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? - ANSWER-ADH is produced in the hypothalmus and
secreted by the posterior pituitary. ADH and the posterior pituitary regulate
osmolality.
, Where does ADH act? - 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? - 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)
How does ADH effect electrolytes? - ANSWER-ADH does not directly effect
electrolytes but due to the dilutional effect of increasing water absorption, serum
electrolytes may decrease
How does the body detect volume loss in order to stimulate receptors to release
ADH? - ANSWER-Baroreceptors in the L Atrium, carotid arteries, and aortic arch
detect changes in intravascular volume. Once a volume loss of 7-25% is detected,
receptors are stimulated.
What can cause secretion of ADH? - ANSWER-stress, trauma, pain, exercise,
nausea, nicotine, exposure to heat, and drugs (morphine)
when does ADH secretion decrease? - ANSWER-when plasma osmolality
decreases/returns to normal, intravascular volume increases, with HTN, an increase
in estrogen, progesterone, angiotensin II, and alcohol ingestion.
How does ADH affect blood pressure? - ANSWER-ADH acts on vasopressin (V1)
receptors which cause vasoconstriction, - increasing blood pressure
