Lecture 18- Endocrine System Flashcards Preview

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Flashcards in Lecture 18- Endocrine System Deck (61):
1

What do all endocrine glands have in common (or what defines an endocrine gland?

They secrete hormones into the blood

2

What is paracrine secretion?

Hormone to a target cell

3

What is autocrine secretion?

Hormone to self

4

What makes up the posterior pituitary gland?

- infundibulum or pituitary stalk
- pars nervosa
- tissue develops from brain

5

What makes up the anterior pituitary gland?

- pars tuberalis
- pars intermedia
- pars distalis
- tissue derived from ectoderm

6

What are sinusoids?

Essentially giant capillaries

7

What are degranulated cells?

Cells that turn back into an acidophil or basophil

8

What are progenitor cells?

Cells that go on to produce other cell types

9

What are chromophobes?

Either degranulated cells or progenitor cells

10

What are the acidophils?

- somatotropes (growth hormone)
- mammotropes (prolactin)

11

What are the basophils?

- gonadotropes (FSH and LH)
- thyrotropes (TSH)
- corticotropes (POMC) cleaves to (ACTH)

12

What is the best way to differentiate these cells?

- immunohistochemistry

13

The blood supply to the median eminence, infundibulum, and anterior pituitary is a portal system? What does that mean

Two capillary beds

14

What does the pars tuberalis secrete?

mainly basophilic gonadotropes

15

What does the pars intermedia secrete?

basophilic cortico tropes. POMC cleaved to melanocyte stimulating hormone. In pars distalis POMC cleaved to ACTH

16

What does oxytocin do?

- milk let down
- uterine contraction during labor

17

What are pituicytes?

Glial cells that surround the unmyelinated axons

18

What are herring bodies?

Cells that store the hormone

19

Where are the neuronal cell bodies for the posterior pituitary?

hypothalamus

20

Where are the alpha cells located in the islets of langerhans?

Along the periphery- glucagon- raises blood glucose

21

Where are the beta cells located in the islets of langerhans?

On the interior- insulin that lowers blood glucose

22

Where is the adrenal gland found?

On top of the kidney, suprarenal gland

23

What are the three layers of the adrenal gland?

- capsule
- cortex derived from mesoderm
- medulla derived from neural crest

24

What are the three layers of the cortex?

- zona glomerulosa
- zona fasciculata
- zona reticularis

25

They precursor to hormones produced in the adrenal cortex is cholesterol. What does this tell you?

Lipid soluble, hydrophobic

26

What is secreted in the zona glomerulosa?

aldosterone

27

What are mineralocorticoid and give an example.

aldosterone, influence salt and water balance

28

What does aldosterone do?

Released from the adrenal gland under low BP to stimulate Na+ retention and for the kidney to release renin and angiotensin II

29

What effect does aldosterone have on blood K+ levels?

increases secretion of K+ in the collecting duct to lower blood K+

30

What does the zona fasciuluta release?

glucocorticoids (eg cortisol), washed out lipid droplets that contained steroids

31

What signals the release of cortisol?

ACTH

32

What effect does cortisol have on the hypothalamus?

negative feedback

33

What effects does cortisol have on the body?

- immunosuppressive
- anti- inflammatory

34

What is released in the zona reticularis?

androgens- lipid soluble steroids, wide capillaries or sinusoids

35

What induces the release of androgens from the adrenal gland?

ACTH

36

Where are chromaffin cells?

adrenal medulla, derived from the neural crest

37

What effect does the sympathetic pre-ganglionic neuron have on the adrenal medulla?

release epinephrine

38

If the sympathetic pre-ganglionic synapses on a post ganglionic neuron, what will be secreted?

norepinephrine

39

What are the main parts of the thyroid?

- capsule
- septa
- thyroid follicles

40

What are the follicular cells?

Simple epithelium, cuboidal or columnar

41

What is the colloid filled lumen?

thyroglobulin

42

What is stored in the C cells?

Calcitonin

43

If the follicular cells are inactive (No TSH) they are more?

squamous

44

If the follicular cells are active, they are...

more cuboidal or columnar, thyroid hormone

45

What are three effects of thyroid hormone?

- increase basal metabolic rate
- increase lipid metabolism
- increase in carbohydrate metabolism

46

Which cell has secretory granules?

C cells

47

What effect does the caclitonin from the secretory granules have on the body?

inhibit osteoclasts

48

What does thyroglobulin help store?

Iodine in T3 and T4

49

What stimulates the production and release of thyroid hormone from the thyroid gland?

TSH from anterior pituitary

50

What shuts off TSH release from the pituitary?

Thyroid Stimulating Hormone

51

What shuts off TSH release from the pituitary?

Thyroid Hormone, negative feedback

52

What would the cells look like if a test revealed elevated serum TSH levels?

Follicular cell hyperplasia but with little colloid

53

What cells are found in the parathyroid gland?

- chief cells
- oxyphil cells

54

What do chief cells secrete?

Parathyroid hormone, purple nuclei with pale but acidophilic cytoplasm

55

Low blood calcium levels stimulate parathyroid hormone secretion. How does PTH raise blood Ca++ levels?

Increases Ca++ reabsorption in the kidney tubule

56

What does PTH do in the kidney?

increases the synthesis of 1-ahydroxylage in the PCT of the kidney. Activates Vitamin D to enable Ca++ absorption from the gut

57

What does the pineal gland secrete?

melatonin

58

What does melatonin do?

regulates circadian rhythm, darkness promotes the release of melatonin

59

What is a corpora arenacea?

brain sand, Ca, Mg salts.

60

What are the other cells found in the pineal gland?

- pinealocytes
- astrocytes
- corpora arenacea
- septa

61

Some groups recommend stopping fluoride treatment because they could possibly contribute to the calcification of what structure?

pineal gland