Thyroid Gland Anatomy
Thyroid is a large ductless gland that secretes hormones that control metabolism.It is located in the base of your neck below the Adam's apple,situated between C5 and T1 vertebrae.It is a butterfly shaped structure that is divided into two lobes, that are connected by isthmus.
Relations of thyroid gland
It has two borders and three surfaces
- Anterior and posterior borders
- Medial,lateral and post-lateral surfaces
It is covered by
- Sternohyoid
- superior belly of omohyoid
- sternothyroid
- Anterior border of sternocleidomastoid
- Trachea and oesophagus
- carotid sheath and overlaps common carotid artery
- Anterior branch of superior thyroid artery
- Parathyroid glands
- On left side thoracic duct
Muscles
The muscles associated with thyroid gland are
- Sternocleidomastoid muscle
- Sternothyroid muscle
- Sternohyoid muscle
- Sternocricoid muscle
Membranes
It has two membranes associated with it
- Thyrohyoid membrane
- Cricothyroid membrane
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| anterior neck muscle |
BLOOD SUPPLY
Artery
- Carotid Artery
- Superior and inferior thyroid arteries
- Superior,middle and inferior thyroid veins
- Jugular vein
NERVE SUPPLY
- Vagus nerve
- cervical ganglion
Physiological anatomy of thyroid gland
- Thyroid gland is composed of a large number of closed follicles(100 to 300 micrometer in diameter)filled with large number of secretory substance called colloid.
- And is lined with cuboid epithelial cells which secretes into the follicle, a glycoprotein called thyroglobulin,which contains the thyroid hormones.
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| anatomy and physiology |
