Anatomy of Thyroid and Parathyroid glands Flashcards
What do the lobes of the thyroid gland attach onto?
lateral aspects of the thyroid & cricoid cartilages & to the trachea
Which level of cartilage does the isthmus lie anterior to?
2nd and 3rd tracheal cartilages
thyroid gland spans from C5 and T1
A goitre will move in which directions on swallowing?
superiorly then inferiorly
Where are the parathyroid glands located?
on the posterior surfaces of the thyroid gland’s lateral lobes
What is a pyramidal lobe?
a variation in structure of the thyroid gland where there is an incomplete isthmus
the result is an extension of the left lateral lobe superiorly to attach to the thyroid cartilage - can extend as far up as the hyoid bone
what is the thyroglossal duct?
embryological structure which connects the descending thyroid gland to the tongue
What is ectopic thyroid tissue and where is it found?
aka. thyroglossal duct cysts, are cysts which arise from the thyroglossal duct and can be found at any position in the migratory path of the gland from the foramen caecum
What are the platysma muscles?
skeletal muscles in the superficial fascia of the neck - belong to the muscles of facial expression
What is the nerve supply of the platysma muscles?
CN VII
Name the fascial compartments of the neck.
Pre-vertebral (deep) fascia
Investing fascia
Pre-tracheal fascia
2 Carotid sheaths
Which fascial compartment contains postural neck muscles & cervical vertebrae?
Pre-vertebral (deep) fascia
located posteriorly
Which compartment contains all but one of the facial compartments?
investing fascia - also encloses 2 pairs of muscles - trapezius and sternocleidomastoid
What do the carotid sheaths of the neck contain?
vagus nerves
deep cervical lymph nodes
carotid arteries
internal jugular vein
What is the contents of pre-tracheal fascia?
oesophagus, trachea, thyroid gland, strap muscles, recurrent laryngeal nerves
Which cranial nerve supplies the muscles located in the investing facia compartment?
CN XI (spinal accessory) supplies SCM and trapezius
Name the 2 heads of the SCM muscle and where they attach.
Sternal head - manubrium of sternum
Clavicular head - medial end of clavicle
Both heads pass superiorly to attach to mastoid process of temporal bone.
What is the blood supply to the thyroid and parathyroid glands?
External carotid artery, 1st branch = superior thyroid artery (anterior/superior aspect)
Right subclavian artery -> inferior thyroid artery (posterior-inferior aspect)
Brachiocephalic artery -> thyroid ima artery (present in 10%); anterior aspect & isthmus
What is the venous drainage fo the glands?
superior and middle thyroid veins drain into internal jugular veins, then brachiocephalic.
inferior thyroid vein drains into brachiocephalic -> SVC
Where do the left and right recurrent laryngeal nerves recur?
right - under subclavian artery
left - under arch of aorta
Name the strap muscles.
Sternohyoid
Sternothyroid
Thyrohyoid
Omohyoid
What is the purpose of a fascial sling in relation to the omohyoid?
attaches the intermediate tendon of the omohyoid to the clavicle
What are the borders of the anterior triangle of the neck?
inferior border of mandible
midline of neck
sternal head of SCM
Apex at jugular notch (of manubrium)
What are the borders of the posterior triangle?
clavicular head of SCM
trapezius muscle
right clavicle
Air moves through which opening in the trachea?
rima glottis - opening between vocal cords
What is Berry’s ligament?
a suspensory ligament on posterior surface of thyroid gland which attaches it to mostly cricoid cartilage
