6: Anatomy of the thyroid gland

Question 1

Which parts of the respiratory tract is the thyroid gland closely associated with?

Answer 1

Larynx

Trachea

Question 2

Which general part of the body is the thyroid gland found in?

Answer 2

Neck

Question 3

What are the three parts of the thyroid gland found in all people?

Answer 3

Isthmus

Left and right lateral lobes

Question 4

What are the three cartilages found in the anterior neck?

Answer 4

Thyroid cartilage

Cricoid cartilage

Trachea

Question 5

The isthmus lies anterior to which tracheal “rings”?

Answer 5

2nd and 3rd

Question 6

An enlarged thyroid will move ___ then ___ during swallowing.

(inferiorly , superiorly)

Answer 6

superiorly then inferiorly

Question 7

What is an abnormal swelling of the thyroid gland called?

Answer 7

Goitre

Question 8

Which cartilage is found in the posterior larynx?

Answer 8

Arytenoid cartilages

Question 9

Where exactly are the parathyroid glands found?

Answer 9

Posterior surface of lateral lobes

Question 10

What is a common variant structure of the thyroid gland?

Where is it found?

Which bone may it connect to?

Answer 10

Pyramidal lobe

Anterior surface of larynx, midline extending upwards from isthmus to thyroid cartilage

Hyoid bone

Question 11

Where generally does the thyroid gland originate during embryological development?

Answer 11

Tongue

Question 12

During development, the thyroid gland is found between the __ 2/3rds and __ 1/3rd of tongue.

What is this junction called?

What hole is found in the junction?

Answer 12

anterior 2/3rds, posterior 1/3rd

terminal sulcus

foramen caecum

Question 13

During development, the thyroid gland migrates inferiorly through what?

Answer 13

Thyroglossal duct

Question 14

What can form if remnants of thyroid tissue remain in the thyroglossal duct?

Answer 14

Pyramidal lobe

Nodules

Question 15

Just as in the upper and lower limbs, the neck has ___ containing different structures.

Answer 15

compartments

Question 16

What superficial muscles are found in the outer layer of neck skin?

Answer 16

Platysma

Question 17

Platysma are muscles of ___ ___ and are therefore innervated by CN __.

Answer 17

facial expression

CN VII - facial nerve

Question 18

Apart from the platysma muscles, what are two other muscles of facial expression?

Answer 18

Frontalis

Orbicularis oculi

Orbicularis oris

there are literally millions

Question 19

The neck has four fascial compartments - what are they called?

Answer 19

Investing fascia

Prevertebral fascia

Carotid sheathes

Pretracheal fascia

Question 20

The investing fascia is most superficial and surrounds all the other fascial compartments of the neck.

Which two pairs of muscles are found in the investing fascia?

Answer 20

Trapezius

Sternocleidomastoid

Question 21

What is found in the prevertebral fascia?

Answer 21

Postural neck muscles

Cervical vertebrae

Question 22

Which structures are found in the carotid sheathes?

Answer 22

Vagus nerves

Common then Internal carotid arteries

Internal jugular veins

Deep cervical lymph nodes

Question 23

What five structures are found within the pretracheal fascia?

Answer 23

Trachea

Oesophagus

Thyroid

Strap muscles

Recurrent laryngeal nerves (branches of the vagus nerve)

Question 24

Which nerve supplies the muscles of the investing fascia (trapezius and sternocleidomastoid)?

Answer 24

CN XI - spinal accessory nerve

Question 25

The SCM has two heads - what are they called?

Answer 25

**Sternal head** **Clavicular head**

Question 26

Which part of the sternum does the SCM attach to?

Answer 26

**Manubrium**

Question 27

The clavicular head of the SCM attaches to the (medial / lateral) end of the clavicle.

Answer 27

**medial**

Question 28

What is the superior attachment of the SCM?

Answer 28

**Mastoid process** of the **temporal bone**

Question 29

What does the **trapezius** attach to inferiorly?

Answer 29

**Spine of scapula** **Lateral end of clavicle**

Question 30

What are the **three** jugular veins found in the neck?

Answer 30

**External** **Internal** **Anterior**

Question 31

The external jugular vein drains into the ___ \_\_\_.

Answer 31

**brachiocephalic vein**

Question 32

The internal jugular vein drains into the ___ \_\_\_.

