<![CDATA[Mock 17 - Thyroid Gland]]>Identify the organ in the picture?
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Thyroid gland

Identify different parts?
Left lobe
Right lobes
Isthmus
Pyramidal lobe

Blood supply and lymphatic drainage
Category Details
Arterial

  • Superior thyroid artery (1st branch of external carotid)
  • Inferior thyroid artery (from thyrocervical trunk from subclavian a. 1st part)
  • Thyroidea ima (in 10% of population -from brachiocephalic artery or aorta)

Venous

  • Superior and middle thyroid veins - into the IJV
  • Inferior thyroid vein - into the brachiocephalic veins

Lymphatic drainage

  • Pre-laryngeal
  • Pre-tracheal
  • Para-tracheal
  • Upper and lower deep cervical
  • Brachiocephalic lymph nodes.

What is the Nerve supply?
The 3 cervical ganglions (superior, middle and inferior) but mainly the middle.

Embryology of thyroid?
The thyroid gland develops from the foramen caecum (2/3 along the length of the tongue from the tip) → to pass forward and loop around and beneath (under) the hyoid bone.

What is thyroglossal cyst?
A fibrous cyst that forms from a persistent thyroglossal duct.

What is the Supply of RLN?
Supplies all intrinsic laryngeal muscles except cricothyroid muscle.
Sensory innervation of the mucous membranes of the larynx below the vocal cords.

What nerves could be damaged during thyroidectomy?
Recurrent LN
External LN
Cervical sympathetic chain

What is the clinical RLN injury:
Unilateral RLN injury
Diplophonia
Hoarseness
Dysphagia

Bilateral RLN injury
Aphonia, inability to speak or cough.
Respiratory compromise

ELN injury
Abnormalities in pitch.
Inability to sing with smooth change to each higher note (glissando or pitch glide)

Sympathetic chain
Horner's syndrome (ptosis, myosis, anhidrosis)

]]>https://isurg.org/topic/429/mock-17-thyroid-glandRSS for NodeMon, 06 Apr 2026 05:51:24 GMTSun, 29 Mar 2026 06:38:21 GMT60<![CDATA[Reply to Mock 17 - Thyroid Gland on Sun, 29 Mar 2026 06:43:52 GMT]]>Vagus Nerve Course in Thorax & Abdomen
Thorax:Left Vagus NerveRight Vagus NerveCrosses in front of the left subclavian artery. Enters the thorax between the left common carotid and subclavian arteries.Crosses in front of the first part of the subclavian artery.Descends on the left side of the aortic arch. Travels behind the phrenic nerve.Travels behind the innominate vessels. Reaches the thorax on the right side of the trachea.Courses behind the root of the left lung. Deviates medially and downwards to reach the esophagus and form the esophageal plexus with the right vagus nerve.Inclines behind the hilum of the right lung. Courses medially towards the esophagus to form the esophageal plexus with the left vagus nerve.

Abdomen:The esophageal plexus, formed by the union of the right and left vagus nerves. The vagus nerve enters the abdomen through the esophageal hiatus at the level of the tenth thoracic vertebra (T10). It divides into the anterior and posterior vagal trunks, which innervate the stomach, small intestine, liver, gallbladder, pancreas, and spleen.

Nerves in esophageal hiatus?Ant & post vagal trunks.

What do they supply?Stomach, duodenum, jejunum, ileum, cecum, ascending colon, medial 2/3 of transverse colon, spleen, pancreas, gall bladder.

Muscle dissected to see thyroid?Sternohyoid muscle

]]>https://isurg.org/post/617https://isurg.org/post/617Sun, 29 Mar 2026 06:43:52 GMT