Normal Neck and Thyroid/Parathyroid Glands Flashcards
Salivary Glands
Accessory digestive glands that produce a fluid secretion called ______
Saliva functions include:
Solvent in cleansing the ______
Dissolving food particles so that they may be ______
Lubricate the ______ with starch-digesting enzymes and mucus to facilitate ______
3 Major pairs of salivary glands:
1) Parotid Gland
______ salivary gland
located ______ and ______ to ear b/t skin and muscle of chewing (masseter)
______ duct (Stensen’s) carries contents/drains into the mouth opposite 2nd molar
2) Submandibular Gland
2nd largest salivary gland; Has a muscular covering located inferiorly to ______ midway along inner side of jaw
Empties contents by way of ______ (Wharton’s) duct into floor of the mouth on both sides of neck
3) Sublingual Gland
______ salivary gland
lies under the floor of the mouth and on both sides of the ______
Possesses several small ______ ducts that empty into the floor of the mouth in an area posterior to the submandibular duct
saliva teeth tasted pharynx swallowing largest anteriorly inferiorly parotid mandible submandibular smallest tongues sublingual
Pathology of Salivary Glands: Cysts & Solid Tumors
A. ______:
types include true, dermoid, ductal, mucous, retention and mucoceles
anechoic on Ultrasound
B. Solid Tumors
Incidence
65-80% of salivary tumors are ______ (15% are malignant)
10% are ______ (40% are malignant
9% are in minor salivary ______ (90% are malignant
1% are ______ ( 90% are malignant)
Majority of salivary glands are epithelial in origin
Benign Tumors Plenomorphic \_\_\_\_\_\_ (mixed tumor) – most common benign tumor; comprises 60% of parotid tumors
______ Tumor (Adenolymphoma) – 2nd most common benign tumor
Malignant Tumors
Mucoid Epidermoid – most common malignant tumor; found mainly in the ______ gland
Adenoid Cystic Carcinoma – rare in parotids; most common malignant neoplasm of the ______ glands
SONO Finding:
Benign neoplasms tend to be less echogenic than normal parenchyma
Malignant neoplasms are inhomogeneous lesions with irregular and ill-defined borders
Unilateral gland enlargement
cysts parotid submandibular glands sublinguinal adenoma warthin's parotid salivary
C. Enlargement (Sialosis, Asymptomatic Parotid Enlargement)
Non-neoplastic, ______ chronic, or recurrent enlargement of the ______ glands
Associated with malnutrition, ______ cirrhosis and ______
A common disturbance of ______ glands in adults
Sono Finding: Non-specific glandular enlargement
D. Inflammation with Sialadenitis/Infection
May be ______, ______, or auto immune in origin
Most common autoimmune dz is Sjogren’s syndrome, which can lead to glandular destruction
Most common viral infection is ______ mainly involving the parotid
Predisposing factors to infections include obstruction of ______, debilitation, ______, irradiation, drug suppression of salivary secretions, immunosuppression
Sono Finding: Non-specific glandular enlargement; inhomogenous parenchyma; US can be used to check for abscess formation
E. Sialolithiasis (STONES ) with Sialadenitis/Infection
80% - ______; 19% - ______; 1% - ______
Only ≈ 20% shown on conventional X-ray
Salivary ______ (sialoliths) are made primarily of calcium carbonate and calcium phosphate form due to several factors (saliva pH, mucous contents of glands, obstruction of orifices by impacted food debris or edema) 20 in frequency to mumps as a dz of the salivary glands
Occurs X2 in ; peak 30-50 years
Dilatation of ducts is often associated with ______ and/or strictures
S/S: Pain, swelling of glands, pus draining into mouth
Sono Findings: Enlarged hypoechoic glands; echogenic focus with acoustic shadow; can have multiple calculi within duct and/or gland; ↑ blood flow (hypoervascularity) o n CFD
non-inflammatory salivary alcoholic diabetes parotid viral bacterial mumps duct dehydration submandibular parotid sublingual calculi stones
Thyroid Sonography
For most ultrasound exams, the patient is positioned lying face-____ on an examination table that can be tilted or moved.
