Highison Histo Endocrine

Question 1

(blank) is a substance (chemical messenger) released into either blood, lymph, or extracellular space which has a specific effect. In this sense, thought to be an extension of neural transmission

Answer 1

hormones

Question 2

What are the 3 categories of hormones?

Answer 2

Steroids
Peptide
Amino Acid derivatives

Question 3

What hormones are lipid soluble?

Answer 3

steroids and thyroid hormones

Question 4

How do steroids and thryoid hormones work?

Answer 4

they diffuse through cell membrane into intracellular receptors to alter gene transcription or bind to surface receptors and mediate a response

Question 5

How do protein and amino acid hormones work?

Answer 5

they are water soluble so cant cross membrane so they bind to surface receptors and act via second messengers such as cAMP cGMP Calcium and sodium

Question 6

How do most hormones travel in the blood and what happens to them there?

Answer 6

they are bound to plasma proteins which renders them inactive

Question 7

most hormones are in oversupply in the blood or in undersupply in the blood?

Answer 7

oversupply

Question 8

What are the four types of hormonal secretions and how do they work?

Answer 8

autocrine (works on self cell)
paracrine (works on neighboring cell)
endocrine (travels through blood to different tissue)
Synaptic (neurotransmitters)

Question 9

Does the pancreas have a portal system?

Does the kidney?

Answer 9

yes

yes

Question 10

What are the three cell types in the islet of langerhan, what do they secrete and where do you find them?

Answer 10

A-> biggest, found on periphery, makes glucagon
B->most abundent,found in center, makes insulin
D-> scattered about, makes somatostatin

Question 11

How does the acini get blood?

Answer 11

from the insuloacinar portals system and the acinar vascular system

Question 12

What are the three minor cells types found in pancreatic islets?

Answer 12

PP cell -> pancreatic polypeptide (stimulates gastric chief cells)
D1 cell-> VIP (like glucagon, stimulates pancreatic exocrine secretion)
EC cell-> Secretin, motilin,Substance P (stimulates HCO3, increases motility, neurotransmitter properties)

Question 13

What is the hypophysis and what does it do?

Answer 13

It is the pituitary gland and secretes 9 hormones

Question 14

The hypothalamus is divided into 2 symmetrical halves by the (blank). It is limited rostrally (towards the front) by the (blank) and caudally by the (blank) and laterally by the (blank). and dorsolaterally by the (blank)

Answer 14

third ventricle
optic chiasma
mamillary body
optic tracts
thalamus

Question 15

What is the origin of the adenohypophysis (anterior pituitary gland)?

Answer 15

oral ectoderm (rathke’s pouch)

Question 16

What are the three parts of the adenohypophysis?

Answer 16

1 pars tuberalis
2 pars distalis
3 pars intermedia

Question 17

What is the origin of the neurohypophysis (posterior lobe)?

Answer 17

neural ectoderm

Question 18

What are the 2 parts of the neurohypophysis?

Answer 18

1) infundibulum

2) par nervosa

Question 19

Posterior part of the pituitary gland grows down from the brain. The first part of it is called (blank) and the bottom part is the (blank).

Answer 19

infundibilium

pars nervosa

Question 20

Adenohypophysis is derived from oral ectoderm made up of 3 parts the first part is the (blank), the (blank) is the meat of the anterior pituitary and then the (blank) separates the anterior from the posterior lobe.

Answer 20

pars tuberalis
pars distals
pars intermedia

Question 21

Describe the makeup of the adenohypophysis?

Answer 21

epithelial cells surrounded by extensive sinusoids

Question 22

What are the four cell types identified in the adenohypophysis by histology stains?

Answer 22

acidophils
basophils
chromophobes
folliculostellate cell

Question 23

What are the acidophilic cells of the adenohypophysis?

Answer 23

GH (somatotrophin)

Prolactin (mammotrophin)

Question 24

What are the basophilic cells of the adenohypophysis?

Answer 24

FSH and LH (gonadotrophins)
TSH (thyrotroph)
ACTH (corticotroph)
MSH (by product)

Question 25

What are the chromophobic cells of the adenohypophysis?

