Flashcards in Lecture 18- Endocrine System Deck (61)
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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
