Session 11 & 12 Group Work

Question 1

What is the muscle which elevates the thyroid?

Answer 1

Levator glandulae thyroideae

Question 2

What does levator glandulae thyroideae connect the thyroid to?

Answer 2

The isthmus of the thyroid gland to the hyoid bone

Question 3

What is the role of the supra and infrahyoid during swallowing?

Answer 3

Suprahyoid - Lift the larynx to prevent influx of food into the airway
Infrahyoid - Stabilise the larynx by opposing actions of suprahyoids

Question 4

Why does the thyroid gland move during swallowing?

Answer 4

Part of pretracheal fascia forms sheath of thyroid. Superiorly attached to thyroid and cricoid cartilages, inferiorly posterior surface of pericardium.
When laryngeal skeleton ascends during swallowing, the thyroid gland moves as well

Question 5

Why is inferior thyroid artery torturous in structure?

Answer 5

Thyroid artery ascends a few centimetres every swallow, and so must drag arterial supply with it

Question 6

Why is C6 an important vertebral landmark? (4)

Answer 6

• Junction of larynx and trachea
• Site at which carotid can be compressed against carotid tubercle of C7
• Level at which vertebral artery enters transverse formamen in the 6th cervical verterbra
• Level of middle cervical ganglion

Question 7

Why may parathyroid gland be found within the thymus gland retrosternal position?

Answer 7

Two pairs of parathyropid gland develop from 3rd and 4th pharyngeal pouch. Abberant third may descend with thymus instead of thyroid tissue.

Question 8

What is the carotid sinus?

Answer 8

Slight dilation of the proximal part of internal carotid artery called carotid sinus.
Supplied by glossopharyngeal nerve through carotid sinus nerve.

Question 9

What is the function of carotid sinus massage?

Answer 9

Baroceptor, supraventricular tachycardia can be relieved by it.

Question 10

What is the carotid body?

Answer 10

Lies deep to medial side of bifurcation of common carotid. Chemoreceptor that monitors level of oxygen and CO2 in blood.

Question 11

What nerves may be damaged in carotid arteriorgram?

Answer 11

Sympathetic chain

Vagus

Question 12

What is a probable cause of neck swelling? (2)

Answer 12

Thyroglossal cyst

Lymph node

Question 13

Why woudl lymphadenopathy be concerning?

Answer 13

Cancerous growth may malignantly spread to lymph nodes

Question 14

What causes left vocal cord paralysis?

Answer 14

Unilateral damage to the left 
recurrent laryngeal nerve most 
probably during ligation of the inferior 
thyroid artery would most probably 
have led to its palsy in this case

Question 15

Give three possible causes of left vocal cord paralysis

Answer 15

Lung tumour
• Thyroid nodule
• Hyperplasia of thyroid tissue

Question 16

What is gag reflecx?

Answer 16

Also known as the pharyngeal reflex, is a reflex contraction of the back of the
throat, evoked by touching the soft palate.
It prevents something from entering
the throat except as part of normal swallowing and helps prevent choking.
Different people have different sensitivities to the gag reflex.
•
• Afferent Limb of Reflex
• Supplied by the glossopharyngeal nerve (cranial nerve IX), which inputs to the
• nucleus solitarius and the spinal trigeminal nucleus
•
• Efferent Limb of Reflex
• Supplied by the vagus nerve (cranial nerve X) from the nucleus ambiguus.
Absence
• of the gag reflex can be a symptom of a number of severe medical conditions,
such
• as damage to the glossopharyngeal nerve, the vagus nerve, or brain death

Question 17

Tonsilitis - which lymph node evident?

Answer 17

Jugulo-digastric

Question 18

What is a pharyngeal pouch?

Answer 18

Diverticulum of pharyngeal mucosa through a weakening between cricopharyngeus and thyropharyngeus muscles at top oesophagus. Makes up part of oesophageal sphincter

Question 19

Give two causes of pharyngeal pouch

Answer 19

Pressure generated by swallowing can over time result in out pouching of the underlying mucosa through weakness
Incoordination of swallowing reflex can result in more pressure on superior oesophageal sphincter

Question 20

Laryngeal skeleton can often appear bony. Why?

Answer 20

Laryngeal cartilage skelegton can ossify with age. In such cases, multiple plane imaging reccomended.