Thyroid

TSH

thyroid stimulating hormone

thyrotoxicosis

thyroid storm

T4

thyroxine

Normally how many parathyroid glands are found in the neck?

4

What are the three strap muscles?

-omohyoid -sternothyroid -sternohyoid

Arterial Supply of thyroid:

-superior thyroid artery - 1st branch of ECA supplies blood to thyroid

Discuss the parathyroid glands?

-typically not seen on ultrasound due to small size -5 X 3 X 1 mm

Medullary Carcinoma

Associated with MEN 5% of thyroid carcinoma Secretes calcitonin

Anaplastic Carcinoma

Associated with elderly women Causes rapidly growing mass to obstruct airway 1% of thyroid cancer Aggressive Treatment resistance Death within 1 year

Which vascular structure lies closest to the thyroid lobes?

ICA

What structure connects the right and left lobe of the thyroid?

Isthmus

Which vascular structure lies most lateral to the thyroid lobes?

Jugular Vein

This structure consist of a combination of the recurrent laryngeal nerve and the inferior thyroid artery.

Minor Neurovascular Bundle

Opthalmopathy

Prominent eyes (bulging eyes)

This structure rises superiorly off of the isthmus and is found in 30% of the population as a normal variant.

Pyramidal Lobe

Discuss the location of the sternocleido mastiod.

Sits anterior lateral to the thyroid.

What muscles are located anterior to the thyroid gland?

Strap Muscles

What are the hormones produced by the thyroid?

Thyroxin, Tridothyronin, and Calcitonin

This structure is located immediately posterior to the isthmus and medial to the right and left lobes of the thyroid

Trachea

Which muscles are located lateral to each thyroid lobe?

anteriolaterally--sternocleidomastiod muscles

Parathyroids control the release and absorption of which nutrients?

blood calcium (calcitonin)

What type of gland is the thyroid?

endocrine--it's the largest gland because it works injunction with the hypothalamus and pituitary

This muscle is located anterolateral to the spine and posterior to the trachea. Sometimes mistaken for the trachea. Swallowing helps.

Longus Colli Muscle

Describe where the strap muscles are located.

They are the thin sonolucent bands along the anterior surface of the thyroid.

Benign congenital cysts located superior to the thyroid gland near the hyoid bone are referred to as:

Thyroglassal Duct Cyst (Cystic Midline Mass)

Which muscle is located posterior to each thyroid lobe?

Longus Colli Muscle

Thyroid Embryonal Development

-Arises from the median entodermal diverticulum during the 3rd week of embryologic development at the ventral wall of the pharynx -8th week of development follicles begin to form -Colloid tissue develops during 3rd month of gestation

Discuss Hashimoto's Disease

-Chronic inflammation of the thyroid gland caused by the formation of antibodies against normal thyroid tissue (autoimmune thyroid disease) -painless -diffuse enlargement of the thyroid in young or middle aged women -common cause of hypothyroidism -Increased Vascularity

Which of the following would most likely be a malignant nodule when doing a nuc med scan?

-Cold nodule means malignant -Hot nodule means benign

Lab findings with hypothyroidism:

-Decreased T3 -Decreased T4 -Increased TSH

Lab findings for hyperthyroidism:

-Increased T3 -Increased T4 -Decreased TSH

Graves disease

-an autoimmune disorder that is caused by hyperthyroidism and is characterized by goiter and/or exophthalmos -hallmark is opthalmopathy -thyroid storm (thyroid is burning up!)

characteristics of benign tumors of the thyroid:

-anechoic mass -complete halo -solitary

What is the most common cause of hypothyroidism?

-low iodine is the cause -Hashimoto's thyroiditis disease is most common disease

List the characteristics of malignant tumors of the thyroid:

-microcalcifications -solid hypoechogenicity -irregular mass -partial halo -more tall than wide

The normal length measurements for the thyroid range between:

4-6 cm in length

What structure may be confused for a thyroid or parathyroid mass because of its relationship to the trachea and the posterior aspect of the left thyroid gland?

Esophagus

What is the most common cause of hyperthyroidism?

Graves disease

A thyroid isthmus should measure?

Less than 4-5 mm

A bean shape seen in an area outside of the thyroid would be?

lymph node

Calcitonin

maintains homeostasis of blood calcium

What is the function of the thyroid?

maintains normal body metabolism, growth, and developement by synthesis, storage, and secretion of thyroid hormones

What is the most common cause of thyroid cancer?

papillary carcinoma

Hypercalcemia is associated with:

parathyroid

TSH is produced by

pituitary gland

The thyroid receives blood supply from

superior thyroid artery

T3

triiodothyronine

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Discuss Graves' Disease

-Autoimmune disorder common in women 30-40 -Hyperthyroidism due to circulating antibodies -Thyroid stimulating immunogloblulins -Causes thyroid to grow -Increased thyroid production -Graves' is the most common cause of hyperthyrodism

A cystic mass noted at the mandibular angle is most likely a:

brachial Cleft Cyst