Answer 32

**brachiocephalic vein**

Question 33

The anterior jugular vein drains into the __ \_\_ \_\_.

Answer 33

**external jugular vein**

Question 34

The **superior thyroid artery** arises from the ___ \_\_\_ \_\_\_.

Answer 34

**external carotid artery**

Question 35

The **inferior thyroid artery** branches from the ___ \_\_\_.

Answer 35

**subclavian artery**

Question 36

The **superior, middle** and **inferior thyroid veins** are branches of which vein?

Answer 36

**Internal jugular vein**

Question 37

What do the superior and middle thyroid veins drain into?

Answer 37

**Internal jugular vein**

Question 38

What do the **inferior thyroid veins** drain into?

Answer 38

**LEFT brachiocephalic vein**

Question 39

In the carotid sheathes, the internal jugular veins are lined with lymph nodes. Which two groups of lymph nodes in particular?

Answer 39

**Superior deep cervical lymph nodes** **Inferior deep cervical lymph nodes**

Question 40

What two types of lymph node are found on the trachea?

Answer 40

**Pretracheal** (midline) **Paratracheal** (lateral)

Question 41

How does lymph drain into the venous circulation on the LEFT?

Answer 41

**Thoracic duct** \> **Left venous angle**

Question 42

How does lymph drain into the venous circulation on the RIGHT?

Answer 42

**Right lymphatic duct** \> **Right venous angle**

Question 43

Through which holes in the posterior cranial fossa do the vagus nerves exit?

Answer 43

**Jugular foraminae**

Question 44

The left vagus nerve is found **(medial / lateral)** to the trachea.

Answer 44

**lateral**

Question 45

The right vagus nerve is found **(medial / lateral)** to the arch of the aorta.

Answer 45

**lateral**

Question 46

Do the vagus nerves run **anterior** or **posterior** to the lung hila?

Answer 46

**posterior**

Question 47

Which structure in the thorax do the vagus nerves lie on the surface of?

Answer 47

**Oesophagus**

Question 48

Through which hole in the diaphragm do the vagus nerves pass?

Answer 48

**Oesophageal hiatus**

Question 49

What branches of the vagus nerve supply the laryngeal muscles?

Answer 49

**Recurrent laryngeal nerves** Apart from cricothyroid, which is supplied by **External laryngeal nerve** (branch of Superior)

Question 50

What surface of the thyroid gland do the recurrent laryngeal nerves run on?

Answer 50

**Posterior surface**

Question 51

The **left recurrent laryngeal nerve** hooks under what before travelling back up into the neck?

Answer 51

Arch of the aorta

Question 52

The **right** **recurrent laryngeal nerve** hooks under what before travelling back up into the neck?

Answer 52

**Right subclavian artery**

Question 53

What are the important attachments for the **strap muscles** of the neck?

Answer 53

**Hyoid bone** **Thyroid cartilage** **Manubrium of sternum** **Clavicle**

Question 54

The strap muscles are found in which fascial layer of the neck?

Answer 54

**Pretracheal fascia**

Question 55

Are the strap muscles **intrinsic** or **extrinsic** muscles of the larynx?

Answer 55

**Extrinsic** not found IN the larynx but help to move it

Question 56

What are the four strap muscles?

Answer 56

**Omohyoid muscle** **Sternohyoid muscle** **Sternothyroid muscle** **Thyrohyoid muscle**

Question 57

The **omohyoid muscle** joins the clavicle to the hyoid bone. What stops "bowstringing" which would pull the neck to one side?

Answer 57

**Fascial sling on medial end of clavicle which pulls it downwards**

Question 58

What are the three important parts of the omohyoid muscle?

Answer 58

**Superior belly** **Intermediate tendon** **Inferior belly**

Question 59

What do the recurrent laryngeal nerves supply?

Answer 59

**Intrinsic muscles of the larynx**

Question 60

The recurrent laryngeal nerves give a (motor / sensory) supply to the intrinsic muscles of the larynx.

Answer 60

**motor**

Question 61

What is Berry's ligament?

Answer 61

Attachment of posterior surface of thyroid to trachea

Question 62

Recurrent laryngeal nerve injury results in ___ of the ___ \_\_\_.

Answer 62

**paralysis** **vocal cords**

Question 63

What is the opening between the vocal cords called? What structure is it found inferior to?

Answer 63

**Rima glottidis** **Epiglottis**