Topic 18: Endocrine System - Thyroid and Parathyroid Gland Flashcards
1
Q
Where is the thyroid gland? (2)
A
- on anterior surface of the superior part of the trachea
- butterfly shaped
2
Q
What is does the thyroid gland contain? (2)
A
- follicles
- Parafollicular cells
3
Q
What are the follicles in the thyroid gland made of?
A
- walls are made of epithelial cells (follicle cells)
4
Q
What do the follicles in the thyroid gland produce?
A
- T4
5
Q
Where are the parafollicular cells of the thyroid gland?
A
- between follicles
6
Q
What do the parafollicular cells secrete?
A
- calcitonin
7
Q
What is the function of calcitonin? (2)
A
- increase calcium uptake into bone (bone formation)
- thus lowering calcium in blood
8
Q
What are parathyroid glands?
A
- 4 (usually) glands embedded in posterior thyroid
9
Q
What do parathyroid glands secrete? What does it do?
A
- parathyroid hormone (PTH)
- increases blood calcium levels
10
Q
How does PTH increase calcium levels in blood? (5)
A
- increases Calcium release from bone (bone resorption)
- activates osteoclasts - Decrease calcium loss in urine (kidney)
- increase Vitamin D activation (kidney)
- vitamin D increases calcium absorption at small intestine