NU 545 Unit 3 Best Exam Questions
and 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
What is the target tissue and action of Thyrotropin-releasing hormone (TRH)? -
ANSWER-Anterior pituitary
Stimulates release of TSH and Modulates prolactin secretion
What is the target tissue and action of Gonadotropin-releasing hormone (GRH)? -
ANSWER-Anterior pituitary
Stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
What is the target tissue and action of Somatostatin? - ANSWER-Anterior pituitary
Inhibits release of growth hormone(GH) and TSH
What is the target tissue and action of Growth hormone-releasing hormone (GHRH)? -
ANSWER-Anterior pituitary
Stimulates release of GH
What is the target tissue and action of Corticotropin-releasing hormone (CRH)? -
ANSWER-Anterior pituitary
Stimulates release of adrenocorticotropic hormone (ACTH) and B-endorphin
What is the target tissue and action of Substance P? - ANSWER-Anterior pituitary
inhibits synthesis and release of ACTH
Stimulates secretion of GH, FSH, LH, and prolactin
What is the target tissue and action of Dopamine? - ANSWER-Anterior pituitary
Inhibits synthesis and secretion of prolactin
and 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
What is the target tissue and action of Thyrotropin-releasing hormone (TRH)? -
ANSWER-Anterior pituitary
Stimulates release of TSH and Modulates prolactin secretion
What is the target tissue and action of Gonadotropin-releasing hormone (GRH)? -
ANSWER-Anterior pituitary
Stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
What is the target tissue and action of Somatostatin? - ANSWER-Anterior pituitary
Inhibits release of growth hormone(GH) and TSH
What is the target tissue and action of Growth hormone-releasing hormone (GHRH)? -
ANSWER-Anterior pituitary
Stimulates release of GH
What is the target tissue and action of Corticotropin-releasing hormone (CRH)? -
ANSWER-Anterior pituitary
Stimulates release of adrenocorticotropic hormone (ACTH) and B-endorphin
What is the target tissue and action of Substance P? - ANSWER-Anterior pituitary
inhibits synthesis and release of ACTH
Stimulates secretion of GH, FSH, LH, and prolactin
What is the target tissue and action of Dopamine? - ANSWER-Anterior pituitary
Inhibits synthesis and secretion of prolactin
