Clinical anatomy of the thorax

Question 1

What is quinsy?

Answer 1

Inflammation of the throat, more specifically abscesses in the region of the tonsils

Question 2

What are the roles of the nasal cavity?

Answer 2

1. warms and dehumidifies inhaled air
2. removes and traps pathogens from inspired air
3. sense of smell
4. drains paranasal sinuses and lacrimal ducts

Question 3

What makes up the nasal cavity?

Answer 3

Septal cartilage
Ethmoid (superior and middle conchae)
Vomer

Question 4

State where each of the nasal sinuses drain to.

Answer 4

• Frontal sinus drains to semilunar hiatus
• Anterior ethmoid sinus drains to semilunar hiatus
• Middle ethmoid sinus drains to the ethmoid bulla
• Posterior ethmoid sinus drains to the superior meatus
• Maxillary sinus drains to the semilunar hiatus

Question 5

Which muscles are the circular and longitudinal muscles of the pharynx?

Answer 5

Circular: superior, middle and inferior constrictor muscles
Longitudinal: stylopharyngeus, palatopharyngeus, salpingopharyngeus

Question 6

What are the roles of the larynx?

Answer 6

Phonation

Protection of lower airways

Question 7

Which arteries supply the larynx and where do these arteries branch from?

Answer 7

Superior laryngeal - branch of external carotid artery

Inferior laryngeal - branch of the thyrocervical trunk

Question 8

State the names of the unpaired and paired cartilages that make up the larynx.

Answer 8

Unpaired:

1. epiglottis
2. thyroid
3. cricoid

Paired:

1. arytenoid
2. corniculate
3. cuneiform

Question 9

Name the ligaments of the larynx and their attachment points.

Answer 9

1. Thyrohyoid: hyoid bone –> thyroid cartilage
2. Cricothyroid: thyroid –> cricoid
3. Cricotracheal: cricoid –> trachea

Question 10

Which muscles in the larynx are responsible for phonation, and which are responsible for pitch?

Answer 10

Phonation:

1. arytenoid (transverse + oblique)
2. cricoarytenoid (lateral + posterior)
3. thyroarytenoid

Pitch:
Cricothyroid

Question 11

Name the suprahyoid and infrahyoid muscles of the larynx.

Answer 11

Suprahyoid:

• mylohyoid
• stylohyoid
• digastric (ant and post)
• geniohyoid

Infrahyoid:

• sternohyoid
• omohyoid (sup + inf)
• sternothyroid
• thyrohyoid

Question 12

Describe the motor and sensory innervation to the larynx.

Answer 12

• Internal laryngeal nerve: SENSORY innervation to area ABOVE vocal cords
• External laryngeal nerve: MOTOR to cricothyroid –> pitch
• Recurrent laryngeal nerve: MOTOR to all intrinsic muscles responsible for phonation
  also SENSORY to area BELOW the vocal cords

Question 13

How would a lesion to the recurrent laryngeal nerve present and why?

Answer 13

Lesion to recurrent laryngeal will cause vocal cord paralysis (inability to abduct laterally)
Present as hoarseness, aphonia and stridor

Question 14

How would a lesion to the external laryngeal nerve present and why?

Answer 14

Cricothyroid paralysis (preventing higher pitched phonation)
Present as weak voice, low pitch, easily tires and reduced range

Question 15

What are the branches of the external carotid artery?

Answer 15

1. superficial thyroid
2. ascending pharyngeal
3. lingual
4. facial
5. occipital
6. posterior auricular
7. maxillary
8. superifical temporal

Question 16

How is an emergency cricothyroidotomy performed?

Answer 16

1. Palpate laryngeal prominences of thyroid cartilage
2. work inferior to palpate the cricoid cartilage to ascertain thyroid ligament
3. make vertical incision from mid thyroid cartilage to superior aspect of cricoid cartilage
4. puncture through cricothyroid membrane with horizontal scalpel
5. insert airway