Answer 25

degranulated acidophils and basophils

Question 26

What are the folliculostellate cells of the adenohypophysis?

Answer 26

cellular stroma

Question 27

You can see five cells by immunocytochemistry in the adenohypophysis, what are they?

Answer 27

acidophils: somatotrophs, mammotrophs basophils: corticotrophs, thyrotrophs, gonadotrophs

Question 28

How does the adenohypophysis get blood?

Answer 28

Via hypothalamohypophysial portal system there is no direct blood supply to the adenohypophysis so instead it gets it indirectly via a hypophyseal portal vein that joins the primary capillary network in the infundibulum to the secondary capillary network in the pars distalis.

Question 29

What is the significance of a portal system?

Answer 29

to slow things down to allow us to put things into it.

Question 30

They hypophyseal portal system carriers (blank) from the hypothalamus to the pars distalis.

Answer 30

releasing factors

Question 31

(blank) is not an endocrine gland but rather a storage site.

Answer 31

neurohypophysis

Question 32

What is the neurohypophysis made up of?

Answer 32

unmyelinated axons and nerve endings of hypothalamic neurosecretory neurons

Question 33

What is the neurohypophysis supported by?

Answer 33

pituicytes (glial-like cells)

Question 34

What are pituicytes (glial-like cells) thought to do?

Answer 34

help in release of oxytocin and vasopressin into the perivascular space

Question 35

In the neurohypophysis, there are swellings at distal ends of hypothalamohypophysial axons called (blank)

Answer 35

herring bodies

Question 36

What are herring bodies?

Answer 36

site for storage of oxytocin and vasopressin

Question 37

Where is oxytocin synthesized? | Where is ADH (vasopressin) synthesized?

Answer 37

paraventricular nucleus | supraoptic nucleus

Question 38

How is ADH and oxtocin sent to the neurohypophyosis?

Answer 38

via the hypothalamoneurohypophysial tract with the carrier protein neurophysin. Hormones then enter pituitary through fenestrated capillaries derived from inferior hypophysial artery.

Question 39

What is right above the optic chiasm?

Answer 39

the supraoptic nucleus

Question 40

(blank) are synthesized in the hypothalamus as a hormone-neurphysin complex. This complex is then transported via the hypothalamohypophysial tract to the pars nervosa

Answer 40

2 hormones and neurophysin (protein carrier)

Question 41

What does oxytocin do?

Answer 41

induces labor, controls pospartum bleeding, acts on myoepithelial cells for milk letdown reflex

Question 42

(blank) occurs in the hypothalamic nuclei

Answer 42

crossover

Question 43

What is the first endocrine gland to appear in embryonic development?

Answer 43

thyroid

Question 44

What does the thyroid gland produce?

Answer 44

T3 and T4

Question 45

What is the structure of the thyroid?

Answer 45

encapsulated/ connective tissue extending in to form lobules, structural unit= follicles, follicles lined with an epithelium surrounding a colloid lumen enclosed by a basal lamina

Question 46

What are the 2 cell types in the thryoid gland?

Answer 46

follicular cells | parafollicular cells

Question 47

Where is the origin of follicular cells and what do they do?

Answer 47

endoderm, target cells for TSH and produce thryoglobulin and T3/T4

Question 48

Where is the origin of parafollicular cells (C cells) and what do they do?

Answer 48

neural crest, produce calcitonin and target osteoclasts to decrease caclium level (rapid effect, peak at an hour)

Question 49

Follicular cell height depends upon (blank)

Answer 49

activity

Question 50

What do follicular cells do?

Answer 50

synthesize thryoglobulin trap iodide extracellular iodination of thyroglobulin storage of iodinated thyroglobulin uptake of thryoglobulin (controlled by TSH) hydrolysis of 12 thyroglobulin to T3 and T4 (regulates tissue metabolism) T3 and T4 cross placenta and are critical in early brain development

Question 51

What are the three phases of thyroid cells?

Answer 51

thyroglobulin synthesis resting (storage phase) thyroglobulin breakdown

Question 52

Where are parafolicular cells (c cells) located?

