Anatomy
What are the names of the arteries that supply the thyroid in the majority of the population?
What to parafollicular cells secrete?
Calcitonin.
What is the embryological origin of the follicular cells?
A) Ectoderm
B) Mesoderm
C) Endoderm
C) Endoderm
Name two possible symptoms of a general hyperthyroid patient.
Weight loss
Sweating
Palpitations/ arrythmias
Anxiety
Heat intolerance
Pretibial myxoedema
Hyperreflexia
Tachycardia
What is the origin of the inferior thyroid artery?
thyrocervical trunk, the 2nd branch of the subclavian artery.
What is the hormone responsible for stimulating the anterior pituitary to release thyroid-stimulating hormone?
thyrotropin-releasing hormone (TRH)
What is the origin of the thyroid ima artery?
Brachiocephalic trunk
What is a defining clinical sign of Grave's disease?
exophthalmos (bulging of the eyes)
What two vessels are located posterior to the neck of the pancreas?
Superior mesenteric artery and vein.
Which cells do calcitonin interact with to increase the availability of calcium?
Osteoclasts.
Which form of thyroiditis is marked by high levels of fibrosis on histology?
Reidle's thyroiditis
Name three histological changes you would see on someone's thyroid who has Grave's disease.
Hyperplastic epithelium with infolding
Columnar follicular cells
Scalloping of the colloid
A patient comes into the clinic with a very monotone voice and is unable to change pitch. They also have a painfully enlarged anterolateral neck. What structure is most likely affected resulting in this presentation?
Thyroid peroxidase (TPO)
A patient presents with a hip fracture, is in a state of psychosis, and has multiple kidney stones. The ED doctor suspects a specific disease and does a skull X-ray which reveals a salt and pepper-like appearance. What disease process is most likely occuring?
Hyperparathyroidism, resulting in hypercalcemia.
What two cancers can cause hyperthyroidism due to paraneoplastic syndrome?
Small cell lung cancer
Struma ovarii (ovarian teretoma with thyroid tissue).
What is the embryological origin of the thyroid? (structure not tri-laminar disc layer).
First pharyngeal arch
What is thyroid hormone mostly bound to in blood
Thyroxin-binding globulin (TBG)
A patient after experiencing obstructive symptoms of goiter undergoes fine-needle aspiration of the thyroid and coffee bean cells are seen on cytology, what is the diagnosis and definitive first line of treatment recommendation for this patient? What system can be used to make this decision?
Treatment: thyroidectomy
The Bethesda system is used to triage potential thyroid cancer.
What is the mechanism of action of Carbimazole?
Prevents TPO (thyroid peroxidase) from oxidizing iodide to iodine which stops the coupling of tyrosine residues on thyroglobulin. Ultimately decreasing T4 production.