Mediastinum and Thorax Anatomy

Question 1

Which are the most important paired cartilages in the upper airway?

Answer 1

Arytenoids

Question 2

What are the single cartilages?

Answer 2

• epiglottis
• thyroid cartilage
• cricoid cartilage

Question 3

How is the position of the larynx identified?

Answer 3

by laryngeal prominence

= Adam’s apple

Question 4

What important endocrine gland covers the larynx anteriolaterally?

Answer 4

thyroid

Question 5

What part of the GI tract covers the larynx posteriorly?

Answer 5

laryngopharynx

Question 6

What membrane fills the gap between the hyoid and the thyroid cartilage of the larynx?

Answer 6

cricothyroid membrane

Question 7

What are the important anatomical structures in the larynx?

Answer 7

C2: angle of mandible 
C3: hyoid bone
C4: thyroid notch
C6: cricoid cartilage, start of oesophagus
C7: vertebrae prominens
T2/3: upper manubrium border 
T3-4: manubrium (overlies aortic arch)
T5-8: sternum (overlies heart)

Question 8

Which muscles cause movement of the thyroid and arytenoid cartilages?

Answer 8

intrinsic laryngeal muscles

Question 9

What is the main function of the intrinsic laryngeal muscles?

Answer 9

change position and tension of vocal cords

Question 10

What is the portion of the pharynx to the larynx?

Answer 10

pharynx is posterior to larynx

Question 11

What is the significance of the piriform fossa?

Answer 11

important for speech

food can also get trapped here

Question 12

What structure exists to close off the entrance to the tracheobronchial tree?

Answer 12

epiglottis

Question 13

What level does the trachea bifurcate at?

Answer 13

T4-5

Question 14

What is the importance of the trachealis muscle?

Answer 14

smooth muscle: bridges gap between free ends of C-shaped cartilage

function: contract trachea, air is expelled with greater force e.g. during coughing

Question 15

How are the lungs attached in the pleural cavity?

Answer 15

each lung is suspended freely in the pleura

attached at hilum only

Question 16

How does the shape of the inferior margins differ to that of the posterior border of the lungs?

Answer 16

INFERIOR: sharp

POSTERIOR: rounded

Question 17

What is the mediastinum?

Answer 17

central region of thoracic cavity

located between 2 laterally placed pleural cavities

Question 18

What is the mediastinum divided into? What separates them?

Answer 18

superior
inferior parts

separated by transverse plane: extends from manubriosternal junction to the intervertebral disc at T4-5

Question 19

What can damage to the phrenic nerve cause?

Answer 19

Hiccup reflex: phrenic nerve irritation, causes diaphragm to contract abnormally

Question 20

What can phrenic nerve damage cause?

Answer 20

diaphragm paralysis

prevents patient from being able to regulate their own breathing independently

Question 21

What is the course of the RIGHT recurrent laryngeal nerve?

Answer 21

loops underneath innominate artery

then ascends in lateral groove (between trachea - oesophagus) to enter inferior portion of larynx

Question 22

What is a serous membrane?

Answer 22

any of the smooth moist delicate membranes, such as the pleura or peritoneum, that line the closed cavities of the body and secrete a watery exudate.

Question 23

When is the pleural cavity located?

Answer 23

between the parietal and visceral layers
kept moist by a small volume of pleural fluid
kept at sub-atmospheric pressure

Question 24

What is the visceral pleura attached to?

Answer 24

directly to the lungs

continuous with the mediastinal pleura at lung root

Question 25

Which nerves innervate the parietal pleura?

Answer 25

intercostal nerves

phrenic nerves

Question 26

What is the visceral pleura innervated by?

Answer 26

autonomic nervous system

Question 27

What structure passes though the loop of the right Crus?

Answer 27

Oesophageal hiatus (T10)

• oesophagus
• vagus nerve