Lecture 20.1

Question 1

What is the Larynx?

Answer 1

• A tube lined by mucous membrane
• Skeleton is cartilaginous

Question 2

List the Cartilages of the Larynx

Answer 2

• Cricoid
• Thyroid
• 2 arytenoids
• Epiglottis

Question 3

Describe the Cricoid Cartilage

Answer 3

• Shaped like a signet ring with the wide part situated posteriorly
• Only complete cartilaginous ring in the respiratory system

Question 4

Describe the Thyroid Cartilage

Answer 4

Has 2 leaves - laminae
- Acute angle in male
- Obtuse angle in female

Question 5

What are the Laminae separated by?

Answer 5

V-shaped superior thyroid notch

Question 6

What does the Posterior border consist of?

Answer 6

Superior and inferior cornu (horn)

Question 7

Describe the Arytenoid Cartilage

Answer 7

3-sided pyramids, with a vocal process directed forwards and a muscular process directed laterally

Question 8

What type of joint is present and where?

Answer 8

Synovial joint present between the inferior horn and the side of the cricoid

Question 9

Describe the Epiglottis

Answer 9

• Large leaf-shaped piece of elastic cartilage attached to the posterior surface of the thyroid cartilage
• Projects upwards behind the hyoid bone

Question 10

Where is the Fibro-elastic tissue membrane?

Answer 10

Beneath the mucous membrane of the larynx

Question 11

What is the membrane divided into and by?

Answer 11

• Upper and lower parts
• By a horizontal interval termed ventricle

Question 12

What does the Free upper border of the Quadrangular membrane form?

Answer 12

Aryepiglottic fold

Question 13

What happens to the lower border of the Quadrangular membrane?

Answer 13

Thickened to form the vestibular ligament which raises the mucous membrane as the vestibular fold

Question 14

Where is the Cricothyroid Membrane?

Answer 14

• Lower part of the fibroelastic membrane
• Attached below the cricoid

Question 15

What is the Rima Glottidis?

Answer 15

The gap between the two vocal folds

Question 16

What is the origin of the Cricothyroid muscle?

Answer 16

Anterior aspect of cricoid

Question 17

What is the insertion of the Cricothyroid muscle?

Answer 17

Lower border of thyroid cartilage

Question 18

What is the action of the Cricothyroid muscle?

Answer 18

Increase the tension in the vocal ligaments

Question 19

What is the action of the Thyroarytenoid muscle?

Answer 19

Moves arytenoids forwards and thus lessens the tension in vocal ligaments

Question 20

What is the origin of the Lateral crico-arytenoid muscle?

Answer 20

Lateral side of cricoid

Question 21

What is the insertion of the Lateral crico-arytenoid muscle?

Answer 21

Muscular process of arytenoid

Question 22

What is the action of the Lateral crico-arytenoid muscle?

Answer 22

Adducting the vocal ligaments

Question 23

What do the Transverse & Oblique arytenoids aid in?

Answer 23

Adduction by drawing the arytenoids together

Question 24

Where does the Oblique arytenoids run?

Answer 24

From muscular process of one arytenoid to the apex of the other

Question 25

What is the function of the Aryepiglottic muscle?

Answer 25

**Acts as a sphincter**, narrowing the opening into the larynx (laryngeal aditus), and preventing swallowed material from entering it

Question 26

What other structures aid the Aryepiglottic muscle in its function?

Answer 26

- Interarytenoids - Epiglottis

Question 27

What is the origin of the Posterior cricoarytenoid muscles?

Answer 27

**Posterior** aspect of **cricoid**

Question 28

What is the insertion of the Posterior cricoarytenoid muscles?

Answer 28

**Muscular process** of **arytenoid**

Question 29

What is the action of the Posterior cricoarytenoid muscles?

Answer 29

**Abduct the vocal ligaments** by pulling the muscular processes backwards

Question 30

Where is the Upper part of the cavity of the Larynx and what is the name?

Answer 30

Between the **laryngeal inlet** and **vestibular fold** is termed **vestibule**

Question 31

What is the Middle part of the cavity of the Larynx and what is the recess called?

Answer 31

**Ventricle**, from vestibular to vocal fold, and opening into this is a recess called **sinus** of the larynx

Question 32

What is the Lower part of the cavity of the Larynx?

Answer 32

**Infraglottic cavity**, extends from the vocal folds to cricoid cartilage

Question 33

What is the nerve supply?

Answer 33

**Superior** and **recurrent laryngeal** branches of the **Vagus**

Question 34

What do the Superior laryngeal nerve divide into?

Answer 34

**Internal** and **External** branches

Question 35

What does the Internal laryngeal nerve supply?

Answer 35

Supplies **sensory** to **interior** of the **larynx** **above** the vocal folds

Question 36

What does the External laryngeal nerve supply?

Answer 36

Supplies **motor** to **cricothyroid muscle**

Question 37

What does the Recurrent laryngeal nerve supply?

Answer 37

Supplies **motor** to the rest of the **intrinsic muscles** and **sensory below the vocal folds**

Question 38

What is the Arterial Supply?

Answer 38

Through **laryngeal branches** of **Superior** and **Inferior thyroid arteries**

Question 39

Where is the Venous drainage?

Answer 39

**Superior**, **Middle** and **Inferior thyroid** veins

Question 40

Where is the Lymph drainage?

Answer 40

Deep cervical nodes

Question 41

What is the function of the Larynx?

Answer 41

- **Guards** the **lower airway** by its **sphincteric action** - Plays a role in **swallowing** and **cough reflexes**

Question 42

What are the steps in the First Stage of Swallowing

Answer 42

1) Lips are brought together and the teeth into occlusion 2) Tongue is forced against the hard palate by intrinsic muscles 3) Tongue together with the hyoid is **raised** by suprahyoid muscles 4) Bolus is pushed backwards into oropharynx

Question 43

What are the steps in the Second Stage of Swallowing?

Answer 43

1) Soft palate is tensed and elevated 2) Larynx is pulled upwards behind the hyoid 3) Laryngeal opening is closed 4) Contraction of constrictor muscles propels the bolus into the oesophagus

Question 44

What is Dysphagia and what are some causes of it?

Answer 44

Difficulty in swallowing - Neurological disorders involving swallowing reflex - Tumours of pharynx - Tumours of oesophagus