Micro Anat Lecture 2 Endocrine System

Front 1

What is the difference in the way the CNS and ENS govern activities

Back 1

CNS: rapidly through the transmission of electrical signals
ENS: slower and more sustained by releasing hormones

Front 2

What are the endocrine gland organs

Back 2

pituitary gland
pineal gland
thyroid gland
parathyroid gland
adrenal gland

Front 3

what are the endocrine systems that exist as collections of cells within other glands

Back 3

pancreatic islets
neurosecretory neurons in the hypothalamus
male and female repro endo cells

Front 4

What is the major difference between water insolule and water soluble hormones

Back 4

insoluble: can cross cell membrane, move to nucleus, bind to portion of DNA
soluble: cannot cross cell membrane, bind to receptors on cell membrane

Front 5

what type of hormones are testosterone, estradiol, and progesterone

Back 5

water insoluble

Front 6

what type of hormones are polypeptides and proteins (insulin, FSH)

Back 6

water soluble

Front 7

what can be considered the most important gland of the endocrine system and why

Back 7

pituitary
provides hormones for the control of growth, metabolism, and reproduction

Front 8

What are the two portions of the pituitary gland

Back 8

adenohypophysis
neurohypophysis

Front 9

What is the difference between exocrine and endocrine glands

Back 9

exo: secrete their products via ducts or directly onto the surface of target cell
endo: ductless glands, secrete into blood or lymphatic sys for delivery

Front 10

Define Autocrine

Back 10

the signaling cell is its own target, thus the signaling cell stimulates itself

Front 11

Define Paracrine

Back 11

the target cell is located in the vicinity of the signally cell, so the signaling substance does not have to enter the blood

Front 12

What is secreted from endo cells

Back 12

hormones
ex: peptides, proteins, modified aas, steroids, lipids, glycoproteins

Front 13

what is the difference between constitutive and regulated secretions

Back 13

C: continuous release of secretory product without intermediate storage and without req a prompt by signaling molecules
R: concentrate and store secretory products until proper signaling molecules for release are received

Front 14

in general, how are secretory cells of endocrine glands arranged

Back 14

into cords of cells or into follicles

Front 15

embryologically, where does the pituitary arise from

Back 15

neuralectoderm envaginates to meet an invagination of the roof of the mouth (oral ectoderm)

Front 16

what portion of the pituitary is rostral and caudal

Back 16

rostral: adenohypophysis
caudal: neurohypophysis

Front 17

which portion of the pituitary is epithelial in appearance and glandular in function

Back 17

adenohypophysis

Front 18

what are the subdivisions of the adenohypophysis, which one is the largest portion

Back 18

pars distalis (largest)
pars intermedia
pars tuberalis

Front 19

what are the subdivisions of the neurohypophysis

Back 19

pars nervosa
infundibulum
median eminence

Front 20

what are the main cell types within the pars distalis

Back 20

acidophils: larger than chromophobes, granular/acidophilic cytoplasm
basophils: larger than acidophils, basophilic cytoplasm
chromophobes: small round cells, scant cytoplasm, no granules

Front 21

what do acidophils (A or alpha cells) secrete

Back 21

growth hormone (somatotropin) from somatotrops
prolactin form mammotrops

Front 22

what do basophils secrete

Back 22

thyroid secreting hormone (TSH) from thyrotrops
FSH, and LH from gonadotrops

Front 23

what are POMC cells

Back 23

a precursor molecule
produced by basophils
secrete ACTH and beta-LPH in the pars distalis which are then further cleaved in the pars intermedia

Front 24

what subsection of the adenohypophysis is highly vascularized

Back 24

pars tuberalis

Front 25

what is the hypothalamohypophyseal tract

Back 25

term that groups the neurohypophysis and hyothalamus together,
consists of axons derived from neurons and their cell bodies and are housed in the hypothalamus

Front 26

what are the axons of the hypothalamohypophyseal tract supported by

Back 26

pituicyte cells

Front 27

what do the neurons in the hypothalamohypophyseal tract produce

Back 27

oxytocin (uterine smooth m contraction and milk let down)
ADH (water resorption in kidneys and vasoconstriction)
neurophysins (carriers of ADH and oxytocin)

Front 28

what are herring bodies

Back 28

accumulations of neurosecretory granules along the length of the axons in the hypothalamohypophyseal tract

Front 29

what are the main functions of the hypothalamus and pituitary

Back 29

they maintain homeostasis with the hypothalamus acting as the master controller

Front 30

how does the hypothalamus act as the master controller

Back 30

secretes neuroendocrine hormones that stimulate or inhibit the anterior pituitary which will then turn on or off various other endocrine functions in organs