A pillow may be placed behind the ______ to extend the area to be scanned for a thyroid ultrasound exam. This is especially important for a small child with very little space between the chin and the chest.
A clear ______-based gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin that can block the sound waves from passing into your body.
The sonographer or radiologist then presses the ______ firmly against the skin in various locations, sweeping over the area of interest or angling the sound beam from a farther location to better see an area of concern.
When the examination is complete, the patient may be asked to dress and wait while the ultrasound images are reviewed.
This ultrasound examination is usually completed within ______ minutes
up neck water transducer 30
The Thyroid
Embryology
Earliest endocrine glandular structure to appear in the human embryo
Arises from a median, sac-like endodermal diverticulum; thickens during ____ embryonic week
Stalk between thyroid and tongue is called ______ duct cyst; opens in embryo at base of tongue; atrophies at 6th embryonic week; if persists, cysts, fistula or accessory pyramidal lobe may develop
______ week – thyroid has divided into 2 lobes with an isthmus
______ embryonic week thyroid follicles begin to form; acquire colloid by 3rd month of development
Physiology
Plays a major role in growth and development; regulates basal metabolism by the ______, ______ and ______ of thyroid hormones
Function
Normal = euthyroid
______ = hypothyroid
______ = hyperthyroid
Hormonal secretion by thyroid is regulated by ______ and ______ gland; secretion 10 controlled by TSH (thyroid stimulating hormone)
Triiodothyronine (T3) - ≈ ______%
Thyroxine (T4) – 10 hormone secreted by thyroid ≈ ______%
c. Calcitonin
When thyroid hormone is needed, TSH and thyrotropin are secreted and releases hormones into bloodstream.
3rd thyroglossal 7th 8th synthesis storage secretion decrease increase hypothalamus pituitary 10 90
Lab Values
T3 Resin Uptake (RT3U):
____ levels – Hyperthyroidism, T3 thyrotoxicosis, thyroditis, toxic adenoma
____ levels – Hypothyroidism, starvation, chronic illness
______: not the best marker but is considerered screening test
______ levels - 10 hypothyroidism (thyroid dysfunction), thyroiditis, thyroid agenesis, congenital cretinism
______levels - 20 hypothyroidism (pituitary dysfunction), hyperthyroidism, pituitary hypofunction
T4: better marker to determine b/t hypo/hyper thyroidism
______ levels – hyperthyroid states (e.g., Graves’ dz, Plummer’s dz, toxic thyroid adenoma), acute thyroiditis, pregnancy, oral contraceptives use
______ levels – Hypothyroid states (e.g., cretinism), protein malnutrition, renal failure)
Calcitonin: marker to determine cancer vs hyperthyroidism
______ levels – Medullary carcinoma of the thyroid, oat cell CA of the lung, breast CA; pancreatic CA, 10 hyperparathyroidism
______ levels – 20 Hyperparathyroidism because of chronic renal failure, Zollinger-Ellison syndrome, pernicoous anemia, alcoholic cirrhosis, thyroiditis
increases decreases TSH increases decreases increase decrease increase decrease
Normal Anatomy and Location
Largest endocrine gland
consist of: ___ lobes and isthmus
RT and LT lobes of the thyroid gland are situated in the lower part of the neck, inferior to the ______ and anterior and on either side of the ______
lobes are connected across the midline by the ______ (typically at the inferior poles)
Size
size and wt vary with ______ and ______;
>; ↑ age ↑ size
Adult – Weight = ____-____ gram
Lobe Size: (L) ____-____ cm, (AP) ____-___ cm,
(W) ____-____ cm
Isthmus (AP) ___-___ mm
External Structure - 2 thin layers of connective tissue;
(1) 1st = ____-______ fascia (false thyroid capsule);
(2) 2nd = true ______ capsule, adherent to gland surface
Internal Structure - ______ composed of follicles (glandular epithelium and colloid), connective tissue, stroma, blood vessels, nerves and lymphatics
2 larynx trachea isthmus sex age 25 35 4 6 2 3 1.5 2 2 6 pre-tracheal thyroid parenchyma
Pyramidal Lobe of Thyroid
a Nl variant
seen as a “____” thyroid lobe
present in ____-____% of the population
likely related to a remnant of the ______ duct
arises from the isthmus upwards along the ML or is
shifted towards the LT of the ______
usually located anterior to the ______ cartilage
can be involved in any diffuse thyroid parenchymal disease
third 10 30 thyroglossal neck thyroid
Arterial Supply to the gland
The thyroid is supplied with arterial blood from the:
- ______ thyroid artery, a branch of the external carotid artery.
