Block 1 Histology Md1 Endocrine System 1 Part D

Front 1

1. Neurogenic diabetes insipidus occurs when the secretion of

Back 1

ADH is reduced or absent.

Polyuria is a common clinical finding.

Patients with diabetes insipidus can excrete up to =

Hint 1

20 L of urine in 24 hours.

Front 2

Neurogenic diabetes insipidus is caused by =

Back 2

head injury
invasive tumor

damaging the =

Hint 2

hypothalamic hypophysial system
autoimmune

destruction of vasopressin-secreting neurons.

Front 3

Nephrogenic diabetes insipidus occurs in = 2ct

Back 3

certain chronic renal diseases that are nonresponsive to vasopressin
or
as a result of genetic defects in renal receptors for vasopressin

Front 4

The most common disease of the pituitary is

Back 4

pituitary adenoma.

These tumors are classified as benign

Hint 4

they do not invade adjacent tissues. However they may have serious or even fatal consequences.

Front 5

a tumor of corticotrophs secretes excess =

Back 5

ACTH

stimulating the adrenals to produce large quantities of corticosteroid, leading to =

Hint 5

Cushing's disease.

Front 6

Cushing's disease. =

Back 6

excess ACTH

Front 7

Tumors of somatotrophs produce excess =

Back 7

growth hormone causing gigantism in children or acromegaly in adults.

Front 8

Some pituitary adenomas produce no hormones but grow locally so large that they grow upwards out of the =

Back 8

sella turcica to compress and damage the overlying =

Hint 8

optic chiasma
and nerves, leading to vision disturbance and eventual blindness.

Front 9

what is above the pituitary =
2ct

Back 9

sella turcica
optic chiasma
nerves

Front 10

vision disturbance and eventual blindness.
could be due to what kind of benign tumor =

Back 10

pituitary adenoma

Front 11

panhypopituitarism

Back 11

The pituitary gland can in rare cases be destroyed by disease blocking its arterial supply, leading to necrosis of the cells and failure of hormone output

Front 12

The pituitary gland can in rare cases be destroyed by disease blocking its arterial supply, leading to necrosis of the cells and failure of hormone output

Back 12

panhypopituitarism

Front 13

Each gland is covered with a thick connective tissue capsule from which trabeculae extend into the parenchyma.

The stroma consists mainly of a rich network of reticular fibers that supports the secretory cells.

The secretory parenchymal tissue is organized into
=

Back 13

a yellowish outer cortex (80% to 90% of the gland)

a reddish inner medulla (10% to 20%).

Front 14

adrenal cortex and the adrenal medulla can be considered two organs with distinct origins, functions, and morphological characteristics that became united during embryonic development.

They arise from different germ layers. =

Back 14

cortex arises from the =

whereas the cells of the medulla derive from the =

Hint 14

coelomic epithelium
(mesodermal mesenchyme),

neural crest
that migrate into the developing gland.

Front 15

The adrenal cortex has a similar embryological origin to the

Back 15

gonads

Front 16

adrenal medulla has a similar origin to that of the sympathetic nervous system and may be considered as a highly specialized adjunct of this system (It produces

Back 16

catecholamines

Front 17

The adrenal glands are supplied with blood by the

Back 17

superior
middle
inferior
suprarenal arteries

Front 18

The adrenal glands are supplied with blood by the superior, middle and inferior suprarenal arteries.
These branch to give rise to three principal patterns of blood distribution:

Back 18

Capsular

Cortical

Medullary

Hint 18

arteries that supply the capsule

arteries that supply the cortex and then drain into the fenestrated medullary capillaries.

arteries that traverse the cortex without branching, traveling within the trabeculae and bring the arterial blood to medullary capillaries (venous sinusus).

Front 19

medulla has a dual blood supply,

Back 19

arterial blood from medullary arteries

venous blood from the cortical capillaries.

The venules that arise from these drain into =

Hint 19

adrenomedullary collecting veins.

Front 20

T/F
There are veins & lymphatics in the adrenal cortex

Back 20

False

There are NO
veins or lymphatics
in the adrenal cortex

Front 21

adrenal glands
Steroid-secreting cells

the plasma membrane and do not require the specialized process of

Back 21

not require the specialized process of exocytosis for their release.

Front 22

adrenal cortex consists of three concentric zones % of space =

Back 22

zona glomerulosa (15% of cortical volume).

the zona fasciculata (80% of cortical volume).

zona reticularis (5 – 7% of cortical volume).

Front 23

____________
stimulates both the growth of the zona glomerulosa and the synthesis of aldosterone

Back 23

Angiotensin II

Front 24

Zona glomerulosa
lacks the enzyme _____________
α-hydroxylase and, therefore, cannot produce cortisol or sex steroids. =

Back 24

17 α-hydroxylase

Front 25

it lacks the enzyme 17 α-hydroxylase and, therefore, cannot produce =
2ct

Back 25

cortisol
or
sex steroids.

Front 26

Zona fasciculata

It is formed by $_____ cells, with the structural features of steroid-producing cells arranged in longitudinal cords (1-2 cell thick) separated by cortical ________ _________

Back 26

cuboidal

fenestrated capillaries.

Front 27

containing steroidogenic enzymes

Back 27

he steroid hormone precursor cholesterol

mitochondria with tubular cristae

well-developed smooth endoplasmic reticulum

Front 28

17α-hydroxylase necessary for the production of glucocorticoids-cortisol-and the enzyme 17,20-hydroxylase, required for the production of =

Back 28

sex hormones.

