Atlas of Human Anatomy by Netter

FACTS & HINTS

High-Yield Facts

Clinical Points
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Severance of recurrent laryngeal nerve

Recurrent laryngeal nerve (supplies intrinsic muscles larynx)

Is closely associated with inferior thyroid artery and needs to be avoided during neck surgery

If unilateral damage, voice hoarseness may result because one vocal fold cannot approximate the other.

If bilateral damage, loss of voice will result because vocal folds cannot approximate each other (be adducted)

Clinical Points

Thyroid lumps

Lumps in thyroid can be single, multiple

Solitary nodules are likely to be benign (80%)

Investigation includes: history, examination, and fine-needle aspiration of the gland for cytology and radionucleotide imaging

Most common malignant is papillary thyroid cancer

Treatment is total thyroidectomy

Clinical Points

Hyperthyroidism

Medical condition with increased activity of the thyroid gland

Results in excessive amount of circulating thyroid hormones

Leads to increased rate of metabolism

Affects about 1% of women and 0.1% of men

Thyrotoxicosis is a toxic condition caused by an excess of thyroid hormones from any cause.

Hyperthyroidism with diffuse goiter (Graves' disease)

Most commons cause of hyperthyroidism in patients younger than 40 years.

Excess synthesis and release of thyroid hormone (T 3 and T 4 ) result in thyrotoxicosis,

Thyrotoxicosis upregulates tissue metabolism and leads to symptoms indicating increased metabolism.

Mnemonics

Memory Aids

Table I00-2. Cartilages of the Larynx

Four cartilages in the larynx: TEAC

Thyroid, Epiglottis, Arytenoid, Cricoid

Note: TEAC is a brand name of a home stereo. Associate the TEAC sound with the vocal cords and you can make a connection.