SM_24b: Anatomy of the Larynx

Question 1

Piriform recess is between the ____ and ____

Answer 1

Piriform recess is between the cricoid and thyroid cartilages of the larynx on each side

(food can get stuck there)

(nasopharynx is above the soft palate, epiglottis guards entryway to larynx, thyroid cartilage is a plate)

Question 2

Foramen cecum is ____

Answer 2

Foramen cecum is where thyroid gland buds off foregut

(median glossoepiglottic fold is between tongue and epiglottis in midline, valleculae are spaces on either side of the fold that function as spit traps)

Question 3

Vocal cords attach from ____ to ____

Answer 3

Vocal cords attach from arytenoids to thyroid cartilage

(glottis is true vocal cords)

Question 4

Sternothyroid is attached to ____

Answer 4

Sternothyroid is attached to thyroid cartilage

Question 5

Inferior constrictor attaches the ____ and ____

Answer 5

Inferior constrictor attaches the thyroid cartilage and cricoid cartilage

Question 6

____ enters thyroid from above and responsible for cough reflex

Answer 6

Internal laryngeal nerve enters thyroid from above and responsible for cough reflex

Question 7

Thyroid cartilage is a ___

Answer 7

Thyroid cartilage is a plate

(inferior borders articulate with cricoid cartilage in synovial joint)

Question 8

Describe movements of thyroid cartilage

Answer 8

Thyroid cartilage movements

• Moves back -> vocal cords shorten -> lower pitch of voice
• Abducted -> increase volume of airway
• Adducted -> raise intrabdominal pressure for coughing, labor, etc

Question 9

Thyroid cartilage is adducted to ____

Answer 9

Thyroid cartilage is adducted to raise intrabdominal pressure

(coughing, labor, etc)

Question 10

____ separates true and false vocal folds

Answer 10

Ventricle separates true and false vocal folds

• True folds comprise glottis
• Vestibule is space above the folds
• Infraglottic cavity is below the folds
• Rima glottidis is fissure between true cords

Question 11

____ is above the folds, while ____ is below the folds

Answer 11

Vestibule is space above the folds, while infraglottic cavity is below the folds

Question 12

Triangular membrane is ____

Answer 12

Triangular membrane is conus elasticus

• Bounds infraglottic cavity
• Upper edge is vocal ligament
• Includes cricothyroid ligament / membrane

Question 13

____ bounds vestibule

Answer 13

Quadrangular membrane bounds vestibule

(terminates at vestibular ligament)

Question 14

Lateral cricoarytenoid muscle ____

Answer 14

Lateral cricoarytenoid muscle pulls in opposite side relative to posterior

Question 15

Lateral cricoarytenoid muscle ____

Answer 15

Lateral cricoarytenoid muscle pulls in opposite side relative to posterior

Question 16

Posterior cricoarytenoids ____ by ____, ____ the airway

Answer 16

Posterior cricoarytenoids abduct vocal folds by rotating the arytenoid cartilages, opening the airway

Question 17

Lateral cricoarytenoids ____ and ____ the airway to ____

Answer 17

Lateral cricoarytenoids adduct the vocal folds and close the airway to raise pressure in the thorax and abdomen

(for straining, coughing)

Question 18

Transverse arytenoid pulls ____ to complete ____

Answer 18

Transverse arytenoid pulls arytenoid cartilages together to complete adduction

(works with lateral cricoarytenoid - lateral cricoarytenoid without transverse makes voice a whisper)

Question 19

Cricothyroid pulls thyroid cartilage ___ and ___, the vocal folds to ___

Answer 19

Cricothyroid pulls thyroid cartilage down and forward, stretching the vocal folds to raise the pitch of the voice

Question 20

Thyroarytenoid and vocalis ____ to ____

Answer 20

Thyroarytenoid and vocalis shorten vocal folds to lower the pitch of the voice

(shorten vocal cord)

(vocalis muscle produces graded tension in the vocal ligaments)

Question 21

Aryepiglottic muscle ____, while the thyroepiglottic muscle ____

Answer 21

Aryepiglottic muscle pulls epiglottis posteriorly to help close larynx, while the thyroepiglottic muscle pulls epiglottis forward to help open the larynx

Question 22

Back of vocal folds ____

Answer 22

Back of vocal folds close / open the larynx

Question 23

Vocal cord will remain close to midline in ____

Answer 23

Vocal cord will remain close to midline in recurrent laryngeal nerve paralysis

Question 24

Infrahyoid strap muscles are innervated by the ____

Answer 24

Infrahyoid strap muscles are innervated by the ansa cervicalis

Question 25

Describe vagus branches in the neck

Answer 25

Vagus branches in the neck 1. Pharyngeal branch to constrictor and palate muscles (except tensor) 2. Superior laryngeal splits into internal laryngeal (visceral sensory to larynx above vocal cords) and external laryngeal (motor to cricothyroid muscle), parasympathetics 3. Inferior (recurrent) laryngeal: motor to all other laryngeal muscles, visceral sensory below vocal cords, parasympathetics

Question 26

Internal laryngeal part of superior laryngeal nerve is responsible for \_\_\_\_

Answer 26

Internal laryngeal part of superior laryngeal nerve is responsible for cough relfex

Question 27

Most of thyroid and epiglottis comes from \_\_\_\_, while the cricoid and others come from \_\_\_\_

Answer 27

Most of thyroid and epiglottis comes from Arch 4, while the cricoid and others come from Arch 6

Question 28

Larynx and airway are ____ extensions of the \_\_\_\_

Answer 28

Larynx and airway are ventral splanchnopleure extensions of the foregut

Question 29

In newborns, epiglottis ____ soft palate

Answer 29

In newborns, epiglottis touches soft palate (adults have long pharynx) (nasopharynx is above oropharynx, which is above laryngopharynx)

Question 30

Infant larynx can be elevated to overlap the ____ with the \_\_\_\_, which separates ____ and ____ passes to allow \_\_\_\_

Answer 30

Infant larynx can be elevated to overlap the glottis with the soft palate, which separates air and GI passages to allow easier breathing while suckling

Question 31

Pouch 3 forms \_\_\_\_, while Pouch 4 gives rise to \_\_\_\_

Answer 31

Pouch 3 forms thymus gland, while Pouch 4 gives rise to superior parathyroid (tongue covered with ectoderm)

Question 32

Tongue is on the floor of the ____ and \_\_\_\_

Answer 32

Tongue is on the floor of the stomodeum and foregut