Lecture 18- Endocrine System Flashcards Preview

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Flashcards in Lecture 18- Endocrine System Deck (61)
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1
Q
What do all endocrine glands have in common (or what defines an endocrine gland?
A
They secrete hormones into the blood
2
Q
What is paracrine secretion?
A
Hormone to a target cell
3
Q
What is autocrine secretion?
A
Hormone to self
4
Q
What makes up the posterior pituitary gland?
A
- infundibulum or pituitary stalk
- pars nervosa
- tissue develops from brain
5
Q
What makes up the anterior pituitary gland?
A
- pars tuberalis
- pars intermedia
- pars distalis
- tissue derived from ectoderm
6
Q
What are sinusoids?
A
Essentially giant capillaries
7
Q
What are degranulated cells?
A
Cells that turn back into an acidophil or basophil
8
Q
What are progenitor cells?
A
Cells that go on to produce other cell types
9
Q
What are chromophobes?
A
Either degranulated cells or progenitor cells
10
Q
What are the acidophils?
A
- somatotropes (growth hormone)
- mammotropes (prolactin)
11
Q
What are the basophils?
A
- gonadotropes (FSH and LH)
- thyrotropes (TSH)
- corticotropes (POMC) cleaves to (ACTH)
12
Q
What is the best way to differentiate these cells?
A
- immunohistochemistry
13
Q
The blood supply to the median eminence, infundibulum, and anterior pituitary is a portal system? What does that mean
A
Two capillary beds
14
Q
What does the pars tuberalis secrete?
A
mainly basophilic gonadotropes
15
Q
What does the pars intermedia secrete?
A
basophilic cortico tropes. POMC cleaved to melanocyte stimulating hormone. In pars distalis POMC cleaved to ACTH
16
Q
What does oxytocin do?
A
- milk let down
- uterine contraction during labor
17
Q
What are pituicytes?
A
Glial cells that surround the unmyelinated axons
18
Q
What are herring bodies?
A
Cells that store the hormone
19
Q
Where are the neuronal cell bodies for the posterior pituitary?
A
hypothalamus
20
Q
Where are the alpha cells located in the islets of langerhans?
A
Along the periphery- glucagon- raises blood glucose
21
Q
Where are the beta cells located in the islets of langerhans?
A
On the interior- insulin that lowers blood glucose
22
Q
Where is the adrenal gland found?
A
On top of the kidney, suprarenal gland
23
Q
What are the three layers of the adrenal gland?
A
- capsule
- cortex derived from mesoderm
- medulla derived from neural crest
24
Q
What are the three layers of the cortex?
A
- zona glomerulosa
- zona fasciculata
- zona reticularis
25
Q
They precursor to hormones produced in the adrenal cortex is cholesterol. What does this tell you?
A
Lipid soluble, hydrophobic
26
Q
What is secreted in the zona glomerulosa?
A
aldosterone
27
Q
What are mineralocorticoid and give an example.
A
aldosterone, influence salt and water balance
28
Q
What does aldosterone do?
A
Released from the adrenal gland under low BP to stimulate Na+ retention and for the kidney to release renin and angiotensin II
29
Q
What effect does aldosterone have on blood K+ levels?
A
increases secretion of K+ in the collecting duct to lower blood K+
30
Q
What does the zona fasciuluta release?
A
glucocorticoids (eg cortisol), washed out lipid droplets that contained steroids
31
Q
What signals the release of cortisol?
A
ACTH
32
Q
What effect does cortisol have on the hypothalamus?
A
negative feedback
33
Q
What effects does cortisol have on the body?
A
- immunosuppressive
- anti- inflammatory
34
Q
What is released in the zona reticularis?
A
androgens- lipid soluble steroids, wide capillaries or sinusoids
35
Q
What induces the release of androgens from the adrenal gland?
A
ACTH
36
Q
Where are chromaffin cells?
A
adrenal medulla, derived from the neural crest
37
Q
What effect does the sympathetic pre-ganglionic neuron have on the adrenal medulla?
A
release epinephrine
38
Q
If the sympathetic pre-ganglionic synapses on a post ganglionic neuron, what will be secreted?
A
norepinephrine
39
Q
What are the main parts of the thyroid?
A
- capsule
- septa
- thyroid follicles
40
Q
What are the follicular cells?
A
Simple epithelium, cuboidal or columnar
41
Q
What is the colloid filled lumen?
A
thyroglobulin
42
Q
What is stored in the C cells?
A
Calcitonin
43
Q
If the follicular cells are inactive (No TSH) they are more?
A
squamous
44
Q
If the follicular cells are active, they are...
A
more cuboidal or columnar, thyroid hormone
45
Q
What are three effects of thyroid hormone?
A
- increase basal metabolic rate
- increase lipid metabolism
- increase in carbohydrate metabolism
46
Q
Which cell has secretory granules?
A
C cells
47
Q
What effect does the caclitonin from the secretory granules have on the body?
A
inhibit osteoclasts
48
Q
What does thyroglobulin help store?
A
Iodine in T3 and T4
49
Q
What stimulates the production and release of thyroid hormone from the thyroid gland?
A
TSH from anterior pituitary
50
Q
What shuts off TSH release from the pituitary?
A
Thyroid Stimulating Hormone
51
Q
What shuts off TSH release from the pituitary?
A
Thyroid Hormone, negative feedback
52
Q
What would the cells look like if a test revealed elevated serum TSH levels?
A
Follicular cell hyperplasia but with little colloid
53
Q
What cells are found in the parathyroid gland?
A
- chief cells
- oxyphil cells
54
Q
What do chief cells secrete?
A
Parathyroid hormone, purple nuclei with pale but acidophilic cytoplasm
55
Q
Low blood calcium levels stimulate parathyroid hormone secretion. How does PTH raise blood Ca++ levels?
A
Increases Ca++ reabsorption in the kidney tubule
56
Q
What does PTH do in the kidney?
A
increases the synthesis of 1-ahydroxylage in the PCT of the kidney. Activates Vitamin D to enable Ca++ absorption from the gut
57
Q
What does the pineal gland secrete?
A
melatonin
58
Q
What does melatonin do?
A
regulates circadian rhythm, darkness promotes the release of melatonin
59
Q
What is a corpora arenacea?
A
brain sand, Ca, Mg salts.
60
Q
What are the other cells found in the pineal gland?
A
- pinealocytes
- astrocytes
- corpora arenacea
- septa
61
Q
Some groups recommend stopping fluoride treatment because they could possibly contribute to the calcification of what structure?
A
pineal gland