Anatomy of Thyroid and adrenal Flashcards
Embryogenesis of thyroid (basic)
From part of Arch 3 (thyroid anlage), pyramidal remnant can remain at top
Vasculature of the thyroid
Thyroid is extremely vascular. Can’t remove just a nodule because it will bleed. Superior thyroid artery (one of first branches off carotid) and inferior thyroid artery, Middle and inferior thyroid veins.
Other structures around thyroid
Recurrent laryngeal nerve (from vagus, for speaking and sense) b/w thyroid and trachea (can get mixed b/w blood vessels), ext. branch of superior laryngeal nerve (for projection of voice) from above. Trachea obviously. Parathyroid on the 4 corners.
Abnormal pathology of thyroid
Usually nice columns with colloid space in b/w. Abnormal: stacks of cells, looks messy.
Thyroid cancer.
Most are benign, usually don’t cause mortality. But they can pinch off the trachea and make it difficult to make an emergency airway.
Safe removal of thyroid
Avoid damaging voice nerves, leave parathyroid intact (avoid hypocalcemia). Cut middle thyroid vein.
Layers of the adrenal
Superficial: Zona glomerulosa, fasciculata, reticularis, then medulla
Cushing’s syndrome basics.
Hypercortisol. Fat deposition on abdomen and shoulders, moon face, bruise easily
Excess 17-keto-steroids (androgens)
(in women) acne, hirsuitism, small breasts, musculature
Structures around adrenals
Small! <1cm! On top of kidneys. Quite vascular, lots incoming but only one outgoing - suprarenal/adrenal v. (clip before surgery so epinephrine isn’t released). Psoas muscle is deep to it. L side: spleen, pancreas, transverse colon, lots of other vessels around it. R side: under vena cava, arteries from retroperitoneal area,
Adrenal tumors
Not as common as thyroid. Often functional (secretes excess hormone so needs removal) but can be non functional (only remove when large/malignant)
Surgical tips and considerations for adrenal
Laparoscopic mostly. watch the big vessels, like the vena cava
