Tempkin: Thyroid and Parathyroid
In children and newborns the gland is approximately _______cm long, _________cm anteroposteriorly, and ____cm at its greatest width.
2-3; 0.2-1.2; and 1.5
The average normal adult thyroid gland is approximately ______cm long, _____cm anteroposteriorly, and ______ cm at its greatest width
4 to 6; 1.3 to 1.8; 3
The oval bean shaped parathyroid glands are approximately ______mm long, _______mm thick, and _____mm wide.
5-7; 1-2; and 3-4
What transducer is used to scan the thyroid?
7.5-10 MHz high resolution, real-time linear transducer
What is a Pyramidal lobe?
a normal variant of the thyroid gland in which there is a superior extension of the isthmus appears the same as normal thyroid gland - triangular shaped present in 15-30% of thyroid glands
The thyroid gland is
an endocrine gland
The thyroid gland is located on the _____ side of the trachea
anterior
The thyroid lies between
anterior strap muscles and the posterior colli muscle and minor neurovascular bundle
How much does the thyroid weigh?
approximately 25-35g
Normal parathyroid glands
are occasionally identified in young children
The best way to image the inferior portion of the thyroid lobes is to
have the patient swallow
The long axis of the isthmus is situated ______ and viewed from a _______ scanning plane at the midline of the neck,
horizontally, transverse
The thyroid gland is _____ relative to the strap muscles
hyperechoic
The thyroid gland is located _______
in the lower, anterior portion of the neck, anterior to the trachea and inferior to the larynx
The main function of the thyroid hormones is to ________.
increase metabolism
The size of the thyroid gland is
influenced by body habitus
The thyroid gland is connected in the midline by the
isthmus
The thyroid gland has two lateral _________ connected by the ___________.
lobes; isthmus
What does the parathyroid secrete and what is its function?
parathormone (PTH) which acts as the antagonist for calcitonin and controls calcium levels in the bloodstream
The longus colli muscle is located
posterior to each thyroid lobe
The parathyroid glands lie between the _____ aspect of the thyroid gland and the ______.
posterior; longus colli muscle
What is best identified as an echogenic rim located between the trachea, esophagus, and left posterior thyroid lobe?
recurrent laryngeal nerve
The isthmus of the thyroid gland unites the lobes at the level of the
second, third, and fourth tracheal rings
The normal thyroid gland generally appears as
uniform echoes, isosonic to liver parenchyma
What is visualized by a hypoechoic dot posterolateral to the thyroid lobe, usually between the carotid artery and jugular vein?
vagus nerve
Each lobe is oriented ________ in the neck, therefore, the long axes are visualized in _______ scanning planes
vertically, sagittal
The thyroid gland is a ductless gland that directly secretes which hormones into the bloodstream.
-T4 & T3 (reg. metabolism) -Calcitonin (decreases blood calcium levels)
The lobes of the thyroid gland are bordered laterally by the ______ and _______
common carotid artery, internal jugular vein
What are the Variant parathyroid gland shapes?
elongated (11%), bi-lobed (5%), or multi-lobed (1%)
What is seen just left of the midline of the neck, posterior to the left thyroid lobe, between the trachea and longus colli muscle?
esophagus
What do the secreted thyroid hormones regulate?
metabolic rate, metabolism of lipids, proteins, and carbohydrates, and the absorption of calcium from the blood for storage in the bones
What are Dilated follicles?
normal variant interspersed throughout the thyroid and appear as 1-3mm cystic areas
What is an Ectopic thyroid?
normal variant lingual thyroids account for 90% of ectopic thyroids
The thyroid gland is highly vascular and its blood supply consists of____
paired superior and inferior arteries and veins, often middle thyroid veins
What are the anterior strap muscles?
sternocleidomastoid, sternohyoid, and strenothyroid
The long sections of the lobes appear sandwiched between the _______ anteriorly and _______ and posteriorly
strap muscles, longus colli muscles
The best patient position to scan the thyroid gland is
supine, neck mildly hyperextended
The best approach when scanning the thyroid gland is
to use a light touch with the transducer