Front 31

explain the hypophyseal portal system

Back 31

hypothalamus delivers neuroendocrine hormones to primary capillary plexus where they are delivered to the pituitary secretory cells within the pars distalis
then secrete hormones to a 2ndary capillary plexus for distribution to the rest of the body via the hypophyseal vein

Front 32

what makes up 25% of the pars nervosa

Back 32

support cells called petuicytes

Front 33

what does the pars distalis secrete

Back 33

TSH
FSH
LH
prolactin
growth hormone
POMC

Front 34

what does pars intermedia secrete

Back 34

MSH
endorphins
y-LPH
ACTH

Front 35

what does the pars nervosa secrete

Back 35

oxytocin
ADH
neurophsins

Front 36

what are the adrenal glands derived from

Back 36

mesoderm and neural crest ectoderm

Front 37

what does the adrenal gland function in

Back 37

homeostasis

Front 38

is the adrenal gland vascularized

Back 38

yes, highly vascularized

Front 39

what are the 3 circulation patterns of the adrenal glands

Back 39

1) subscapsular capillary plexus (drains into subscapsular veins)
2) cortical plexus (drains into the medulla
3) arterioles that transverse the cortex to supply the medulla and drain into the medullary veins)

Front 40

what nerves innervate the adrenal gland

Back 40

parasympathetic and sympathetic innervate the cortex and medulla
sympathetic goes directly to the medualla

Front 41

where are the lymph vessels in the adrenal gland

Back 41

in the CT capsule and interstitial tissue

Front 42

what kind of CT forms the capsule of the adrenal gland

Back 42

dense irregular CT

Front 43

what are the zones of the adrenal cortex

Back 43

Zona glomerulosa
Zona fasciculata
Zona reticularis

Front 44

decribe the cells of the zona glomerulosa in the cortex of the adrenal gland

Back 44

has curved cords (arcades) of cells resembling glomeruli of the kidney
cells are columnar or polyhedral
evenly eosinophilic, less foamy and the nuclei are smaller than adjacent zones

Front 45

what is the widest zone of the adrenal cortex

Back 45

zona fasciculata

Front 46

what do the cells within the zona glomerulosa secrete

Back 46

mineralocorticoids; aldosterone is the most important

Front 47

what do mineralocortidcoids do

Back 47

maintian electrolyte balance

Front 48

what do the cells in the zona fasciculata secrete

Back 48

corticosteroids; glucocorticoids

Front 49

what does cortisol do

Back 49

causes increases blood glucose, helps maintain ECF volume during stress, anti-inflammatory properties

Front 50

what do the cells in the zona reticularis secrete

Back 50

a precursor hormone that can be metabolized to testosterone and estradiol

Front 51

What are the major constituents of the adrenal medulla

Back 51

glandular cells (chromaffin or phenochrome cells)
ganglion cells
venules
capillaries

Front 52

Describe chromaffin cells

Back 52

basophilic
contain fine chromaffin granules
polarized (one pole opposing a capillary and the other pole a venule)

Front 53

what do chromaffin cells secrete
what about in cows

Back 53

epinephrine and norepinephrine
cows: central cells secrete norepi and towards the outside epi

Front 54

what nerve stimulates chromaffin secretion

Back 54

preganglionic sympathetic splanchnic nerves

Front 55

what are tumors of the adrenal medulla called

Back 55

pheochromocytomas

Front 56

what is considered the third eye in lower vertebrates

Back 56

pineal gland

Front 57

what is the pineal gland sensitive to

Back 57

light

Front 58

what is the pineal gland covered by

Back 58

tissue of the pia mater

Front 59

what are the primary cellular components of the pineal gland

Back 59

astrocytes
pinealocytes

Front 60

what does the pineal gland in response to light? dark?

Back 60

light: serotonin
dark: melatonin

Front 61

what happens to the melatonin released by the pineal gland

Back 61

it is released into the interstitial space to be taken up by the capillaries and distributed via the blood

Front 62

what happens to the seratonin released by the pineal gland

Back 62

taken up by the presynaptic axon terminals

Front 63

what controls secretion of melatonin in the pineal gland

Back 63

norepinephrine released by the postganglionic sympathetic nerves at the pinealocytes

Front 64

what are the supporting cells of the pineal gland

Back 64

astrocyte-like neuroglial cells

Front 65

is the pineal gland known for having occasional unusual structures

Back 65

yes, like skeletal m

Front 66

what is a definitive characteristic of the pineal gland

Back 66

concentric rings of calcium phosphates and carbonates called "brain sand," corpora arenacea or psammoma bodies

Front 67

what are the 7 main parts of the endocrine system

Back 67

hypothalamus
pituitary gland
adrenal gland
pineal gland
pancreas (endo part)
thyroid gland
parathyroid gland

