Anatomy of the Thyroid Gland Flashcards Preview

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Flashcards in Anatomy of the Thyroid Gland Deck (61):
1

At what vertebral level does the larynx become the trachea

C6

2

What 2 structures is the thyroid gland closely related to in the anterior neck

The larynx and the trachea

3

What does the thyroid gland usually consist of

2 lateral lobes (right and left) and an isthmus

4

What is the isthmus

A narrow connecting band

5

What do the lobes of the thyroid gland attach to

The lateral aspects of the thyroid and cricoid cartilages and to the trachea

6

What direction will the thyroid gland move when we swallow

Same as the larynx and the trachea
It will move superiorly then inferiorly

7

Where are the 4 parathyroid glands located

Not the posterior surfaces of the thyroid gland's lateral lobes

8

What cartilage is located superiorly to the cricoid cartilage

The arytenoid cartilage

9

Where does the pyramidal lobe most commonly originate from

The left lateral lobe of the thyroid gland

10

Where doe most pyramidal lobes superiorly attach to

the thyroid cartilage

11

Some pyramidal lobes may extend as far superiorly as where?

The hyoid bone

12

Where does the thyroid gland begin its development

As a midline epithelial proliferation at the junction between the anterior 2/3rd and the posterior 1/3 of the tongue

13

Where does the gland migrate to

Migrates inferiorly whilst remaining attached to the tongue to the thryoglossbal duct

14

When does the thyroid gland reach its final position

7th week of development

15

Where might the pyramidal bone be found

Anywhere along the migratory path of the thyroid gland
It is an ectopic thyroid gland tissue

16

What encapsulates the trachea, the oesophagus and the thyroid gland

A layer of deep neck fascia - pre tracheal fascia

17

What muscle can be found in the superficial fascia

The platysma muscle - muscle of facial expression

18

Where nerve supplies the platysma muscles

cranial nerve VII (facial nerve)

19

Where does the platysma muscle lie

It extends for the lower border of the mandible to the lower border of the neck

20

Name the 4 fascial compartments of the neck

Prevertebral (deep) fascia
Investing (deep) fascia
The 2 carotid sheaths
Pretracheal (deep) fascia

21

What deep fascia layer is the most superficial

Investing

22

What is contained within the investing fascia

All other neck fascial compartments
encloses 2 pairs of muscles: trapezius and the sternocleidomastoid

23

What fascia is deep to the investing fascia

Prevertebral fascia, the pre tracheal fascia and the 2 carotid sheaths

24

What is contained within the prevertebral fascia

Encloses the cervical vertebrae and the postural neck muscles

25

What is enclosed by the carotid sheaths

Internal jugular veins
carotid arteries
the vagus nerves
the deep cervical lymph nodes

26

What are the strap muscles responsible for

Depressing the laryngeal cartilage when speaking and swallowing

27

What is the space between the prevertebral and the pre tracheal fascia called and why is this important

Retropharyngeal space - if infection develops, it will spread rapidly through this space

28

where does the sternocleidomastoid attach

Sternal head - manubrium of the sternum
clavicular head - medial end of the clavicle
Both heads pass superiorly to attach to the mastoid process of the temporal bone

29

Describe the anterior jugular vein

It is superficial vein in the superficial fascia which drains into he external jugular vein

30

Describe the external jugular vein

A superficial vein in the superficial fascia which drains in to the subclavian vein

31

what cranial nerve supplies the sternocleidomastoid and the trapezius

Cranial nerve XI - spinal accessory nerve

32

Where does the carotid sheaths lie

Deep to the investing fascia and located anterolaterally in the neck either side of the thyroid gland

33

Describe the structure of the carotid sheaths

Bilatera tubes of deep fascia which attach superiorly to the base of the skull. They run down the neck into the superior part of the thorax and the fascia will blend in with the mediastinal fascia

34

What is enclosed within each carotid sheath

The internal jugular vein
The common, then the internal carotid arteries
The vagus nerve
the deep cervical lymph nodes

35

Where do both the left and right inferior thyroid arteries branch from

The subclavian artery

36

Describe the venous drainage of the thyroid and parathyroid glands

Superior, middle and inferior

37

What drains into the internal jugular vein

The superior and middle thyroid veins

38

What drains into the left brachiocephalic vein

Both the right and left inferior veins

39

Where is the location of the venous angle

Between the internal jugular vein and the subclavian vein

40

Where do the paratracheal nodes sit

Either side of the trachea

41

What 2 somatic branches does the vagus nerve give rise to in the larynx

Superior laryngeal nerve and the right recurrent laryngeal nerve

42

Describe the route of the right recurrent laryngeal nerve

It is a branch of the vagus nerve that hooks up underrate the right subclavian artery to then ascend back up towards the larynx

43

Describe the route of the right vagus nerve

Lateral aspect of the trachea - it then passes posteriorly to the root of the lung and follow onto the surface of the oesophagus

44

Where does the phrenic nerve lie

Anteriorly to the root of the lung

45

Describe the route of the vagus nerve on the left hand side

It follows the arch of the aorta and it gives off the left recurrent laryngeal nerve - it hooks underneath the arch of the aorta to ascend back up towards the larynx

46

What are the names of the 4 strap muscles

Sternohyoid
Thyrohyoid
Omohyoid
Sternothyroid

47

What 1 of the 4 strap muscles has 2 bellies

The omohyoid - superior and inferior bellies

48

What causes the omohyoid muscle to change direction

A small tendon that grips the mid portion of the muscle

49

Where does the thyrohyoid muscle lie

The thyroid to the hyoid bone

50

Where does the sternohyoid muscle lie

Sternum to the hyoid bone

51

Where does the sternothroid muscle like

the sternum to the thyroid bone

52

Where does the omohyoid muscle lie

Extends out towards the shoulder and attaches to the scapula to the hyoid bone

53

What is the superior border of the manubrium

The jugular notch

54

The external jugular vein cross what

The muscle belly of the sternocleidomastoid

55

What forms the borders of anterior triangle of the neck

The laryngeal prominence of the thyroid cartilage,
The jugular notch
The sternal head border
The angle of the mandible and the inferior border of the mandible

56

What forms the borders of the posterior triangle of the neck

Trapezius
The clavicular head border of the sternocleidomastoid and the clavicle

57

How is a classical thyroidectomy performed

An incision through the skin and platysma just above the jugular notch and superior to the clavicle along langers lines

58

What 2 structures does the recurrent laryngeal nerve lie between

In a groove between the trachea and the oesophagus

59

What happens if a recurrent laryngeal nerve is damaged

Results in hoarse voice or losing the voice altogether

60

What happens if both recurrent laryngeals are damaged bilaterally

Aphonia (inability to produce sound and also the inability to close the rim glottidis to prevent aspiration or produce a good cough - very dangerous situation

61

What does the right recurrent laryngeal nerve provide

Somatic motor supply to most of the skeletal muscles that move the right vocal cord