Thyroid/ Parathyroid Gland
Parathyroid Gland
Four disc-shaped glands, embedded in the posterior aspect of the thyroid gland. Produces hormones: Parathyroid hormone (PTH): controls the metabolism of calcium and phosphorous in the blood.
Thyroid and Parathyroid Gland - Lymphatics
prelaryngeal nodes ↓ pretracheal nodes ↓ paratracheal nodes then to superior deep cervical nodes or inferior --> jugular lymphatic trunks---> thoracic duft L or R lymphatic duct
Thyroid Gland
-Butterfly shaped endocrine gland located at the C5-T1 vertebral level in the neck -Deep to the sternothyroid and sternohyoid muscles -The right and left lobes are connected by an isthmus over the trachea =====>A pyramidal lobe is a variant and may be present in 10-30% of people Function -Produces thyroid hormones (T3/T4) and calcitonin
Thyroid and Parathyroid Gland- Veins
1 - Superior poles of the gland Superior thyroid veins (accompany superior thyroid artery) ↓ Internal jugular vein 2 - Middle of the lobes of the gland Middle thyroid vein (run with inferior thyroid artery) ↓ Internal jugular vein 3 - Inferior poles of the gland Inferior thyroid veins ↓ Brachiocephalic veins
Thyroid and Parathyroid Gland - Innervation
Parasympathetic: -CN X (nerve fibers arising from the superior laryngeal nerve and the recurrent laryngeal nerve) Sympathetic: Remember, 2-neuron chain originating from the spinal cord (T1). Post-ganglionic axons originate in the the superior cervical ganglion to target the glands.
Thyroid and Parathyroid Gland- arteries
Supplies antero-superior aspect of thyroid gland External carotid artery ↓ Superior thyroid artery (1st branch) Supplies postero-inferior aspect Subclavian artery ↓ Thyrocervical trunk ↓ Inferior thyroid artery
