NU 545 UNIT 3 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS LATEST UPDATE GRADED A++
How are water-soluble hormones transported?
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?
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
peptide or protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life?
because they are catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood?
For hours to days. They last longer in the blood because they are bound to carrier/transport proteins.
only free hormones can do what?
initiate changes within a target cell
,How does the concentration of binding proteins affect the concentration of free hormones in the
plasma?
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?
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?
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?
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?
cholinergic and adrenergic neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects?
,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?
ADH is produced in the hypothalmus and secreted by the posterior pituitary. ADH and the posterior
pituitary regulate osmolality.
Where does ADH act?
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?
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?
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?
, 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?
stress, trauma, pain, exercise, nausea, nicotine, exposure to heat, and drugs (morphine)
when does ADH secretion decrease?
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?
ADH acts on vasopressin (V1) receptors which cause vasoconstriction, - increasing blood pressure
What is the target tissue and action of Thyrotropin-releasing hormone (TRH)?
Anterior pituitary
Stimulates release of TSH and Modulates prolactin secretion
What is the target tissue and action of Gonadotropin-releasing hormone (GRH)?
Anterior pituitary
Stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
What is the target tissue and action of Somatostatin?
Anterior pituitary
Inhibits release of growth hormone(GH) and TSH
What is the target tissue and action of Growth hormone-releasing hormone (GHRH)?
COMPLETE SOLUTIONS LATEST UPDATE GRADED A++
How are water-soluble hormones transported?
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?
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
peptide or protein hormones are water-soluble and circulate in free (unbound) forms
why do water soluble hormones have a short half-life?
because they are catabolized by circulating enzymes. Remember they are unbound.
How long can lipid-soluble hormones remain in the blood?
For hours to days. They last longer in the blood because they are bound to carrier/transport proteins.
only free hormones can do what?
initiate changes within a target cell
,How does the concentration of binding proteins affect the concentration of free hormones in the
plasma?
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?
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?
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?
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?
cholinergic and adrenergic neurotransmitters. the major stimulus for release is glutamate.
Where is oxytocin secreted and what are its effects?
,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?
ADH is produced in the hypothalmus and secreted by the posterior pituitary. ADH and the posterior
pituitary regulate osmolality.
Where does ADH act?
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?
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?
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?
, 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?
stress, trauma, pain, exercise, nausea, nicotine, exposure to heat, and drugs (morphine)
when does ADH secretion decrease?
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?
ADH acts on vasopressin (V1) receptors which cause vasoconstriction, - increasing blood pressure
What is the target tissue and action of Thyrotropin-releasing hormone (TRH)?
Anterior pituitary
Stimulates release of TSH and Modulates prolactin secretion
What is the target tissue and action of Gonadotropin-releasing hormone (GRH)?
Anterior pituitary
Stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
What is the target tissue and action of Somatostatin?
Anterior pituitary
Inhibits release of growth hormone(GH) and TSH
What is the target tissue and action of Growth hormone-releasing hormone (GHRH)?
