304 Chapter 15
Diabetics must constantly monitor
their blood sugar and carefully track
their activity levels and food intake.
For decades researchers have tried
to develop an “artificial pancreas,”
an automated device that would
take over this monitoring and—as
a healthy pancreas does—rapidly
supply insulin as blood levels
dropped below a set point. Recently
the FDA approved a wearable device that accomplishes this
feat. The monitor attaches to a sensor inserted under the
patient’s skin and signals the wearer when blood glucose
falls below a set point. The patient can then activate a small
insulin pump that is about the size of small cell phone. While
not perfect—currently the monitor has a “false positive” rate of
about 30 percent—it the first such device to combine a blood
glucose monitor with an insulin pump.
your Future
- has effects on body tissues in general.
a. ACTH c. LH
b. TSH d. Growth hormone - Which of the following stimulate the secretion of
hormones?
a. neural signals d. environmental cues
b. local chemical changes e. all of the above can
c. hormonal signals stimulate hormone secretion - lowers blood sugar levels; raises the level
of blood sugar.
a. Glucagon; insulin c. Gastrin; insulin
b. Insulin; glucagon d. Gastrin; glucagon - The pituitary detects a rising hormone concentration in
blood and inhibits the gland that is secreting the hormone.
This is a feedback loop.
a. positive
b. negative - Second messengers assist.
a. steroid hormones c. only thyroid hormones
b. nonsteroid hormones d. both a and b - Match the hormone source with the closest description.
adrenal cortex a. affected by day length
adrenal medulla b. cortisol source
thyroid gland c. roles in immunity
parathyroids d. adjust(s) blood calcium
pancreatic islets level
pineal gland e. epinephrine source
thymus f. insulin, glucagon
g. hormones require iodine - Match the endocrine control concepts.
oxytocin a. released by the anterior
ACTH pituitary and affects the
ADH adrenal gland
growth hormone b. influences extracellular
estrogen fluid volume
c. has general effects on
growth
d. triggers uterine contractions
e. a steroid hormone
CritiCaL thinKing
- Addison’s disease develops when the adrenal cortex does
not secrete enough mineralocorticoids and glucocorticoids.
President John F. Kennedy was diagnosed with the disease
when he was a young man. Before he started treatment
with hormone replacement therapy, he was hypoglycemic
and lost weight. Which missing hormone was responsible
for his weight loss? How might Addison’s disease have
affected his blood pressure?
© Elizabeth Musar
- A physician sees a patient whose symptoms include
sluggishness, depression, and intolerance to cold. After
eliminating other possible causes, the doctor diagnoses
a hormone problem. What dis order fits the symptoms?
Why does the doctor suspect that the underlying cause
is a malfunction of the anterior pituitary gland? - Marianne has type 1 diabetes. One day, after accidentally
injecting herself with too much insulin, she starts to shake
and feels confused. Following her doctor’s suggestion,
she drinks a glass of orange juice—a ready source of
glucose—and soon her symptoms subside. What caused
her symptoms? How would a glucose-rich snack help? - Secretion of the hormone ADH may decrease or stop if the
pituitary’s posterior lobe is damaged, as by a blow to the
head. This is one cause of diabetes insipidus. People with this
form of diabetes excrete so much dilute urine that they
may become seriously dehydrated. Where are the target
cells of ADH?
Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).