Front 68

where are islets of langerhans located

Back 68

in the endo part of the pancreas

Front 69

what are the 5 types of cells in the islets of langerhans

Back 69

alpha
beta
delta
gamma

Front 70

what do beta cells of the pancreas secrete

Back 70

insulin

Front 71

what cells in the islets of langerhan comprise about 75% of the total cells

Back 71

beta cells

Front 72

where does insulin come from

Back 72

synthesized as a pre-proinsulin on the RER of beta-cells
formed into proinsulin and activated within the golgi apparatus
then C chain is cleaved away from the A and B chains to form insulin

Front 73

approximately how big is insulin and how many aa's

Back 73

MW 6000 Da
51aa

Front 74

what happens when there is a loss of beta-cells function and therefore decreased insulin

Back 74

diabetes mellitus

Front 75

what do the alpha cells of the pancreas secrete and in response to what

Back 75

glucagon
in response to low glucose levels

Front 76

what color do alpha and beta cells of the pancreas stain
and with what stain

Back 76

alpha: pink
beta: purple
gomori's stain

Front 77

approximately how big is glucagon and how many aa's

Back 77

MW 3500
29 aa's

Front 78

what do the delta cells secrete

Back 78

somatostatin

Front 79

what does somatostatin do to alpha and beta cells within the islets of langerhan in the pancreas

Back 79

inhibits them

Front 80

approximately how big is somatostatin and how many aa's

Back 80

MW 2000 Da
14aa

Front 81

what do PP-cells secrete in the pancreas and what does PP stand for

Back 81

pancreatic polypeptide
secrete panreatic polypeptides

Front 82

what do G cells of the pancreas secrete

Back 82

gastrin

Front 83

what is hyperplasia and what does it lead to

Back 83

over-production of gastrin
leads to zollinger-ellison syndrome leading to duodenal ulcers and pernicious anemia

Front 84

where does the parathyroid gland come from embryologically

Back 84

arises out of the floor of the buccal cavity
two lobes are eventually located lateral to the trachea in the region of the larynx

Front 85

what does the capsule of the parathyroid consist of

Back 85

dense irregular CT

Front 86

what is the septa of the parathyoird CT and what does the septa do

Back 86

loose CT
supports the organ

Front 87

what are the two main thyroid cell types

Back 87

follicular and parafollicular cells

Front 88

what is in the center of the follicles of the thyroid gland

Back 88

a gel-like material called colloid, the storage form of the follicular epithelial secretions

Front 89

what do parafollicular cells (C cells) secrete

Back 89

calcitonin, regulates calcium and phosphorous metabolism

Front 90

what will be present in the colloid of the thyroid gland follicle only if it is active

Back 90

colloid droplets adjacent to the luminal surface

Front 91

what is the protein component that binds the thyroid hormones

Back 91

thyroglobulin

Front 92

what is the basic function of the thyroid gland

Back 92

to regulate metabolism

Front 93

what does the thyroid gland secrete

Back 93

functional hormones: T3 (triiodthyroinine) and T4 (thyroxin or tetraiodothyronine)

Front 94

what do the thyroid hormones (T3 and T4) attache to and how are they released

Back 94

bound to thyroglobulin that must move back into the cell and be digested before releasing T3 and T4

Front 95

what regulates the thyroid secretions

Back 95

hypothalamus

Front 96

what is more common in cats, hyperthyroidism or hypothyroidism

Back 96

hyperthyroidism

Front 97

when do you see hypothyroidism

Back 97

when the thyroid is unable to respond to TSH, which may lead to thyroid enlargement (goiter)

Front 98

where do parathyroid glands originate from

Back 98

paired glands that derived from the third (external) and fourth (internal) pharyngeal pouches
Positioned on either side of the thyroid gland lobes

Front 99

what type of glands are the parathyroid glands

Back 99

cord-type endocrine glands

Front 100

what kind of CT makes up the parathyroid capsule

Back 100

dense irregular CT

Front 101

what are the primary cells of the parathyroid

Back 101

chief cells

Front 102

what do chief cells secrete of the parathyroid secrete and what does this secretion do

Back 102

PTH (parathyroid hormone) which regulates calcium

Front 103

what are the two parts of the calcium-phosphorus regulation mechanism

Back 103

parafollicular cells (C-cells) in the thyroid gland secrete calcitonin
Chief cells in the parathyroid gland secrete PTH

Front 104

are dark chief cells of the parathyroid active or inactive? what about the light cells

Back 104

dark: active
light: inactive

Front 105

what species has oxyphil cells of the parathyroid

Back 105

cattle, horses, humans