Block 1 Histology Md1 Endocrine System 2 Part B

Front 1

Thyroid gland
exocrine phase consists of

Back 1

~uptake of inorganic iodide from the blood
(which is driven by what energy process =

~the synthesis of thyroglobulin

Hint 1

(ATP-driven iodide pump )

Front 2

uptake of inorganic iodide from the blood
synthesis of thyroglobulin

is what phase =

Thyroid gland

Back 2

exocrine phase

Front 3

Thyroid gland
synthesis of thyroglobulin

Iodide is oxidized by thyroid

Back 3

peroxidase

and is transported into the follicle cavity by=

Hint 3

anion transporter called =





pendrin

Front 4

Thyroid gland
the incorporation of iodine into tyrosyl residues of thyroglobulin is also by

Back 4

thyroid peroxidase

Front 5

Thyroid gland
the incorporation of iodine into ______ residues of thyroglobulin is also by thyroid peroxidase.

Back 5

tyrosyl

Front 6

Thyroid gland

The endocrine phase starts with the TSH-stimulated ___________ of iodinated thyroglobulin into the _________ cell:

Back 6

.endocytosis

follicular

Thyroid hormones are then released across the basal lamina of the thyroid follicular

Front 7

Thyroid gland


T3 has a shorter half-life (__ hours), is more potent, and less abundant than T4.

Back 7

18

Front 8

Thyroid gland

The half-life of T4 is _-_ days and represents about __% of the secreted thyroid hormones.

Back 8

5-7 days

90%

Front 9

Thyroid gland

#2 Graves' disease, the patient produces autoantibodies
(called__________________________), produced by plasma cells derived from sensitized T cells against ____ receptors present at the basal surface of thyroid follicular cells, bind to the receptor and mimic the effect of =

Back 9

thyroid-stimulating immunoglobulins or TSI’s

TSH

TSH.

Front 10

#1 (nodular hyperplasia).

Back 10

tumor-like nodule
follicle epithelial cells constantly synthesize and secrete thyroid hormone without a significant inactive storage phase (nodular hyperplasia).

Front 11

Thyroid gland

Both of these patterns of hyperplasia produce the disease called ___________ =.

Back 11

thyrotoxicosis

Front 12

are typical clinical features of =
Enlargement of the thyroid gland (goiter)
, bulging eyes (exophthalmos),
tachycardia,
warm skin,
fine finger tremors

Back 12

nodular hyperplasia
Graves' disease

Front 13

Hypothyroidism

S/S =

Back 13

decrease in the basal metabolic rate
hypothermia
cold intolerance
Decreased sweating
cutaneous vasoconstriction make the skin dry and cool

Cardiac output is reduced
pulse rate slows

Front 14

In the fetus, a lack of thyroid hormone causes =

Back 14

cretinism

Front 15

Hashimoto's disease is an ____________ disease
associated with ____________.

Back 15

autoimmune

hypothyroidism

Front 16

Hashimoto's Dz
is caused by autoantibodies targeted to thyroid __________ and ___________

Back 16

peroxidase
thyroglobulin

Front 17

The parathyroid glands are small oval endocrine glands closely associated with the

Back 17

thyroid gland.

on the ______ surface

Hint 17

posterior

Front 18

Parathyroid glands

They are located usually in the capsule that covers the lobes of the thyroid. Sometimes they are embedded in the thyroid gland

Back 18

.

Front 19

Each parathyroid gland is contained within a __ ______ =

Back 19

CT capsule.

Front 20

Parathyroid glands

parenchyma of the parathyroid glands consists of two cell populations supplied by sinusoidal capillaries

Back 20

1 the more numerous chief or principal cell.
the oxyphil or acidophilic cell.

2 Cells are arranged in cordlike or follicular-like clusters.

Front 21

Parathyroid glands

Chief or principal cells contain =

Parathyroid hormone is stored in =

Back 21

cytoplasmic granules with parathyroid hormone.

secretory granules.

also observed in chief cells. =

Hint 21

Glycogen inclusions

Front 22

Parathyroid glands

Ca2+-sensing receptors (CaSR) are present in the plasma membrane of

Back 22

chief cells.

Front 23

Serum Ca2+binding to the extracellular region of the CaSR triggers the release of intracellular signals causing =

Back 23

suppressing secretion of
parathyroid hormone,

with the consequent decrease in the serum Ca2+ concentration.

Front 24

When the serum Ca2+ concentration decreases, the secretion of parathyroid hormone is what =

Back 24

stimulated,

resulting in an increase in serum Ca2+

Front 25

Oxyphil or acidophilic cells contain abundant mitochondria, which give this cell its typical stain. This cell type may represent transitional chief cells.

Back 25

.

Front 26

Oxyphil cells tend to occur in nodules, These cells do not secrete PTH and increase in number with age.

Back 26

.

