Endo: Thyroid & Parathyroid Gland Flashcards
Thyroid gland was not documented until the
Renaissance period
In 2700 B.C defined as the enlargement of the thyroid. Give the greek term
Goiter. Guttur.
In 1916, he recognized that goiters arose from the thyroid gland
Hieronymus Fabricius ab Aquapendente
In 1656, the term thyroid gland attributed to ________ in his Adenohraphia. Shield-shaped.
Thomas Wharton
Greek for thyroid
Thyreoeides
In 1776, he classified thyroid as a ductless gland. He thought of functions such as: _______ of the larynx, _______ for blood to provide continuous flow to the brain & ______ women’s neck.
Albrecht von Haller. Lubrication. Reservoir. Beautifying.
In 1179, first accounts of thyroid surgery for the treatment of goiters
Roger Frugardi
The most notable thyroid surgeons that performed thousands of operations with increasingly successful results
Emil Theodor Kocher & C.A. Theodor Billroth
In 1909, he was awarded the nobel prize for medicine in recognition for his works on physio, patho and surgery of the thyroid gland.
Emil Theodor Kocher
From an outpouching of the primitive gut
Thyroid gland
At what week of gestation does your thyroid gland develops
3rd week
Thyroid gland originates at the
Base of the tongue at foramen cecum
Found in the floor of the pharyngeal anlage thicken to form the __________ that descends in the neck anterior to structures that from the hyoid bone and larynx.
Endoderm cells. Medial thyroid anlage.
During its descent, the anlage connected to the foramen cecum via an epithelial-lined tube known as
Thyroglossal duct
The epithelial cells making up the anlage give rise to the
Thyroid follicular cells
The paired lateral anlage originate from the ________ and fuse with the median anlage at approximately the ______ of gestation.
4th branchial pouch. 5th week
Lateral anlages are ________ in origin (________) and provide the _______ producing ________ which thus come to lie in the superoposterior region of the gland.
Neuroectodermal. Ultimobranchial bodies. Calcitonin. Parafollicular/C cells
Thyroid follicles are initially apparent by
8week of gestation
Colloid formation begins by the
11th week of gestation
Developmental thyroid abnormalities
Lingual thyroid, Ectopic thyroid and Thyroglossal duct cyst & sinus “LET”
Most commonly encountered congenital cervical anomalies. ___ week of gestation the thyroglossal duct lumen starts to obliterate, duct disappears by the ___ week of gestation.
Thyroglossal duct cyst. 5th. 8th.
Failure of the median thyroid anlage to descend normally. May be the only thyroid tissue present.
Lingual thyroid
Normal tissue may be found anywhere. Central neck compartment: _______, _______ & ________.
Ectopic thyroid. Trachea, Anterior mediastinum & Esophagus “TAE”
In ectopic pregnancy, thyroid tissue is situated where
Lateral to the carotid sheath and jugular vein
Ectopic thyroid is previously termed as
Lateral abberant thyroid
Almost always represents metastatic thyroid cancer in lymph nodes
Ectopic thyroid
Largest of all endocrine glands. Clasps the pharynx, larynx, esophagus and trachea like a shield.
Thyroid gland
In thyroid gland, each lobe measures ___ extends to the level of ___ tracheal cartilage.
5cm. 6th.
Thyroid gland is composed of right & left lobe. Each lobe has a _____ & _____ pole. Approximately ___ g. Larger in _______. Enlarges during _______. May enlarge slightly during _______.
Superior & Inferior. 20. Women. Pregnancy. Menstruation.
The thyroid gland is posterior to the ______ muscles. Thyroid lobes located adjacent to the ___________. ________ that is just located inferior to the cricoid cartilage.
Strap. Thyroid cartilage. Isthmus.
A pyramidal lobe that ascends from isthmus usually ____ side towards the _______.
Thyroid gland. Left. Hyoid bone.
Thyroid gland may be attached to hyoid bone by fibrous band known as
Levator glandulae thyroidae
Thyroid gland is derived from inferior end of the embryonic
Thyroglossal duct
In normal individual, the pyramidal lobe is ________. In disorders resulting in thyroid hypertrophy the pyramidal lobe usually is _______ & ________.
Not palpable. Enlarged & Palpable.
Thyroid lobes extend to the __________ superior and lie adjacent to the ________ & _________ laterally.
Midthyroid cartilage. Carotid sheats & SCM.
Enumerate the strap muscles
Sternohyoid, Sternothyroid and Superior belly of the omohyoid. “SSS”
The strap muscles are located _______ and are innervated by the ___________.
Anteriorly. Ansa cervicalis/Ansa hypoglossi.
The thyroid gland is enveloped by a loosely connecting fascia that is formed from the partition of the __________ into anterior and posterior divisions.
Deep cervical fascia
Derived from the deep cervical fascia. Attached to cricoid and thyroid cartilages. Thus, moves up and down with larynx during swallowing.
Pretracheal fascia
Is a thin, densely adherent fibrous layer that sends out septa that invaginate into the gland, forming _________.
True capsule of thyroid. Pseudolobules.
The thyroid capsule is condensed into the ____________ near the cricoid cartilage and upper tracheal rings.
Posterior suspensory or Berry’s ligament.
Arise from the ipsilateral External Carotid Arteries (ECA) and divide into anterior and posterior branches at the apoces of the thyroid lobes.
Superior thyroid arteries
In superior thyroid arteries, 1st anterior branch of ECA, descnds the lateral part of the neck under the ___________ and ________ muscles. Above the level of the superior pole, accompanied by the _________ of the superior laryngeal nerve.
