Podcast
Questions and Answers
Where is the thyroid gland located?
Where is the thyroid gland located?
- Lateral to the larynx and trachea
- Posterior to the larynx and trachea
- Medial to the larynx and trachea
- Anterior to the larynx and trachea (correct)
What is the function of thyroid hormone?
What is the function of thyroid hormone?
- To regulate metabolism, growth, and development (correct)
- To increase calcium levels in the blood
- To decrease bone resorption
- To lower blood pressure
What is the function of calcitonin hormone?
What is the function of calcitonin hormone?
- To increase calcium levels in the blood
- To decrease bone resorption (correct)
- To regulate metabolism, growth, and development
- To lower blood pressure
What is the stroma of the thyroid gland composed of?
What is the stroma of the thyroid gland composed of?
What is the composition of the thyroid parenchyma?
What is the composition of the thyroid parenchyma?
What is the function of follicular cells?
What is the function of follicular cells?
What type of cells are found inside the basal lamina of the follicular epithelium?
What type of cells are found inside the basal lamina of the follicular epithelium?
What is the approximate duration that the thyroid gland can supply the body with hormone without additional synthesis?
What is the approximate duration that the thyroid gland can supply the body with hormone without additional synthesis?
What is the shape of Chief cells in the Parathyroid gland?
What is the shape of Chief cells in the Parathyroid gland?
What is the function of Oxyphil cells in the Parathyroid gland?
What is the function of Oxyphil cells in the Parathyroid gland?
What is the characteristic of the cytoplasm of Oxyphil cells?
What is the characteristic of the cytoplasm of Oxyphil cells?
What happens to Chief cells with increasing age?
What happens to Chief cells with increasing age?
What is the major function of Parathyroid hormone (PTH)?
What is the major function of Parathyroid hormone (PTH)?
What is the primary function of the parathyroid glands?
What is the primary function of the parathyroid glands?
What is the characteristic of the nucleus of Chief cells?
What is the characteristic of the nucleus of Chief cells?
What triggers the secretion of calcitonin from parafollicular cells?
What triggers the secretion of calcitonin from parafollicular cells?
What is the main difference between the cytoplasm of Chief cells and Oxyphil cells?
What is the main difference between the cytoplasm of Chief cells and Oxyphil cells?
Which gland is responsible for secreting thyroid hormones?
Which gland is responsible for secreting thyroid hormones?
What is the function of parathyroid hormone (PTH) on bones?
What is the function of parathyroid hormone (PTH) on bones?
What is the role of PTH in kidney function?
What is the role of PTH in kidney function?
What is the result of PTH on phosphorus levels in the blood?
What is the result of PTH on phosphorus levels in the blood?
What is the structural component of the parathyroid gland that surrounds each gland?
What is the structural component of the parathyroid gland that surrounds each gland?
What is the function of calcitonin?
What is the function of calcitonin?
What is the location of the parathyroid glands?
What is the location of the parathyroid glands?
Study Notes
The Thyroid Gland
- Located in the front of the neck, anterior to the larynx and trachea
- Releases two hormones:
- Thyroid hormone (Thyroxin): regulates metabolism, growth, and development
- Calcitonin hormone: lowers calcium levels in the blood by decreasing bone resorption
- Histology:
- Stroma: double capsule, CT septa, and reticular fibers that form a network supporting the thyroid parenchyma
- Parenchyma: composed of millions of rounded epithelial structures called follicles
- Follicles: each consists of a simple epithelium and a central lumen filled with a gelatinous substance called colloid
- Colloid contains thyroglobulin, the precursor for active thyroid hormones
- Follicular cells (Principal cells): range in shape from squamous to low columnar
- Parafollicular cells (C cells): synthesize and secrete calcitonin, which suppresses bone resorption by osteoclasts
Feedback Mechanism
- Not explicitly mentioned in the text, but implied through the regulation of calcium levels
The Parathyroid Glands
- 4 small glands located behind the thyroid gland
- Regulate the body's calcium and phosphorus levels through the secretion of parathyroid hormone (PTH)
- Functions:
- Calcium regulation: releases PTH into the bloodstream when blood calcium levels drop below normal
- Bone maintenance: PTH acts on the bones to release calcium stored in bone tissue
- Kidney function: PTH acts on the kidneys to increase calcium reabsorption and convert vitamin D into Calcitriol
- Phosphorus regulation: PTH decreases phosphorus reabsorption in the kidneys, leading to increased excretion in the urine
- Histology:
- Stroma: thin capsule, CT septa, and network of reticular fibers that support the parenchyma cells
- Parenchyma: consists of cords of polygonal cells surrounded by a rich network of fenestrated blood capillaries
- Chief cells: secrete parathyroid hormone, have large nuclei, and pale cytoplasm with glycogen granules and lipid droplets
- Oxyphil cells: unknown function, few in number, with large polygonal shape, small and dense nucleus, and deep eosinophilic cytoplasm with many mitochondria
Comparison of Glands
- Thyroid gland: follicular cells secrete thyroid hormones, C cells secrete calcitonin
- Parathyroid glands: chief cells secrete parathyroid hormone
- Functions: thyroid hormones increase metabolic rate, calcitonin lowers blood Ca2+ levels, parathyroid hormone raises blood Ca2+ levels
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the structure and function of parafollicular cells and parathyroid glands in the endocrine system, including their role in regulating calcium levels.