Histology II: endocrine organs

Question 1

The endocrine- and nervous system do what together?

Answer 1

regulate metabolic activity of the different organs and tissues of the body so as to maintain homeostasis.

Question 2

Endocrine glands secrete the hormones where?

Answer 2

directly into the blood or lymph

Question 3

Name 10 endocrine glands.

Answer 3

adrenal glands
hypophysis (pituitary)
hypothalamus

pancreas (islets in the pancreas)
parathyroid glands
pineal gland
placenta

testes and ovaries
thymus
thyroid gland

Question 4

Another name for the hypophysis.

Answer 4

pituitary gland

Question 5

Which endocrine glands can be found in the brain?

Answer 5

hypothalamus
pineal gland
pituitary gland (hypophysis)

Question 6

Name the “central” endocrine organs.

Answer 6

hypophysis

hypothalamus

Question 7

Name the peripheral endocrine organs.

Answer 7

adrenal glands
parathyroid glands
pineal gland
thyroid gland

Question 8

Name the endocrine organs that have functions in addition to hormone production and secretion.

Answer 8

pancreas
placenta
testes and ovaries
thymus

Question 9

Where is the pituitary gland located?

Answer 9

centrally located at the base of the brain

Question 10

The hypophysis has what two functional components?

Answer 10

Adenohypophysis

Neurohypophysis

Question 11

What is the adenohypophysis?

Answer 11

the anterior lobe of the pituitary gland, the glandular epithelial tissue part

Question 12

What is the neurohypophysis?

Answer 12

the posterior lobe of the pituitary gland, the neural secretory tissue part

Question 13

The neurohypophysis produces what two hormones?

Answer 13

Oxytocin

Vasopressin/ADH

Question 14

What is the function of oxytocin?

Answer 14

stimulates activity of mammary glands
stimulates contractions of the uterus
promotes maternal behavior

Question 15

What is the function of vasopressin?

Answer 15

maintains osmolality
decreases urine volume
increases blood pressure

Question 16

Another name for vasopressin.

Answer 16

antidiuretic hormone (ADH)

Question 17

The adenohypophysis produces what 6 hormones?

Answer 17

Adrenocorticotropic hormone (ACTH) 
Follicle-stimulating hormone (FSH) 
Growth hormone (GH) 
Luteinizing hormone (LH) 
Prolactin (PRL)
Thyroid stimulating hormone or thyrotropin (TSH)

Question 18

Function of PRL?

Answer 18

promotes mammary gland development and milk production

Question 19

Function of LH?

Answer 19

regulates final maturation of ovarian follicle, androgen secretion in testis

Question 20

Function of TSH?

Answer 20

regulates growth of thyroid epithelial cells and regulate the production of hormones by the thyroid gland

Question 21

Function of GH?

Answer 21

stimulates body growth

Question 22

Function of ACTH?

Answer 22

stimulates secretion of cortisol in adrenal cortex

Question 23

Function of FSH?

Answer 23

stimulates follicular development of the ovary and spermatogenesis in testis

Question 24

Where is the hypothalamus located?

Answer 24

Located in the middle at the base of the brain.

Question 25

Function of the hypothalamus?

Answer 25

Regulates activity of the hypophysis.

Question 26

What is the diencephalon?

Answer 26

The diencephalon connects the midbrain to the forebrain. It is located deep within the brain and comprises the epithalamus, thalamus, subthalamus and hypothalamus.

Question 27

Where is the pineal gland located?

Answer 27

deep in the brain in an area called the epithalamus, where the two halves of the brain join. The epithalamus is a part of the diencephalon.

Question 28

Function of the pineal gland?

Answer 28

receive information about the state of the light-dark cycle from the environment and convey this information to produce and secrete the hormone melatonin

Question 29

Describe the location of the pineal gland in reptiles and lower vertebrates.

Answer 29

the pineal lies at or near the skin surface where it functions as a photoreceptor organ (“third or parietal eye”)

Question 30

Describe the function of the pineal gland in reptiles and lower vertebrates.

Answer 30

functions as a photoreceptor organ secreting the hormone melatonin which lightens skin color by its action on melanophores, pigmented cell analogues to melanocytes in mammals

Question 31

Where is the thyroid gland located?

