Anatomy of the Thyroid Gland

Question 1

What is the thryoid usually made up of?

Answer 1

2 lateral lobes and an isthmus

Question 2

Where do the thyroid lobes attach?

Answer 2

Lateral aspects of the thyroid and cricoid cartilages and to the trachea

Question 3

Where does the isthmus lie?

Answer 3

Anterior to the 2nd and 3rd trachael cartilages

Question 4

If the thyroid gland is enlarged or there is a lump, which direction will it move?

Answer 4

Superiorly then inferiorly with the larynx during swallowing

Question 5

How many and where are the parathryiod glands located?

Answer 5

4 - The posterior surface of the thyroid glands lateral lobes

Question 6

What do 22-55% of the population have with regard to the anatomy of the thyroid gland?

Answer 6

A pyrimidal lobe

Question 7

What and where are the platysma muscles?

Answer 7

Belong to the group of “muscles of facial expression” and are locted immediately deep to the skin, within the superficial fascia of the neck

Question 8

What nerve supplies the patysma muscles?

Answer 8

Cranial nerve VII (facial nerve)

Question 9

Name the 4 fascial compartements of the neck?

Answer 9

Investing (deep) fascia
Carotid sheaths
prevertebral fascia
Pretracheal fasica

Question 10

Where is and what is the purpose of the investing fascia?

Answer 10

Foud deep to the superficial fascia and encloses all other neck compartments and the trapezius and sternocleidomastoid muscles

Question 11

Where is the prevertebral fascia found and what does it enclose?

Answer 11

Posteriorly and deep to the investing fascia

encloses the cervical vertebrae and the postural neck muscles

Question 12

Where are the 2 carotid sheaths?

Answer 12

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

Question 13

What is contained within the carotid sheaths?

Answer 13

• internal jugular veins
• vagus nerves
• carotid arteries
• deep cervical lymph nodes

Question 14

What are the attachments of the carotid sheaths?

Answer 14

Attach sueriorly to the base of the skull

Blend inferiory with the mediastinal fascia

Question 15

Where is the pretracheal fascia?

Answer 15

Anteriorly and deep to the investing fascia

Question 16

What is enclosed within the pretracheal fascia?

Answer 16

Strap muscles 
Trachea 
recurrent laryngeal nerves 
Thyroid gland
oesophagus

Question 17

Where is the retropharyngeal space?

Answer 17

Between the pretracheal and prevertebral fascia

Question 18

What are the attachments of the sterncleidomastoid muscles?

Answer 18

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

Question 19

What is the attachment of the descending part of trapezius?

Answer 19

Attaches inferiorly at the spine of the scapula ad the lateral end of the clavicle

Question 20

What does the anterior jugular vein drain into?

Answer 20

External jugular vein

Question 21

Describe the blood supply to the thyroid gland

Answer 21

Right and left superior and inferior thyroid arteries

Question 22

What is the venous drainage of the thyroid gland?

Answer 22

Right and left superior middle and inferior thyroid veins

Question 23

What is the lymphatic drainage of the thyroid gland?

Answer 23

Right and left superior and inferior deep cervical nodes

Question 24

Name the tracheal lymph nodes.

Answer 24

Pretracheal lymph nodes

Paratracheal lymph nodes

Question 25

Name the 4 strap muscles.

Answer 25

Omohyoid
Thyrohyiod
Sternothyroid
Sternohyoid

Question 26

Which strap muscle has a fascial sling associated with it?

Answer 26

Omohyoid

Question 27

Where does the recurrent laryngeal nerve run?

Answer 27

Asceds in the groove between the trachea anteriorly and the oesophagus posteriorly

Question 28

The recurrent laryngeal nerve supplies somatic motor to what?

Answer 28

Most of the skeletal muscles that move the vocal cords (intrinsic muscles of the larynx)

Question 29

What happens if there is reurrent laryngeal nerve injury?

Answer 29

Paralysis of the vocal cords

Question 30

What does unilateral recurrent laryngeal nerve injury result in?

Answer 30

hoarseness or weakness of the voice and a weak cough

Question 31

What does bilateral recurrent laryngeal nerve injury result in?

Answer 31

Aphonia (inability to produce sound) and inability to close the rima glottidis to prevent aspiration or to produce a good cough