Lecture 9 - Endocrine System

Question 1

Endocrine system

Answer 1

regulates metabolic activities in certain organs and tissues of the body
-produces slow and diffused effect via chemical substances called hormones

Question 2

Endocrine composition

Answer 2

endocrine cells

• clusters of cells within certain organs of the body
• ductless, richly vascular glands

Question 3

Endocrine cells

Answer 3

isolated in the epithelial lining of the difestive tract and in the respiratory system

Question 4

Endocrine glands (list them 5)

Answer 4

pituitary
pancreas
suprarenal 
thyroid
parathyroid

Question 5

Pituitary gland

Answer 5

aka hypophysis
immediately adjacent to and partially attached to the brain
-gland that produces hormones responsible for regulating growth, reproduction and metabolism
-easily falls off when dissecting
Signals function of other endocrine

Question 6

pituitary 2 subdivisions

Answer 6

develop from different embryologic sources

1. adenohypophysis
2. neurohypophysis

Question 7

Adenohypophysis (development and divisions)

Answer 7

aka anterior pit. develops from an evagination of the oral ectoderm (Rathke’s pouch), which lines the primitive oral cavity. loses contact

AKA Pars distalis- (pars anterior) -most important part of anterior
Pars interior 
Pars tuberalis (stalk)

Question 8

neurohypophysis (development and divisons)

Answer 8

aka POSTERIOR pit. develops from a neural ectoderm as a down-growth of the Diecephalan.
Maintains attachment to diencephalon of brain

median eminence
infundibulum (stalk)
pars nervosa (another name for neurohypophysis)

Question 9

Anterior Pituitary

Answer 9

produces own hormones in the pars distalis and secretes them

Question 10

Posterior pituitary

Answer 10

does not make own hormone

Secretes hormones manufactured in the hypothalamus from pars nervosa

Question 11

Pars nervosa

Answer 11

Posterior Pituitary

• stores hormones in Herring bodies
• secretes ADH, oxytocin - to stimulate contraction

Question 12

Pars distalis cell types

Answer 12

Makes its own hormone (Anterior Pituitary)
H and E stain
acidophils - stain lighter
basophils

Question 13

Pars nervosa PAS stain

Answer 13

secretory endings with PAS positive granules can be visualized

Question 14

Pars distalis basophils (name the cells and what they release)

Answer 14

• thyrotropes - secrete thyroid-stim hormone (TSH)
• gonadotropes- secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
• corticotropes - secrete adrenocorticotropic hormone (ACTH)

Question 15

Acidophils (name the cells and what they release)

Answer 15

lactotropes secrete prolactin

somatotropes - secrete growth hormone

Question 16

Pancreas (what the endocrine part is called)

Answer 16

Also has exocrine function

Endocrine portion is call Islets of Langerhans

Question 17

islets of langerhans

Answer 17

Has pale clusters on H and E stain label it in pic.
produce hormones which regulate carb metabolism
alpha cells
beta cells
delta cells

Question 18

pancrease alpha cells

Answer 18

glucagon - glucose release

Question 19

pancrease beta cells

Answer 19

insulin - glucose uptake

Question 20

pancrease delta cells

Answer 20

somatostatin - inhibitory hormone of gastric secretion

Question 21

Suprarenal (adrenal gland)( two layers)

Answer 21

on top of kidney
surrounded by a dense fibroelastic capsule of CT
- parenchyma of gland is divided into two histologgically different regions
- suprarenal (outer)cortex
-suprarenal (inner) medulla

Question 22

Suprarenal cortex

Answer 22

produces corticosteroids which are synthesized from cholesterol

Question 23

suprarenal medulla

Answer 23

functionally related to and regulated by sympathetic system

produces epinephrine and norepinephrine

Question 24

Adrenal cortex (the three zones)

Answer 24

3 zones ( know how to identify them the order)
Zona glomerulosa
zona fasciculata
zona reticularis

Question 25

zona glomerulosa

Answer 25

most peripheral region that contains cells in an ovoid configuration
Produces: aldosterone

Question 26

zona fasciculata

Answer 26

middle zone composed of cells arranged in columns separated from each other by a continuous column of capillaries
Produces: cortisol &/or corticosterone

Question 27

zona reticularis

Answer 27

situated between the fasciculata and medulla
cells organized in a loose meshwork configuration
produces androstenedione (male androgenic hormone)

Question 28

Thyroid

Answer 28

typically bi-lobed
location: superior mediastinum
2 layers of fibrous CT surround gland and blend with fascia of the neck
Gets fatty with age

Question 29

Thyroid secretion

Answer 29

T4 and T3 - under control of TSH from anterior pit.) which stimulates the rate of metabolism
calcitonin - aids in decreasing blood calcium levels and facilitates the storage of calcium in bone (decrase calcium)

Question 30

thyroid follicles

Answer 30

secretory cells (follicular epithelial cells) arranged in hollow spheres (follicles) with loose, highly vascular CT between them
epithelial cells have short microvilli on apical surface
Epithelium surrounds colloid
they make the T3 and T4 While colloid stores it

Question 31

colloid

Answer 31

contains thyroglobulin bound with T3, T4, rings of follicals surround it.
The colloid is a huge fat looking cell with a ring of cells of follicales around it

Question 32

parafollicular cells - how to visualize

Answer 32

usually located in follicular walls
large cells - stain heavily with lead hematoxylin
produce calcitonin which lowers serum calcium
KNow staining and how to visualize)
they produce the calcitonin in these

Question 33

Parathyroid glands

Answer 33

four or five glands located on the posterior surface of the thyroid

• usually lie within capsule of thyroid gland
• each gland has a thin CT capsule
• secretory cells arranged in cords and plates set in loose stroma of CT
• produce PTH

Question 34

parathyroid production

Answer 34

PTH - elevates serum calcium while reducing serum potassium via stimulation of the osteoclasts

Question 35

Cell types in parathyroid

Answer 35

Principal (chief) cells

Oxyphil cells

Question 36

Principal (chief) cells

Answer 36

central, nucleus, slightly eosinophlic cytoplasm with glycogen and lipofuscin granules
Produce: PTH

Question 37

oxyphil cells

Answer 37

larger than chief cells, very eosinophlic cytoplasm
less common than chief cells
believed to be the inactive phase of chief cells

Question 38

Herring Bodies

Answer 38

Secretary Endings that store hormones in the posteriar pituitary
Be able to identify this. Small faint pink in PAS stain