Answer 52

in clusters between follicles

Question 53

What is the embryonic origin of parafollicular cells and what are they a part of?

Answer 53

neural crest | diffuse neuro-endocrine syste, (DNES)

Question 54

Do parafollicular cells extend into the lumen?

Answer 54

no

Question 55

What all do parafollicular cells do?

Answer 55

decrease calcium targets osteoclasts and reduces numbers and breakdown promotes excretion of Calcium and phosphate from kidneys

Question 56

What is the embryonic origin of parathyroid gland? What are the 2 main cells of the parathyroid gland?

Answer 56

mesoderm | principal (chief cells) and oxyphil cells

Question 57

What doe prinicipal cells do?

Answer 57

secrete PTH which increase calcium levels, binds to osteoblasts which stimulats osteoclast resorption, they are pale and small cells with slow long term effects that peak in several hours

Question 58

What are oxyphil cells?

Answer 58

larger than principal cells, possess lots of mitochondrias, appears at puberty and increases with age and the function is unknown

Question 59

The precursor of the osteoclast originates in the (blank)

Answer 59

bone marrow

Question 60

(blank) have a number of receptors for various hormones including calcitonin. These cells are responsible for resorbing bone.

Answer 60

osteoclast

Question 61

(blank) are large, motile, multinucleated cells and contain up to 50 nuclei and have an acidophilic cytoplasm. The have a bone marrow precursor in common with monocytes.

Answer 61

osteoclasts

Question 62

Osteoclasts occupy shallow depressions called (blank) that identify regions of bone resorption.

Answer 62

howship's lacunae

Question 63

What does PTH target?

Answer 63

it targets osteoblast NOT osteoclasts

Question 64

Bone is (blank)

Answer 64

dynamic

Question 65

When PTH targets osteoblast, this stimulates osteoclasts to release (blank) and (blank) into the space between the osteoclasts and the bone. The hydrogen ions acidify this space and allows for the resorption of (blank and blank) and activates the (blank). This allows the bone matrix to get broken down and the products are absorbed into the osteoclast.

Answer 65

Lysosomal enzymes and hydrogen ion phosphate and calcium lysosomal hydrolases

Question 66

When the osteoclasts releases release lysosomal enzymes, one vital lysosome is present in the bone matrix but not secreted by the osteoclasts, so where do they come from?

Answer 66

It was put in there by osteoblasts!!!!! which means while the osteoblasts were building the bone they were preparing for the bone to be broken down. Shows dynamic nature of bone.

Question 67

Calcitonin that is secreted by (blank) cells of the thyroid suppresses bone resorption by osteoclasts thereby decreasing calcium levels.

Answer 67

parafollicular cells

Question 68

The medulla of adrenal gland is made from (blank) and these cells travel so what can be the clinical significance of this?

Answer 68

neural crest cells | We can find medulla tissue sometimes in the circulation

Question 69

Is the adrenal gland encapsulated?

Answer 69

yes

Question 70

What are the 2 parts of the adrenal gland?

Answer 70

cortex and medulla

Question 71

What is the adrenal cortex derived from, what steroid hormones do they produce?

Answer 71

mesoderm | From LDL cholesterol, they produce the steroid hormones, mineralcorticoids, glucocorticoids, androgens

Question 72

What controls the secretion of mineralcorticoids, glucocorticoids and androgens from the adrenal cortex?

Answer 72

ACTH and kidney

Question 73

What is the structure of the adrenal cortex?

Answer 73

columns (cords) of cells separated by sinusoids

Question 74

What is the adrenal medulla made from, what does it produce and what is its structure?

Answer 74

derived from neural crest cells produced catecholamines (epi and norepi) large vascular sinusoids and blood vessels innervated by preganglionic sympathetic fibers

Question 75

How is the adrenal medulla innerved by preganglionic sympathetic fibers?

Answer 75

via splachnics that pass through the celiac plexus

Question 76

The adrenal cortex consists of three zones, what are they?