Front 29

sex hormones. need what chemicals that the Zona Fasciculata does not have =

Back 29

17α-hydroxylase
glucocorticoids-cortisol
-enzyme 17,20-hydroxylase,

Front 30

Zona reticularis

Cells of the zona reticularis form an =

Back 30

anastomosing network of short cellular cords separated by__________
capillaries.

Hint 30

fenestrated

Front 31

The cells of this zone are __________ , due to abundant lysosomes, large lipofuscin granules, and fewer lipid droplets.

Back 31

acidophilic

Front 32

Although cells of the zona fasciculata can synthesize androgens, the primary site of adrenal sex hormone production is the

Back 32

zona reticularis

Front 33

DHEA sulfate
is synthesized in the =

Back 33

zona reticularis.

Front 34

DHEA and androstenedione are weak or strong =

Back 34

weak androgens, they can be converted to testosterone and even to estrogen in peripheral tissues.

Front 35

_______ & ______ are weak androgens, they can be converted to testosterone and even to estrogen in peripheral tissues. =

Back 35

DHEA
androstenedione

Front 36

adrenal gland is the major source of androgens in women

these androgens stimulate the growth of =

Back 36

pubic and axillary hair during puberty

Front 37

Adrenal cortex: Hormones
mineralocorticoids act mainly on the =

Back 37

distal renal tubules
gastric mucosa
colon
salivary
sweat glands

stimulating the reabsorption of =

Hint 37

sodium by epithelial cells.

Front 38

glucocorticoids affect the metabolism of carbohydrates by stimulating both the production of glucose from amino acids or fatty acids (gluconeogenesis) and the conversion of =

Back 38

glucose into glycogen.
+

Hint 38

Cortisol may decrease the uptake of glucose by cells, which together with the increased production of glucose may lead to hyperglycemia or to the maintenance of adequate levels of glucose in the blood during hunger and stress reactions.

In the skin, muscle and adipose tissue, glucocorticoids not only decrease synthetic activity but also promote protein and lipid degradation.

Glucocorticoids also suppress the immune response by destroying circulating lymphocytes, inhibiting mitotic activity in lymphocyte-forming organs, and controlling secretion of cytokines.

Front 39

Dehydroepiandrosterone (DHEA) is secreted in significant physiological quantities by the =

Back 39

adrenal cortex.

Front 40

Because of the feedback mechanism of adrenal cortex control, patients who are treated with corticoids for long periods should never stop taking these hormones suddenly: secretion of ACTH in these patients is inhibited, and thus the cortex will not be induced to produce corticoids, causing a severe misbalance in the levels of

Back 40

sodium
potassium

Front 41

Destruction of both adrenals
hypoadrenalism

called =

Back 41

Addison's disease

Front 42

Addison's disease

called =

Back 42

Cushing's syndrome

mineralocorticoids
(producing Conn's syndrome).

Front 43

excess hormone may be produced by a benign tumor (adrenal cortical adenoma) or a malignant tumor (adrenal cortical carcinoma), or by diffuse hyperplasia

Back 43

hirsutism or virilization are frequently present.

Front 44

Adrenal medulla
adrenal medulla is composed of

Back 44

polyhedral cells
arranged
in cords or clumps and supported by a reticular fiber network.

Front 45

Adrenal medulla

A profuse capillary supply intervenes between adjacent cords, and there are a few

Back 45

parasympathetic ganglion cells.

Front 46

Adrenal medulla
medullary cells arise from

Back 46

NCC

Thus, the cells of the adrenal medulla can be considered modified

Hint 46

modified sympathetic postganglionic neurons

that have lost their axons and dendrites during embryonic development and have become secretory cells.

Front 47

adrenal medulla contains _______ cells

Back 47

chromaffin cells

so named because of their ability to acquire a

Hint 47

brown coloration when exposed to an aqueous solution of potassium dichromate. This reaction is due to the oxidation of catecholamines by chrome salts to produce a brown pigment.

Front 48

Adrenal medulla

Minimal secretion of

Back 48

dopamine

Front 49

Two different chromaffin cell types are present.
=

Back 49

About 80% of the cells produce epinephrine and 20% synthesize norepinephrine.

Norepinephrine is stored in granules with a dense eccentric core.

Epinephrine-containing granules are smaller and occupy the less dense central core.

Front 50

Cortisol also promotes epinephrine synthesis in the medulla. At high levels, cortisol can promote the upregulation of

Back 50

phenylethanolamine N-methyl transferase (PNMT),

thereby increasing

Hint 50

epinephrine synthesis and secretion.

Front 51

Fight-or-flight response
Secretion of these substances is mediated by

Back 51

preganglionic fibers

Hint 51

Epinephrine and norepinephrine are secreted in large quantities in response to intense emotional reactions, such as fright, that are part of an alarm reaction (the fight-or-flight response).

Secretion of these substances is mediated by the preganglionic fibers that innervate medullary cells.

Vasoconstriction, hypertension, changes in heart rate, and metabolic effects such as elevated blood glucose result from the secretion and release of catecholamines into the bloodstream.

During normal activity, the medulla continuously secretes small quantities of these hormones.


**Clinical significance: One disorder of the adrenal medulla is pheochromocytoma, a tumor of its cells that causes transient elevations of blood pressure. These tumors can also develop in extramedullary sites.