Anatomy of the Thyroid Gland Flashcards
What is the thryoid usually made up of?
2 lateral lobes and an isthmus
Where do the thyroid lobes attach?
Lateral aspects of the thyroid and cricoid cartilages and to the trachea
Where does the isthmus lie?
Anterior to the 2nd and 3rd trachael cartilages
If the thyroid gland is enlarged or there is a lump, which direction will it move?
Superiorly then inferiorly with the larynx during swallowing
How many and where are the parathryiod glands located?
4 - The posterior surface of the thyroid glands lateral lobes
What do 22-55% of the population have with regard to the anatomy of the thyroid gland?
A pyrimidal lobe
What and where are the platysma muscles?
Belong to the group of “muscles of facial expression” and are locted immediately deep to the skin, within the superficial fascia of the neck
What nerve supplies the patysma muscles?
Cranial nerve VII (facial nerve)
Name the 4 fascial compartements of the neck?
Investing (deep) fascia
Carotid sheaths
prevertebral fascia
Pretracheal fasica
Where is and what is the purpose of the investing fascia?
Foud deep to the superficial fascia and encloses all other neck compartments and the trapezius and sternocleidomastoid muscles
Where is the prevertebral fascia found and what does it enclose?
Posteriorly and deep to the investing fascia
encloses the cervical vertebrae and the postural neck muscles
Where are the 2 carotid sheaths?
Deep to the investing fascia & located anterolaterally in the neck either side of the thyroid gland
What is contained within the carotid sheaths?
- internal jugular veins
- vagus nerves
- carotid arteries
- deep cervical lymph nodes
What are the attachments of the carotid sheaths?
Attach sueriorly to the base of the skull
Blend inferiory with the mediastinal fascia
Where is the pretracheal fascia?
Anteriorly and deep to the investing fascia
What is enclosed within the pretracheal fascia?
Strap muscles Trachea recurrent laryngeal nerves Thyroid gland oesophagus
Where is the retropharyngeal space?
Between the pretracheal and prevertebral fascia
What are the attachments of the sterncleidomastoid muscles?
Sternal head - manubrium of sternum
Clavicular head - medial end of the clavicle
both heads pass superiorly to attach to the mastoid process of the temporal bone
What is the attachment of the descending part of trapezius?
Attaches inferiorly at the spine of the scapula ad the lateral end of the clavicle
What does the anterior jugular vein drain into?
External jugular vein
Describe the blood supply to the thyroid gland
Right and left superior and inferior thyroid arteries
What is the venous drainage of the thyroid gland?
Right and left superior middle and inferior thyroid veins
What is the lymphatic drainage of the thyroid gland?
Right and left superior and inferior deep cervical nodes
Name the tracheal lymph nodes.
Pretracheal lymph nodes
Paratracheal lymph nodes
Name the 4 strap muscles.
Omohyoid
Thyrohyiod
Sternothyroid
Sternohyoid
Which strap muscle has a fascial sling associated with it?
Omohyoid
Where does the recurrent laryngeal nerve run?
Asceds in the groove between the trachea anteriorly and the oesophagus posteriorly
The recurrent laryngeal nerve supplies somatic motor to what?
Most of the skeletal muscles that move the vocal cords (intrinsic muscles of the larynx)
What happens if there is reurrent laryngeal nerve injury?
Paralysis of the vocal cords
What does unilateral recurrent laryngeal nerve injury result in?
hoarseness or weakness of the voice and a weak cough
What does bilateral recurrent laryngeal nerve injury result in?
Aphonia (inability to produce sound) and inability to close the rima glottidis to prevent aspiration or to produce a good cough