- ______ thyroid artery, a branch of the thyrocervical trunk.
- sometimes by the ______ ima artery, branching directly from the subclavian artery.
superior
inferior
thyroid
Venous Drainage
venous blood is drained via:
- ______ thyroid veins, emerges from the apex of each lateral lobe, draining in the internal jugular vein.
- ______ thyroid veins, emerges from the the lower part of each lateral lobe.
- ______ thyroid veins, emerges from the isthmus and lower part of the lateral lobe. draining via the plexus thyreoidea impar in the left brachiocephalic vein.
superior
middle
inferior
Adjacent Structures
____ glands - adjacent to the posterior surface of the thyroid gland
The ______ in the midline gives a characteristic curvilinear reflecting surface with associated reverberation artifact
Esophagus
Is hidden from sonographic visualization by the ______
A segment may swing ______ usually toward the left and may lie adjacent to the posteromedial surface of the thyroid
It can be identified by the characteristic sonographic “______” appearance of bowel in the transverse plane
This segment of the esophagus should not be mistaken for a ______ or ______ mass
______ Neurovascular Bundle – CCA, IJV, and vagus nerve encased by the carotid sheath
Carotid Artery – Lateral to each lobe
Internal Jugular Vein – Lateral to the CCA and each lobe
______ Neurovascular Bundle – inferior thyroid artery, recurrent laryngeal nerve mark the posterior border thyroid of the thyroid
parathyroid trachea trachea laterally target thyroid parathyroid major minor
Parathyroid
4 parathyroid glands (2 ____ and 2 ____)
Located to the ______ surface of the thyroid gland
the superior pair are typically ______ to the mid portion of each lobe of the thyroid
the inferior pair usually lie at the ______ border of the thyroid
normally ___ x ___ x ___ mm in size; different shapes
____% of parathyroid glands lie in ectopic locations
Common ectopic locations
(1) ______
(2) ______
(3) ______
(4) Undescended near the ______ bifurcation
superior inferior posterior posterior lower 5 3 1 1.3 retrotracheal mediastinal intrathyroid carotid
Parathyroid Glands
The _____ glands, which lie behind the thyroid, secretes parathyroid hormone to help regulate calcium metabolism
Usually ____-____ glands in number (2 on each side) but can vary b/t 3-6
Each about the size of a grain of rice.
Though they’re located near each other, the parathyroid glands are not related to the ______ gland.
parathyroid
3
4
thyroid
Physiology
Primary hyperparathyroidism
Usually suspected because of an increased serum calcium level on routine screening
Causes:
(a) A single adenoma (echogenicity of parathyroid adenomas is less than that of thyroid tissue) in ___ to ___% of cases
(b) Multiple gland enlargement (hyperplasia) in ____ to ____% of cases
(c) Carcinoma in less than ___% of cases
(d) Stone formation occurs in about ___% or more of the cases
(e) Multiple gland enlargement occurs in more than ____% of patients with multiple endocrine neoplasia, type I (MEN I)
Secondary hyperparathyroidism
Characteristically is found in patients with chronic renal failure
The inability of the kidneys to filter results in ______ amounts of serum phosphates which depress the serum calcium level which stimulates the parathyroid glands to become hyperplastic
Pathology
Pathology
1. Parathyroid ______
Most commonly oval; often asymmetric; most are 0.8-1.5 cm long
- ______ adenomas may have elevated serum calcium
Vast majority hypoechoic and homogeneously solid by US
Parathyroid ______
Usually larger than adenomas; frequently lobulated contour, heterogeneous texture
increased 80 90 10 20 1 70 90 increased adenoma larger carcinoma