Answer 76

``` zona glomerulosa (aldosterone) zona fasciculata (cortisol) zona reticularis (sex hormones) ```

Question 77

Tell me what the zona glomerulose secretes, what regulates it, and does it regenerate?

Answer 77

mineralcorticoids (mostly aldosterone) regulated by RAAS and ACTH Is the only regenerative zone of adrenal cortex

Question 78

What is the structure of the zona fasciculata (ZF)?

Answer 78

thick middle zone with large lipid containing cells which form parallel cords of cells separated by sinusoids

Question 79

What does the zona fasciculata secrete and what is it controlled by?

Answer 79

secretes glucocorticoids ( mainly corticosterone and cortisol) controlled by ACTH

Question 80

What is the structure of the zona reticularis (ZR)?

Answer 80

the innermost layer that contains lipofuscin granules.

Question 81

What does the zona reticularis secrete and what is it controlled by?

Answer 81

androgenic steroids and controlled by ACTH

Question 82

What can we consider the zona reticularis?

Answer 82

as the graveyard containing residues of lysosomal digestion

Question 83

What does high levels of corticosterone and cortisol do?

Answer 83

shut down the zona fasciculata

Question 84

(blank) are innervated by preganglionic sympathetic nerve fibers and act like postganglioic sympathetic neurons.

Answer 84

chromaffin cells

Question 85

What suppresses the axons of chromaffin cells?

Answer 85

glucorticoids

Question 86

Chromaffin cells release 2 things, what percentage does it secrete each of these things, and what does each thing do?

Answer 86

80% epi-> increase HR and CO; no change in BP 20% norepi-> increase in BP through vasoconstriction AND stores some opoids

Question 87

What are the opoids that chromaffin cells store and what do they do?

Answer 87

enkephalins which have analgesic properties

Question 88

What is the blood supply to the adrenal cortex?

Answer 88

cortex-> from vascular bed of the capsular arteries and sinusoids which travel through cortex and drain into medulla

Question 89

What is the blood supply to the adrenal medulla?

Answer 89

from capsular arterioles and from cortical sinuosoids | duel blood supply required to make epi and inhibit axonal growth

Question 90

(blank) inhibit axonal growth in the chromaffin cells/

Answer 90

glucocorticoids

Question 91

What enter the medullary venous sinuses of the adrenal gland?

Answer 91

mineralcorticoids, cortisol, and sexual steorids

Question 92

The superior and middle adrenal arteries make up the (blank) which supplies the 3 zones of the cortex with fenestrated cortical capillaries.

Answer 92

capsular plexus

Question 93

What kind of capillaries are in the adrenal cortex?

Answer 93

fenestrated

Question 94

Where does the medullary artery come form and what does it do?

Answer 94

comes from inferior adrenal artery and supplies the adrenal medulla by bypassing the cortex WITHOUT branching.

Question 95

In the medulla, the medullary artery joins with the (blank) to form the medullary venous sinuses creating the dual blood supply to the medulla.

Answer 95

cortical capillaries

Question 96

What is the origin of the pineal gland?

Answer 96

neuroectoderm

Question 97

The pineal gland contains two cells types which are....?

Answer 97

pinealocytes (make melatonin at night and serotonin during the day) neuroglial cells

Question 98

Melatonin levels are (blank) in children (pre-puberty)

Answer 98

high

Question 99

Melatonin levels (balnk) with onset of puberty

Answer 99

decline

Question 100

The pineal gland consists of melatonin-secreting pinealocytes arranged in (blank) enclosed by processes derived from the (blank).

Answer 100

solid cords | glial like-interstitial cells

Question 101

A typical feature of the histology of the pineal gland is the presence of (blank) called corpora arenacea found in the extracellular space.

Answer 101

calcium deposits

Question 102

The nerve input to the pineal gland is from the (blank) derived from the superior cervical ganglion.

Answer 102

postganglionic sympathetic nerve fibers

Question 103

Meninges that envelop the pineal gland invade the developing gland forming a (blank)

Answer 103

connective tissue septa

Question 104

What is helpful about the pineal gland clinically?

Answer 104

can be used as a radiological landmark

Question 105

What are the calcium deposits in the pineal gland called?

Answer 105

corpora arenacea