S4Anatomy Flashcards
(253 cards)
Which vertebral level is the suprasternal notch located?
T2/T3
Which vertebral level is the thyroid notch located?
C4
Which vertebral level is the lower border of cricoid cartilage located?
C6
Which vertebral level is the hyoid bone located?
C3
Describe the location of the lateral lobe of the thyroid?
The apex extends up to the oblique line of the thyroid cartilage and the base to the level of the fourth or fifth tracheal ring.
Describe the location of the Isthmus of the thyroid?
Crosses anterior to the 2nd, 3rd and 4th tracheal ring.
Describe the location of the Pyramidal lobe of the thyroid?
Projects upwards from the isthmus to the left of the midline.
What encloses the thyroid gland?
A thin connective tissue capsule, from which, septa project into the gland. A loose connective tissue sheath surrounds the gland and the capsule.
From which layer of cervical fascia is this sheath derived?
Pretracheal fascia
Where does the superior thyroid artery arise from?
External Carotid artery
Which nerve runs alongside the superior thyroid artery?
Superior laryngeal nerve
The inferior thyroid artery arises from the thyrocervical trunk. Which vessel does the thyrocervical trunk arise from?
Subclavian artery
Which nerve crosses the inferior thyroid artery?
recurrent laryngeal nerve
What supplies arterial blood to the thymus gland?
the superior and inferior thyroid arteries; the superior thyroid artery supplies the upper pole of each lobe whilst the inferior thyroid artery supplies the posteroinferior aspect
In 10% of the population, a third artery contributes to blood supply of the thyroid. What is it and where does it arise from?
Thyroid ima artery
It may arise from the brachiocephalic trunk or arch of aorta, less commonly from the right common carotid, subclavian or internal thoracic arteries.
Describe the venous drainage of the thyroid.
Three pairs of veins, the superior, middle and inferior thyroid veins drain the superior, middle and inferior parts of the thyroid gland respectively. These vessels form a plexus of nerves on the anterior aspect of the gland.
Into which vein do the superior and middle thyroid veins empty?
Internal jugular vein
Into which vein does the inferior thyroid vein empty?
Brachiocephalic vein
Where does the lymph vessels of the thyroid drain into?
These vessels drain into the prelaryngeal, pretracheal and paratracheal nodes. Efferent vessels from these nodes go to the deep cervical nodes.
What type of innervation does the thyroid receive?
Sympathetic innervation
Where do post ganglionic fibres of the thyroid arise and where do the pass through?
Post ganglionic sympathetic fibres arise in the superior, middle and inferior cervical ganglia and pass through the cardiac, superior and inferior thyroid plexuses to reach the gland.
What type of information is transmitted in Post ganglionic sympathetic fibres of the thyroid?
Vasomotor
What is a thyroid goitre?
An enlargement of the thyroid gland which may occur due to over activity or underactivity of the gland
Which directions does the thyroid gland spread when it is enlarged?
Anterior
Inferior
Lateral
Posterior