Histology of Endocrine Glands Flashcards
What are the physical properties of exocrine glands?
- Maintain continuity with surface e[ithelium,
- Have polarized cells with polarized secretions
- Lots of RER
What are the physical properties of endocrine glands?
- Lose contact with surface epithelium
- Non-polarized cells with non-polarized secretion
- Little RER
NOTE: The thyroid gland is one exception to this rule
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Compare and contrast exocrine cell, peptide-secreting endocrine cells, and steriod- secreting endocrine cells.
Exocrine cell
- Secretion granules
- Golgi
- Nucleus
- Lots of RER
- basal lamina
Peptide-secreting endocrine cell
- Small secretions
- Capillaries
- Little RER
Steroid -secreting endocrine cell
- Stored lipid (non secretion granules_
- SER
- Capillaries
- Little RER
Location of the major endocrine glands of the body
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Thyroid Follicle
How do warmth and cold regulate TSH secretion?
- Cold acts on the hypothalamus stimulating the release of TRF.
- TRF stimulates the anterior pituatary to release TSH
- TSH stimulates the thyroid to release free T3 and T4, causing you to feel warmth
- T3 and T4 then send negative feeback signals to the anterior pituatary and the hypothalamus to inhibit release of those hormones
What causes the eye to protrude in patient’s with Grave’s disease?
Edema behind the eye
NOTE: Grave’s disease is characteristic of hypersecretion of thyroid hormones
Why is low iodine associated with goiters?
If you don’t get enough iodine the thyroid gland will continously make thyroglobulin and will secrete that into the extracellular space but it will never make the complet hormone because of the lack of iodine. When the gland gets larger you get a goiter.
How do you distinguish between parafollicular cells (C cells) and follicle cells?
- C cells are larger and more lightly stained than follicle cells.
- C cells don’t touch the lumen
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Function of Calcitonin
- Reduces level of blood calcium
- Inhibits oseoclastic activity
Where is the parathyroid gland located?
Dorsal to the thyroid gland
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