Thyroid And Parathyroid Glands
What are the glands that regulate thyroid hormones?
1. P - Pituitary 2. Hypothalamus
What are the strap muscles?
1. Sternothyroid 2. Sternohyoid 3. Omohyoid
10. Three muscle groups that surround the gland and may serve as landmarks are:
1. Strap muscles2. Sternocleidomastoid muscle 3. Longus coli muscles
______ what are the serum thyroid hormones?
1. T4 - Thyroxine 2. T3 - Triiodothyronine
The thyroid gland is enlarged if the AP measurement of the isthmus is greater than--------------
1cm
How many parathyroid glands are located posterior to the thyroid?
4
Transducer choice for scanning the thyroid gland is:
6-15 MHz linear. 7.5 MHz recommended for a very muscular or fat neck
Pyramid lobe also called:
Accessory lobe
Strap muscles are _________ to the thyroid.
Anterior
Sternocleidomastoid is _________ to the thyroid.
Anterolateral
_______ is congenital total or partial absence of thyroid gland.
Aplasia of the thyroid gland
What is directly lateral and posterior to the thyroid lobes?
CCA
What does the major neurovascular bundle consist of?
CCA, Internal Jugular vein, vagus nerve
Act opposite parathyroid hormone
Calcitonin
_____ decrease blood calcium levels.
Calcitonin
_____ helps regulate calcium metabolism.
Calcitonin
When you are unable to find the thyroid gland what is the next thing to do:
Check for ectopic thyroid
Parathyroid glands produce:
Endocrine gland that produces parathyroid hormone (PTH)
What is usually hidden from the sonographic visualization by the trachea?
Esophagus
_____ is seen to the left of the midline posteromedial to left lobe of the thyroid.
Esophagus
Superior thyroid arteries are branches of what?
External carotid arteries
Thyroid is located superior to the thyroid cartilage of the larynx (voice box).T/F
False. It is located inferior to the thyroid cartilage of the larynx (voice box).
The parathyroid glands are supplied by:
Fed by branches of the superior & inferior thyroid arteries
A surplus of these T3 /T4 will produce____ and a reduction will cause _____.
Hyperthyroidism/Hypothyroidism
Sonographically how muscles appear?
Hypoechoic with echogenic linear structures inside
What is the venous blood from the thyroid drained into?
IJV
What vessel is lateral to the CCA?
IJV
What does the minor neurovascular bundle consist of?
Inferior thyroid artery recurrent laryngeal nerve
The superior & middle thyroid veins drain into what?
Innominate veins
The right and left lobes of the thyroid are connected by the:
Isthmus
The AP measurement of the thyroid gland is:
Isthmus = 2-6 mm
The function of thyroid gland is:
It releases hormones that control metabolism growth and development
Normal size of parathyroid glands is:
Less than 5 mm
The most common location of ectopic thyroid is:
Lingual
What is seen posterior to the thyroid?
Longus colli muscle
_____ is sonographically seen as a vague hypoechoic area between the longus colli muscle & the thyroid gland.
Minor neurovascular bundle
The ________ is composed of the nerve and thyroid vessels.
Neurovascular bundle
Is the normal parathyroid gland seen sonographically?
No
What is a pyramid lobe?
Normal variant extending superior to the isthmus
Pyramid lobe is frequently located:
On the left
What are some of the clinical indications for thyroid us:
Palpable neck mass clarifying location of a palpable neck mass (intra or extrathyroid). Enlarged thyroid gland. Abnormal areas on a nuclear medicine study. To differentiate between cystic & solid masses. For guided biopsy assisting in fine-needle biopsy for determination of diagnosis and treatment. (FNA). Abnormal T3 or T4 levels. Increased calcium levels (parathyroid adenoma). Screening of patients at risk for thyroid carcinoma. Serial follow-up of suspected benign lesions (documenting size)
____ increases blood calcium levels.
Parathyroid hormone
____ increases the level of calcium in the blood.
Parathyroid hormone (PTH)
What is thyroid-stimulating hormone produced by?
Pituitary gland
Longus collie muscle is _________ to the thyroid.
Posterior
Minor neurovascular bundle is _________ to the thyroid.
Posterior
Parathyroid glands are _________ to the thyroid.
Posterior
Parathyroid glands are located ___ to the thyroid?
Posterior
The normal size of the thyroid gland is:
SAG measurement = 4-6CM TRV measurement = 1-2 cm AP measurement = 1-2 cm
Bilateral, thin, along the anterior lateral surface of the thyroid glands are:
Strap muscles
The blood is drained from the thyroid gland into the IJV via what?
Superior & middle thyroid veins
Where does the thyroid arterial supply come from?
Superior thyroid arteries Inferior thyroid arteries
Patient position for scanning thyroid gland is:
Supine. Neck hyperextended by placing a sponge or pillow under the patient's neck
What can the patient due to help identify the esophagus?
Swallow
The thyroid normally produces more _____ than _____.
T4/ T3
Hypothalamus releases _______
TRH (thyroid releasing hormone)
What may be mistaken for an enlarged parathyroid gland?
The minor neuromuscular bundle
What does thyroid-stimulating hormone stimulate?
The thyroid to produce thyroid hormones
Inferior thyroid arteries are branches of what?
Thyrocervial trunk
_____ is characterized by incomplete development of the thyroid gland that results in primary congenital hypothyroidism.
Thyroid hypoplasia
Right and left lobes of the thyroid gland are situated in the lower part of the neck along either side of the what?
Trachea
Isthmus is midline anterior to trachea. T/F
True
The Right lobe of the thyroid tends to be larger than Left. T/F
True
Thyroid is one of the largest endocrine glands. T/F
True
Sonographically how does the longus colli muscle appear?
Wedge-shaped sonolucent structure adjacent to the cervical vertebrae