Superior belly of omohyoid & Sternohyoid. External laryngeal branch.
Arise from the thyrocervical trunk shortly after their origin from the subclavian arteries. Level of the _______.
Inferior thyroid arteries. 1st rib.
Inferior thyroid arteries, ascends vertically for a short distance to the ________. Turning medially, forming an arching loop and entering the __________. Enter the thyroid lobes at their midpoint.
Carotid sheath. Tracheoesophageal groove.
Inferior thyroid artery crosses the __________, necessitating identification of the RLN before the arterial branches can be ligated.
Recurrent Laryngeal Nerve.
Arises directly from the aorta or innominate. 1-4% of individuals has this. Enter the isthmus or replace a missing _________.
Thyroidea Ima Artery. Inferior thyroid artery.
The venous drainage of the thyroid gland occurs via multiple small surfaces veins, which coalesce to form three sets of veins
Superior, Middle & Inferior Thyroid veins
Veins are the least consistent
Middle thyroid vein
Run with the superior thyroid arteries bilaterally
Superior thyroid veins
The superior and middle veins drain directly into the
Internal Jugular veins
Form a plexus, which drains into the brachiocephalic veins
Inferior thyroid veins
Innervation of the thyroid gland
ANS, Parasympathetic NS & Sympathetic Ns
Parasympathetic fiber innervation of the thyroid gland
Vagus nerve
Sympathetic fiber innervation of the thyroid gland
Superior, Middle & Inferior sympathetic ganglia of the sympathetic trunk
In 1849, the curator of the London Zoological Gardens. First accurate description of the normal parathyroid gland after autopsy examination of an Indian rhinoceros
Sir Richard Owen
In 1879, describes the 1st gross and microscopic of human parathyroids. Glands be named, glandulae parathyroideae.
Ivar Sandstrom
In 1903, recognized the association of hyperparathyroid and the bone disease osteitis fibrosa cystica
Friedrich Daniel von Recklinghausen
In 1925, first successful parathyroidectomy was performed in by
Felix Mandi
In humans, the superior parathyroid gland are derived from the __________, which also gives rise to the ________.
4th branchial pouch. Thyroid gland.
Give rise to the inferior parathyroid gland and the _______.
3rd branchial pouch. Thymus.
The ______ remains closely associated with their respective branchial pouch derivatives.
Parathyroids.
The position of normal __________ is more consistent, with 80% of these glands being found near the posterior aspect of the upper and middle thyroid lobes, at the level of the ________.
Superior parathyroid glands. Cricoid cartilage.
Approximately 1% of normal upper glands may be found in the
Paraesophageal or Retroesophageal space
As the embryo matures, the thymus and inferior parathyroid migrate together ________ in the ______.
Caudally. Neck.
The most common location for inferior glands is within a distance of _____ from a point centered where the __________ & ____ cross.
1cm. Inferior thyroid artery & RLN.
Approximately 15% of inferior glands are found in the
Thymus
The position of the __________, tends to be more variable due to their longer migratory path. The frequency of ________ is about 2%c
Inferior glands. Intrathyroidal glands.
May be found near the skull base, angle of the mandible, or superior to the upper parathyroid glands along with an undescended thymus
Undescended inferior glands
The superior glands are usually __________ at the level of the cricoid cartilage, whereas the inferior parathyroid glands are located ________ to the nerve.
Dorsal to the RLN. Ventral.
Normal parathyroid glands are _____ and ______ in newborns but appear _______ to light brown in adults. Parathyroid color depends on cellularity, fat content and vascularity.
Gray. Semitransparent. Golden yellow.
Normal parathyroid glands are located in. What shape.
Loose tissue or fat. Ovoid.
Size of parathyroid gland
7mm
Weight of parathyroid gland
40-50mg
Hormone secreted by Parathyroid gland
Parathormone
Posterior aspect of the superior pole of the lateral lobes of the thyroid gland and close to the recurrent laryngeal nerve(constant location)
Superior pair
Posterior aspect of the inferior pole of the lateral lobes of tye thyroid gland
Inferior pair
Parathyroid blood supply is derived from
Inferior thyroid artery
Supply at least 20% of upper glands. Branches of the thyroidea ima, and vessels to the trachea, esophagus, larynx and mediastinum may also be found.
Superior thyroid artery
The parathyroid gland drain ________ by the
Ipsilaterally. Superior, Middle and Inferior thyroid veins
Pathologic enlargements of the inferior parathyroid glands may extend to the _______ & _______.
Trachea. Esophagus.
Parathyroid glands maintain serum _______ & _______ levels.
Calcium. Phosphorus.
Parathyroid physiology: maintain the body’s ______ within a very narrow range, so that the _______ and ______ systems can function properly.
Calcium. Nervous & Muscular.
Parathyroid physiology: when blood ______ levels drop below a certain point, ___________ in the parathyroid gland are activated to release _____ into the blood.
Calcium. Calcium sensing receptors. Parathormone.
The left recurrent laryngeal nerve loops around what structure before it ascends back to toward the thyroid area
Aortic arch
What us the main arterial supply of the superior parathyroid gland
Inferior thyroid area
How many percent of individuals has thyroidea ima
1-4%
What is the first anterior branch of the ECA that supplies the thyroid and parathyroid
Superior thyroid artery
In 1903 he was the first person to associate hyperparathyroid and osteitis fibrosia cystic, a disease also associated with his name. Who is this fellow?
Von Recklinghausen, Friedrich Daniel
