Lecture 23 Micro anatomy Endocrine System Flashcards
What do hormones do?
Cause a change in the metabolic activity in target tissues
Hypothalamus function (pituitary)
Provides a neural link to the endocrine system via the hypophyseal portal system
Location of the pituitary
The hypophyseal fossa of the sphenoid bone
Cells of the anterior pituitary and what they produce
Gonadotrophs- LH and FSH - stimulate gonad production
Corticotrophs - release adrenocorticotrophic hormone ACTH
Thyrotrophs- release TSH
Somatotrophs- growth hormone release
Mammotrophs- prolactin- breast milk production
Structure of the posterior pituitary (MAY NEED UPDATING)
Cell bodies coming from the paraventricular and supraoptic regions produce hormone and send it to the unmyelanated axons in the posterior pituitary
What hormone does the paraventricular nuclei produce?
Oxytocin, stored in the herring bodies in the posterior pituitary
What hormone does the supraoptic nuclei produce?
ADH, stored in the herring bodies of the posterior pituitary
What cell stores the hormone in the posterior pituitary
Herring bodies
What are the functional units of the thyroid and parathyroid
Follicular cells
C cells in the parathyroid
What hormone is produced by the parathyroid which lowers blood calcium levels?
Calcitonin
- ↑ osteoblasts bone formation
- in abscence of activated vitamin D
What do follicular cells of the thyroid produce?
T3 and T4
What is the effects of thyroid hormone in the body?
↑ metabolic activity
↑ heat production
↑ growth and development
↑ catecholamine effects
What is thyroglobulin
Protein in the thyroid follicular cells, from which T3 and T4 are synthesised
Conversion of T4 to T3 occurs
In the peripheral tissue
T3 is more active than T4
Effect of TSH on the thyroid
Thyroid stimulating hormone causes the release of protein bound T3 and T4, with release into the blood stream
