The thyroid gland is closely related to which anatomical structures in the anterior neck?
Usually, the thyroid gland consists of which three parts?
- Right lateral lobe
- Left lateral lobe
What is the isthmus of the thyroid gland?
The connection between the right and left lateral lobes
The lateral lobes of the thyroid gland attach to what?
Lateral aspects of thyroid and cricoid cartilages
The isthmus lies anterior to the ____ and ____ cartilages of the trachea
The isthmus lies anterior to the 2nd and 3rd cartilages of the trachea
Where are the four parathyroid glands located?
Posterior surfaces of the thyroid gland's lateral lobes
What is one of the most common anatomical variations of the thyroid gland?
Usually the pyramidal lobe originates from the _______ lateral lobe
Usually the pyramidal lobe originates from the left lateral lobe
How does the thyroid gland begin its development?
A midline epithelial proliferation at the junction between the anaterior and posterior aspects of the tongue
The thyroid gland will migrate inferiorly whist still being attached to the tongue via what?
In which week of development will the thyroid gland reach its final postition?
What are the platysma?
Broad sheet-like superficial muscles that overlap the sternocleidomastoid and sit in the subcutaneous tissue in the neck
What is the nerve supply of the platysma muscles?
Facial nerve (CN VII)
How many fascial compartments are there in the neck?
What are the fascial compartments in the neck?
- Prevertebral deep fascia
- Investing deep fascia
- Carotid sheaths
- Pretracheal deep fascia
What is the location of the prevertebral deep fascia?
Deep to the investing fascia
Located most posteriorly in the neck
What is contained within the investing fascia?
- All other neck fascial compartments
What is carried within the carotid sheaths in the neck?
- Vagus nerves
- Carotid arteries (common then internal)
- Internal jugular veins
- Deep cervical lymph nodes
Where is the pretracheal fascia located and what does it enclose?
Most anteriorly within the enclosure of the investing fascia
- Thyroid gland
- Strap muscles
- Recurrent laryngeal nerves
Which nerve supplies the sternocleidomastoid and trapezius?
Spinal accessory nerve (CN XI)
The external jugular vein runs within the __________ _______ and drains into the _____________ _____
The external jugular vein runs within the superficial fascia and drains into the subclavian vein
Where does the anterior jugular vein run and where does it drain?
External jugular vein
The sternocleidomastoid is enclosed within what?
The sternocleidomastoid has two heads, what are they and where do they both insert?
Sternal head - manubrium of the sternum
Clavicular head - medial end of the clavicle
What is the origin of the sternocleidomastoid?
Mastoid process of the temporal bone
The carotid sheaths are located _____________ either side of the __________ ________
The carotid sheaths are located anterolaterally either side of the thyroid gland
Where do the carotid sheaths attach to the skull?
Base of skull
(around jugular foramen and entrance to carotid canal)
Where does the carotid sheath attach inferiorly?
Blends with mediastinal fascia
Where is the vagus nerve located in the neck?
(between the common carotid artery and the internal jugular vein)
What is the arterial supply of the thyroid gland?