Anatomy of the Thyroid Gland Flashcards Preview

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Flashcards in Anatomy of the Thyroid Gland Deck (52)
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1
Q

The thyroid gland is closely related to which anatomical structures in the anterior neck?

A
  1. Larynx
  2. Trachea
2
Q

Usually, the thyroid gland consists of which three parts?

A
  1. Right lateral lobe
  2. Left lateral lobe
  3. Isthmus
3
Q

What is the isthmus of the thyroid gland?

A

The connection between the right and left lateral lobes

4
Q

The lateral lobes of the thyroid gland attach to what?

A

Lateral aspects of thyroid and cricoid cartilages

5
Q

The isthmus lies anterior to the ____ and ____ cartilages of the trachea

A

The isthmus lies anterior to the 2nd and 3rd cartilages of the trachea

6
Q

Where are the four parathyroid glands located?

A

Posterior surfaces of the thyroid gland’s lateral lobes

7
Q

What is one of the most common anatomical variations of the thyroid gland?

A

Pyramidal lobe

8
Q

Usually the pyramidal lobe originates from the _______ lateral lobe

A

Usually the pyramidal lobe originates from the left lateral lobe

9
Q

How does the thyroid gland begin its development?

A

A midline epithelial proliferation at the junction between the anaterior and posterior aspects of the tongue

10
Q

The thyroid gland will migrate inferiorly whist still being attached to the tongue via what?

A

Thyroglossal duct

11
Q

In which week of development will the thyroid gland reach its final postition?

A

7th

12
Q

What are the platysma?

A

Broad sheet-like superficial muscles that overlap the sternocleidomastoid and sit in the subcutaneous tissue in the neck

13
Q

What is the nerve supply of the platysma muscles?

A

Facial nerve (CN VII)

14
Q

How many fascial compartments are there in the neck?

A

4

15
Q

What are the fascial compartments in the neck?

A
  1. Prevertebral deep fascia
  2. Investing deep fascia
  3. Carotid sheaths
  4. Pretracheal deep fascia
16
Q

What is the location of the prevertebral deep fascia?

A

Deep to the investing fascia

Located most posteriorly in the neck

17
Q

What is contained within the investing fascia?

A
  1. All other neck fascial compartments
  2. Trapezius
  3. Sternocleidomastoid
18
Q

What is carried within the carotid sheaths in the neck?

A
  1. Vagus nerves
  2. Carotid arteries (common then internal)
  3. Internal jugular veins
  4. Deep cervical lymph nodes
19
Q

Where is the pretracheal fascia located and what does it enclose?

A

Most anteriorly within the enclosure of the investing fascia

Encloses:

  1. Oesophagus
  2. Trachea
  3. Thyroid gland
  4. Strap muscles
  5. Recurrent laryngeal nerves
20
Q

Which nerve supplies the sternocleidomastoid and trapezius?

A

Spinal accessory nerve (CN XI)

21
Q

The external jugular vein runs within the __________ _______ and drains into the _____________ _____

A

The external jugular vein runs within the superficial fascia and drains into the subclavian vein

22
Q

Where does the anterior jugular vein run and where does it drain?

A

Superficial fascia

External jugular vein

23
Q

The sternocleidomastoid is enclosed within what?

A

Investing fascia

24
Q

The sternocleidomastoid has two heads, what are they and where do they both insert?

A
  1. Sternal head - manubrium of the sternum
  2. Clavicular head - medial end of the clavicle
25
Q

What is the origin of the sternocleidomastoid?

A

Mastoid process of the temporal bone

26
Q

The carotid sheaths are located _____________ either side of the __________ ________

A

The carotid sheaths are located anterolaterally either side of the thyroid gland

27
Q

Where do the carotid sheaths attach to the skull?

A

Base of skull

(around jugular foramen and entrance to carotid canal)

28
Q

Where does the carotid sheath attach inferiorly?

A

Blends with mediastinal fascia

29
Q

Where is the vagus nerve located in the neck?

A

Carotid sheath

(between the common carotid artery and the internal jugular vein)

30
Q

What is the arterial supply of the thyroid gland?

A
  1. Superior thyroid arteries
  2. Inferior thyroid arteries
31
Q

The inferior thyroid arteries are branches of which arteries?

A

Subclavian arteries

32
Q

The superior thyroid arteries are branches of which arteries?

A

External carotid arteries

33
Q

Which artery is an anatomical variant that may supply blood to the thyroid gland and where does it originate?

A

Thyroid ima artery

Usually brachiocephalic

34
Q

What is the venous drainage of the thyroid gland?

A

Superior, middle and inferior thyroid veins

35
Q

Where do the superior and middle thyroid veins drain?

A

Internal jugular veins

36
Q

Where does the inferior thyroid vein drain?

A

Left brachiocephalic vein

37
Q

Where do the internal jugular veins drain?

A

Right and left brachiocepalic veins

38
Q

What is the lymphatic drainage of the thyroid gland

a) Superiorly
b) Inferiorly

A

a) Superior deep cervical lymph nodes
b) Inferior deep cervical lymph nodes

39
Q

What are the types of lymph nodes surrounding the trachea?

A
  1. Pretracheal
  2. Paratracheal
40
Q

How is lymph returned to the circulation

a) On the right side
b) On the left side

A

a) Via right lymphatic duct to right venous angle
b) Via thoracic duct to left venous angle

41
Q

The vagus nerves branch from the ________ _________ and exit the skull via the _________ __________ then descend within the ___________ _________

A

The vagus nerves branch from the medulla oblongata and exit the skull via the jugular foramen then descend within the carotid sheaths

42
Q

Within the chest the right vagus nerve will be found _______ to the trachea

A

Within the chest the right vagus nerve will be found lateral to the trachea

43
Q

Within the chest, the left vagus nerve will be found to which side of the aortic arch?

A

Left

44
Q

Both vagus nerve travel ________ to the lung hila

A

Both vagus nerve travel posterior to the lung hila

45
Q

Both vagus nerves pass into the abdomen with the ___________

A

Both vagus nerves pass into the abdomen with the oesophagus

46
Q

The right recurrent larngeal nerve recurs under what?

A

Right subclavian artery

47
Q

The left recurrent laryngeal nerve recurs under what?

A

Arch of aorta

48
Q

What are the four strap muscles?

A
  1. Sternohyoid
  2. Sternothyroid
  3. Thyrohyoid
  4. Omohyoid
49
Q

How can the omohyoid muscle be distinguished?

A
  1. Tendinous section within the middle segment
  2. Fascial sling attaches it to clavcle preventing bowstringing
50
Q

If structures are damaged iatrogenically, what does this mean?

A

They are damaged by a clinician

51
Q

Recurent larngeal nerve injury results in what?

A

Paralysis of the vocal cords

  1. Unilaterally - weakvoice and cough, hoarse voice
  2. Bilaterally - aphonia (cannot make sound), inability to close rima glottidis, cannot produce good cough
52
Q

With bilateral recurrent laryngeal nerve injury, what is the risk of being unable to close the rima glottidis?

A

Cannot prevent aspiration