2024 CPPS 303 - Thyroid Function New Full Questions and Answers ( Included ) 100% Correct
- What is the thyroid gland?
Answer: a large ductless gland in the neck that secretes hormones regulating growth and development through the rate of metabolism.
- Where is the thyroid gland located?
Answer: Anterior surface of the trachea, composed of left and right lobes and a small connecting branch or isthmus
- Does the size of the gland depend on factors?
Answer: Yes, hereditary, environment and nutritional factors but on average it is between 20-34g
- What are the two distinct cell types that make up the thyroid gland?
Answer: Follicular cells
Parafollicular cells or C-cells that release calcitonin
- Is the thyroid gland easily palpable?
Answer: Yes due to its location, it can be felt with fingers when something goes wrong
- What is required for the thyroid hormones to become activated?
Answer: Thyroid hormones are the only ones that require iodine as essential trace element for the production of active forms of the hormones
- Hormone supplies for up to are stored?
Answer: 3 months
- Although thyroid hormones are peptides, their receptors are in the?
Answer: nucleusm and not on the cell membrane as the other peptide hormones
- Thyroid hormones have similar mechanism of action as steroids, and thus bind to
?
Answer: nuclear receptors
- Thyroid hormones are synthesized by the of the thyroid
gland? 1 / 2
Answer: follicular epithelial cells
- The follicular lumen is filled with
Answer: glycoprotein mixture known as colloid
- Synthesis of thyroid hormones is partly and partly ?
Answer: intracellular; extracellular
- Thyroid hormnones are made by
Answer: Iodinating tyrosine residues on thyroglobulin and are stored as part of
thyroglobulin molecules in thyroid follicules
- What are the 8 steps of of thyroid synthesis, storage and release?
Answer:
- Synthesis of thyroglobulin (TG)
- Iodide trapping
- Oxidation of Iodide
- Iodination of thyrosine
- Coupling reaction
- Endocytosis of thyroglobulin
- Hydrolysis of T3 and T4 from thyroglobulin
- Deiodination
- Where does stage 1, synthesis of thyroglobulin occur in?
Answer: thyroid follicular cell
- What is stage 1 of the synthesis of thyroid hormone?
Answer: Synthesis of thyroglobulin: Glycoprotein rich in tyrosine is synthesized in the rough endoplasmic reticulunm, modified in the Golgi body and packaged into secretory vesicles for exocytotic release into the lumen.
- What is stage 2 of the synthesis of thyroid hormone?
- / 2
Answer: Iodide trapping, sodium iodide co-transporter or symporter : Na/I symporter or cotransporter is located at the basolateral membrane fueld by the energy of the Na electrochenical gradient.The thyroid-stimulating hormone enhances Na/I symporter activity and thus iodide trapping. Elevated iodide levels inhibit the pump