Download Quiz 2 (endocrinology/thyroid) Name

BBIO 351: Principles of Anatomy & Physiology I
October 20, 2015
Quiz 2 (endocrinology/thyroid)
Name: ___Dr. C___________
1. Put the human hypothalamus, pituitary, thalamus, and thyroid gland in anatomical order
from most superior to most inferior. [2 points – 1 point off if 1 structure is out of place with the
other 3 in order, 2 points off for 2 for not having any 3 in the correct order]
MOST SUPERIOR: _____thalamus_____________
2nd-MOST-SUPERIOR: ____hypothalamus_______
3rd-MOST-SUPERIOR: ____pituitary____________
MOST INFERIOR: ____thyroid gland___________
2. All of the following are tropic hormones released by the anterior pituitary EXCEPT [2 points]
(a) adrenocorticotropic hormone (ACTH)
(b) follicle stimulating hormone (FSH)
(c) growth hormone (GH)
(d) luteinizing hormone (LH)
(e) oxytocin (OXT) – YES
(f) prolactin (PRL)
(g) thyroid stimulating hormone (TSH)
3. Draw a simple but
clear diagram showing
all well-known
stimulatory and
inhibitory interactions
among
adenocorticotropic
hormone (ACTH) from
the pituitary,
corticotropin releasing
hormone (CRH) from the
hypothalamus, and
cortisol from the adrenal
medulla cortex.
http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/adrenal/gluco.html
4 points total; 1 point for showing each of the following:
 CRH stimulates ACTH release
 ACTH stimulates cortisol release
 Cortisol inhibits CRH release
 Cortisol inhibits ACTH release
(Hypothalamus/pituitary/adrenal gland may be shown in drawing but aren’t required. If
shown, they should be secreting the correct hormones.)
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BBIO 351: Principles of Anatomy & Physiology I
October 20, 2015
4. In about 2 sentences, explain how thyroglobulin contributes to the synthesis of thyroid
hormones T3 and T4. [3 points; full credit for covering any 2 of the bullets below, 1 point off if
only 1 was covered, 2 points off for not covering any of the bullets.]
 Thyroglobulin (Tg) binds T3 and T4 precursors (monoidotyrosine [MIT] and
diiodotyrosine [DIT]).
 Thyroglobulin allows T3 and T4 precursors (monoidotyrosine [MIT] and diiodotyrosine
[DIT]) to combine to form T3 and T4.
 Thyroglobulin binds to T3 and T4.
 Via endocytosis, thyroglobulin carries T3 and T4 from the colloid into thyroid follicle cells.
 Thyroglobulin releases T3 and T4 in the lysosome.
5. Indicate with check marks whether each description below can apply to hypothyroidism,
hyperthyroidism, both, or neither. (Each row may have 0, 1, or 2 check marks.)
[8 points; each of the 16 boxes is worth 0.5 points.]
Description
Levels of T3 in the blood are low.
Levels of TSH in the blood are low.
An autoimmune disorder alters thyroid function.
Iodine uptake by the thyroid occurs more rapidly than
normal.
An altered metabolic rate can be detected by changes
in oxygen consumption.
Often goes undetected due to compensatory changes
in parathyroid hormone (PTH) from the parathyroid
gland.
Treatment involves taking synthetic thyroid hormone.
May result from a hypophysectomy.
Can be true of
hypothyroidism?
√
√
√
Can be true of
hyperthyroidism?
√
√
√
√
√
√
√
6. Testosterone, a steroid, increases expression of contractile proteins in skeletal muscle cells.
Are “2nd messengers” necessary for testosterone to have this effect? Briefly explain in about 2
sentences. [3 points]
For full credit, answer should cover 2 of the following 3 bullets. (1 point off if only 1 bullet was
covered.)
 Testosterone does not need to generate intracellular 2nd messengers because it enters
cells itself.
 Testosterone affects gene expression by binding to intracellular receptors that act as
transcription factors.
 Some of the transcribed genes probably DO affect 2nd messengers.
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BBIO 351: Principles of Anatomy & Physiology I
October 20, 2015
7. A patient of yours (possibly a human, possibly a rodent) is currently taking a medication that
causes overexpression of thyroxine-binding globulin (TBG), a protein that binds T3 and T4 in the
blood. What effects, if any, might this overexpression have on the patient? Provide about 2
sentences of informed speculation. [3 points]
I am looking mostly for sensible fact-based reasoning rather than any particular answer.
Examples might include:
 More bound T3 and T4 means less free, biologically active T3 and T4 => possible
hypothyroidism or increased synthesis of T3 and T4 to restore the usual levels.
 More bound T3 and T4 means these hormones will persist longer in the blood (won’t be
catabolized as quickly), so thyroid-induced changes may last longer than normal.
 There will be little effect because most T3 and T4 is bound to multiple proteins in blood –
a change in one of them may not do much.
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