Front 27

With increasing age, Chief cells are replaced with adipocytes. Adipose cells constitute more than __ % of the gland in older people

Back 27

50%

Front 28

Parathyroid hormone regulates the ___ and____ balance in _____ by acting on two main sites: =

Back 28

Ca2+

PO4 3-

blood

bone tissue
uriniferous tubules

Front 29

Parathyroid hormone regulates the Ca2+

The bone tissue, where it stimulates =

Back 29

resorption of mineralized bone by osteoclasts and the release of Ca2+ into the blood. Serum Ca2+ levels normally average =

Hint 29

9.5 mg/dL.

Front 30

Parathyroid hormone regulates the Ca2+

uriniferous tubules, where it stimulates

Back 30

resorption of Ca2+ and activates the production of active vitamin ____ =

Hint 30

D

Front 31

Parathyroid hormone is secreted into the blood and has a half-life of about

Back 31

5 minutes.

Front 32

The commonest cause of hyperparathyroidism is a benign tumor of one of the parathyroid glands =

Back 32

parathyroid adenoma

) which constantly produces excessive parathormone, unresponsive to normal feedback mechanisms related to the blood calcium levels.

Front 33

The excess parathormone stimulates excessive =

Back 33

osteoclastic erosion of bone with the release of bone calcium into the blood to produce =

The results include bone pain with X-ray abnormalities and an increased risk of _____ ______

This pattern is called ___________ ___________

Hint 33

hypercalcemia. (osteitis fibrosa cystica)
***

kidney stones.

primary hyperparathyroidism.

Front 34

***
The excess parathormone stimulates excessive osteoclastic erosion of bone with the release of bone calcium into the blood to produce hypercalcemia.*
*** (osteitis fibrosa cystica)

The results include bone pain with X-ray abnormalities and an increased risk of kidney stones.

This pattern is called primary =

Back 34

hyperparathyroidism.

Front 35

__________________ is a secondary response of all the parathyroid glands to a persistent low serum calcium level in patients with kidney failure who are constantly losing calcium in their urine.

Back 35

Secondary hyperparathyroidism

The feedback mechanism is triggered and all of the parathyroids become =

Hint 35

enlarged (parathyroid hyperplasia)

Front 36

Hypoparathyroidism is rare, and is usually due to accidental removal of parathyroid glands during surgery of the thyroid gland.

Back 36

.Within 24 to 48 hours of surgical removal of the parathyroid glands, hypocalcemia, increased excitability of nervous tissue, including paresthesia (sensation of pins and needles), and attacks of tetany or epilepsy occur. Administration of parathyroid hormone corrects these alterations.

Front 37

Pineal gland = aka

Back 37

(epiphysis cerebri
pineal body

lies in the midline of the =

It represents an evagination of the posterior part of the

Hint 37

brain

roof of the third ventricle.

Front 38

The pineal gland is an _______ organ formed by cells with a ______________ function.

Back 38

endocrine

neurosecretory

Front 39

The pineal gland is connected to the brain by a stalk, but there are no direct nerve connections of the pineal gland with the brain. Instead, post-ganglionic sympathetic nerve fibers derived from the superior cervical ganglia supply the pineal gland.

Back 39

.

Front 40

The function of the pineal gland is regulated by =

Back 40

sympathetic nerves.

Front 41

The pineal gland is covered by pia mater.

Connective tissue septa containing blood vessels and unmyelinated nerve fibers originate in the pia mater and penetrate the pineal tissue.

Along with the capillaries, they surround the cellular cords and follicles, forming irregular lobules.

Back 41

.

Front 42

Two cell types form the pineal gland

Back 42

pinealocytes
glial-like interstitial cells (astrocytes)

Front 43

Pineal gland
Like the anterior hypophysis, the pineal gland lacks a =

Back 43

blood-brain barrier.

function of pinealocytes is regulated by

Hint 43

β-adrenergic receptors

Front 44

metabolic activity of pinealocytes is inhibited by

Back 44

β-adrenergic antagonists.

Calcification starts early in childhood and becomes evident in the second decade of life.

Front 45

T/F


Calcification has no known effect on the function of the pineal gland.

Back 45

T

A calcified pineal gland is an important radiographic =

Hint 45

marker of the midline of the brain.

Front 46

when is melatonin content of the pineal gland is highest.

Back 46

During night (with complete darkness

Front 47

The pineal gland secretes

Back 47

melatonin, the hormone of darkness.

Front 48

Melatonin is released into the

Back 48

general circulation
to act on the =

Hint 48

hypothalamus
hypophysis
to induce sleepiness.

in many species to inhibit gonadotropin and growth hormone secretion

Front 49

Circadian clock, an endogenous oscillator controlling circadian rhythms A 24-hour biological circadian clock regulates sleep and feeding patterns and is linked to the light-dark cycle or sleep-wake cycle.

Back 49

.

Front 50

A tumor of the pineal gland (pinealoma) is associated with =

Back 50

Precocious puberty

Front 51

Precocious puberty is characterized by the onset of =

Back 51

androgen secretion and spermatogenesis in boys before the age of_ _or __ years

and the initiation of estrogen secretion and cyclic ovarian activity in girls before age =

Hint 51

9-10


8

Front 52

Precocious puberty is probably caused by the effect of the tumor on the function of the hypothalamus rather than by a direct effect of pineal tumors on sexual function.

Back 52

.