Answer 31

Located in the anterior neck region, just caudal to the larynx, adjacent to the lateral surface of the trachea.

Question 32

Main parts of the thyroid?

Answer 32

2 lobes that are separated from each other by fibrous connective tissue trabeculae

Question 33

Thyroid follicles filled with?

Answer 33

colloid

Question 34

The parenchyma of the thyroid consists of?

Answer 34

follicles, lined with simple epithelium

Question 35

The epithelial cells between thyroid follicles form what?

Answer 35

parafollicular islets

Question 36

What part of the thyroid is responsible for production of thyroxine?

Answer 36

Follicular cells

Question 37

What part of the thyroid is responsible for production of calcitonin?

Answer 37

Parafollicular islets

Question 38

Calcitonin function?

Answer 38

main actions of calcitonin are to increase bone calcium content and decrease the blood calcium level when it rises above normal. also lowers blood phosphorus levels when they rise above normal

Question 39

Where are the parathyroid glands located?

Answer 39

lie just behind the thyroid gland closely associated with it

Question 40

Parathyroid function?

Answer 40

produces parathyroid hormone, which plays a key role in the regulation of calcium levels in the blood

Question 41

Main diff. between the function of parathyroid hormone and calcitonin?

Answer 41

Parathyroid hormone acts to increase blood calcium levels, while calcitonin acts to decrease blood calcium levels.

Question 42

Where are the adrenal glands located?

Answer 42

on the upper poles of the kidneys embedded in the perirenal fat

Question 43

How many parathyroids are there generally?

Answer 43

4

Question 44

Describe the morphology of the adrenals.

Answer 44

covered by thick connective tissue capsule; | the secretory parenchymal tissue is organized in cortical and medullary regions

Question 45

Where is cortisol produced?

Answer 45

the adrenal cortex

Question 46

What zones are the adrenal cortex divided into based on what?

Answer 46

zona glomerulosa zona fasciculata zona reticularis based on location and structure of the epithelial cells and sinusoids

Question 47

Describe zona glomerulosa

Answer 47

thin subcapsular zone; | synthesizes mineralocorticoids, mainly aldosterone and deoxycorticosterone

Question 48

Describe zona fasciculata

Answer 48

occupies most of the adrenal cortex; | secretes glucocorticoids, mainly cortisol and corticosterone

Question 49

Describe zona reticularis

Answer 49

composed of cells arranged in an anastomosing network of clumps and columns with a capillary network; produces androgenic steroids and in small amounts, glucocorticoids

Question 50

What is the adrenal medulla composed of?

Answer 50

``` a parenchyma called chromaffin cells (are modified neurons which have a secretory function) connective tissue, numerous sinusoidal blood capillaries, and nerves. ```

Question 51

Function of chromaffin cells?

Answer 51

in effect, modified neurons which have a secretory function, produce norepinephrine and epinephrine.

Question 52

What is the endocrine component of the pancreas?

Answer 52

Islets of Langerhans

Question 53

Where can you find Islets of Langerhans more specifically?

Answer 53

scattered throughout the pancreas but are more numerous in tail region

Question 54

Histological appearance of islets of langerhans?

Answer 54

appear as clusters of pale-stained cells surrounded by more intensely staining pancreatic acini.

Question 55

What are the cell types in Islets of Langerhans?

Answer 55

B (beta) cells (approx. 70%) A (alpha) cells (20%) D (delta) cells (5-10%) PP cells (1-2%)

Question 56

What do beta islet cells secrete?

Answer 56

insulin

Question 57

What do alpha islet cells secrete?

Answer 57

glucagon

Question 58

What do delta islet cells secrete?

Answer 58

somatostatin

Question 59

Somatostatin function?

Answer 59

inhibits glucagon and insulin release

Question 60

What do PP islet cells secrete?

Answer 60

pancreatic polypeptides

Question 61

Pancreatic polypeptide function?

Answer 61

It can inhibit gallbladder contraction and pancreatic exocrine secretion, but its role in the metabolism of nutrients is uncertain.