thyroid gland part 1

where is the thyroid gland located?

in the lower, anterior portion of the neck and anterior to the trachea

in women, the thyroid gland is:

normally larger and becomes enlarged during pregnancy

normal measurements of the R+L lobes of the thyroid:

• 4-6 cm in L

• 1.5-2 cm in W

• 2 cm in H (AP)

normal measurement of the isthmus:

2-6 mm (AP)

where is a pyramidal lobe more commonly found?

on the L lobe of the thyroid and is found in 15-30% of pts

what muscles are located anterior to the thyroid?

the strap muscles and sternocleidomastoid

what muscles are known as the strap muscles?

• sternothyroid

• omohyoid

• sternohyoid

what structures are located posterolateral to the thyroid?

• common carotid artery

• internal jugular vein

• vagus nerve

what muscle is located posterolateral to the thyroid?

longus colli muscle

sonographic appearance of the longus colli muscle:

hypoechoic triangular structure adjacent to the cervical vertebrae

what structures are located medial to the thyroid?

• larynx

• trachea

• inferior constrictor of the pharynx

• esophagus

where is the esophagus located?

primarily midline but may be found to the left of the trachea

sonographic appearance of the esophagus:

• target appearance in transverse

• can be identified by its peristaltic movement when the pt swallows

the posterior border of each lobe of the thyroid is related to:

the superior and inferior parathyroid glands and anastomosis between the superior and inferior thyroid arteries

the thyroid gland is one of the largest:

endocrine glands

function of the thyroid gland:

maintains normal body metabolism growth development by synthesis and storage

the thyroid gland is responsible for secreting what hormones?

• triidothyronine (T3)

• thyroxine (T4)

• thyrocalcitonin

hormonal output from the thyroid is regulated by:

thyroid stimulating hormone (TSH) which is produced by the anterior pituitary gland

blood is supplied to the thyroid by:

4 arteries

2 superior thyroid arteries arise from:

the external carotid arteries and descend to the upper poles

2 inferior thyroid arteries arise from:

the thyrocervical trunk of the subclavian artery and ascend to the lower poles

the corresponding veins (4) of the thyroid drain into the:

internal jugular veins

what transducer is mostly used for scanning the thyroid?

7.5-10.0 MHz linear transducer

standoff pad

a sterile coupling medium for ultrasound applications with a homogeneous structure and a high water content