Thyroid &Parathyroid Flashcards
(29 cards)
The L&R thyroid gland are joined together by
Isthium
The isthmus covers the ___, ___&___ tracheal ring
2,3&4
The gland is surrounded by
a facial sheath derived
from
the pretracheal layer of the
deep cervical fascia
Each lobe is pear shape,
with its apex directed
upward as far as the
oblique line of the thyroid
cartilage; its base lies at
the_____ ring
4
th or 5th tracheal
The 3rd thyroid lobe is often called___&
Is attaches 4rm ____ to ____ and is more to d left
The attachment is made by
Pyramidal lobe
Sup. Isthmus to hyoid bone
Levator glandulae thyroidae
connection to the hyoid bone represent a remnant of a structure called the ______
thyroglossal duct.
Relation of theThyroid Gland
Ant. Lat.
Pst
Mid.
Sternothyroid, Sternohyoid, Sup. Belly of omohyoid, SCM
Pst. Carotid sheath
Mid-above. Pharynx and larynx
Mid. Below. Trachea & oesophagus
Cricothyroid M& Ex. Laryngeal N
The pst. Border of the thyroid gland is related to
Sup&inf parathyroid gland
Anastomosis between the sup. &inf. Thyroid artery
Q: Where does the superior thyroid artery originate from?
A: The superior thyroid artery originates from the external carotid artery.
What’s the blood supply to the thyroid
Sup. Thyroid artery
Inf. Thyroid artery
Thyroidea ima artery
Where does the inferior thyroid artery originate from?
A: The inferior thyroid artery originates from the thyrocervical trunk, which is a branch of the subclavian artery.
What important nerve crosses in relation to the inferior thyroid artery?
A: The recurrent laryngeal nerve crosses either in front or behind the inferior thyroid artery.
What path does the inferior thyroid artery follow behind the thyroid gland? A: The inferior thyroid artery ascends behind the gland to the level of the cricoid cartilage, then curves medially behind the carotid sheath. It reaches the posterior aspect of the gland and descends downward.
What are the veins of the thyroid vein and what do they drain into?
1-Superior thyroid vein = internal jugular vein
2- Middle thyroid vein = internal jugular vein
3- Inferior thyroid
vein = left brachiocephalic vein
The thyroid gland are enclosed in the facial capsule
Location of the sup & inf. Parathyroid gland
Sup= middle of the thyroid
Inf. = inf pole
What is the lymph drainage of the thyroid and parathyroid which are the same
Lymph nodes:
Deep cervical & paratracheal
lymph nodes
The nerve supply of the parathyroid gland
Nerve supply: Superior & middle cervical
sympathetic ganglia
How does the thyroid gland develop?
A: The thyroid gland develops from the endoderm of the floor of the primitive pharynx, specifically at the junction of the anterior two-thirds and posterior one-third of the tongue (foramen cecum). It descends downward in the neck as the tongue grows, positioned anterior to the developing hyoid bone and laryngeal cartilages.
What is the thyroglossal duct?
A: The thyroglossal duct is a narrow tube that connects the developing thyroid gland to the developing tongue. It allows the thyroid gland to descend in the neck during development.
What happens to the thyroglossal duct as the thyroid gland develops?
A: The thyroglossal duct undergoes fibrosis and degeneration as the thyroid gland matures. The upper end of the duct may persist in the dorsum of the tongue as the foramen cecum. In some individuals, the distal part of the duct may persist and form a pyramidal lobe of the thyroid gland.
The pyramidal lobe is attached to the hyoid and isthmus ny
This lobe can be attached to the hyoid bone by fibrous or smooth muscle called Levator thyroidae glandulae.
@ what week/day does the thyroid gland begin to take it’s shape and position and the thyroglosal duct begin to degenerate
7th week/ 50 days
By the____ week the sup. &inf. parathyroid gland develops from
6th week
Dorsal part of the 4th pharyngeal pouch= Sup.
Dorsal part of the 3rd pharyngeal pouch = Inf.
