MUSCLES OF LARYNX
Abductor of vocal cord is
| A |
Posterior cricoarytenoid |
|
| B |
Cricothyroid |
|
| C |
Interarytenoid |
|
| D |
Lateral cricoaretynoid |
Abductor of vocal cord is
| A |
Posterior cricoarytenoid |
|
| B |
Cricothyroid |
|
| C |
Interarytenoid |
|
| D |
Lateral cricoaretynoid |
INTRINSIC MUSCLES ACTING ON VOCAL CORDS:
|
Abductors |
Posterior cricoarytenoid |
|
Adductors |
Lateral cricoarytenoid, Interarytenoid (transverse arytenoid) Thyroarytenoid (external part) |
|
Tensors |
Cricothyroid Vocalis (internal part of thyroarytenoid) |
INTRINSIC MUSCLES ACTING ON LARYNGEAL INLET:
|
Openers of laryngeal inlet |
Thyroepiglottic (part of thyroarytenoid) |
|
Closers of larylngeal inlet |
Interarytenoid (oblique part), Aryepiglottic (posterior oblique part of interarytenoids) |
| A | Superior constrictor | |
| B | . Inferior constrictor | |
| C | Thyrohyoid | |
| D | Stern thyroid |
| A | Superior constrictor | |
| B | . Inferior constrictor | |
| C | Thyrohyoid | |
| D | Stern thyroid |
Superior constrictor
|
MUSCLE Superior constrictor (Constrictor of pharynx) |
ORIGIN i. Pterygoid hamulus ii. Pterygomandibular raphe iii. Medial surface of mandible (near lower attachment of pterygomandibular raphe |
INSERTION Median raphe on posterior wall of pharynx |
|
Inferior constrictor (Constrictor of Two parts: pharynx) |
i. Thyropharyngeus – from thyroid cartilage (oblique line of thyroid cartilage) ii. Cricopharyngeus – from cricoid cartilage |
Median raphe on posterior wall of pharynx |
|
Sternothyroid (Infrahyoid muscle) |
i. Posterior surface of manubrium sterni ii. Adjoining part of first costal cartilage |
Oblique line of thyroid cartilage |
|
Thyrohyoid (Infrahyoid muscle) |
Oblique line of thyroid cartilage |
Lower border of body and greater cornua of hyoid bone |
Abductor of the larynx is:
| A |
Crico-arytenoideus posterior |
|
| B |
Crico-arytenoideus lateralis |
|
| C |
Arytenoideus transversus |
|
| D |
Vocalis muscle |
Abductor of the larynx is:
| A |
Crico-arytenoideus posterior |
|
| B |
Crico-arytenoideus lateralis |
|
| C |
Arytenoideus transversus |
|
| D |
Vocalis muscle |
Which is the only muscle that is located on the external aspect of larynx?
| A |
Cricothyroid |
|
| B |
Lateral cricoarytenoid |
|
| C |
Thyroarytenoid |
|
| D |
Posterior cricoarytenoid |
Which is the only muscle that is located on the external aspect of larynx?
| A |
Cricothyroid |
|
| B |
Lateral cricoarytenoid |
|
| C |
Thyroarytenoid |
|
| D |
Posterior cricoarytenoid |
- Posterior cricoarytenoid
- Cricothyroid
- Thyroarytenoids
- Lateral cricoarytenoid
- Transverse arytenoids
- Vocalis
- Thyroarytenoid
Which one of the following muscle is functioning as tensor of vocal cord during phonation?
| A |
Post cricoarytenoid |
|
| B |
Interarytenoid |
|
| C |
Lateral cricothyroid |
|
| D |
Cricothyroid |
Which one of the following muscle is functioning as tensor of vocal cord during phonation?
| A |
Post cricoarytenoid |
|
| B |
Interarytenoid |
|
| C |
Lateral cricothyroid |
|
| D |
Cricothyroid |
Major Muscles of the Larynx:
|
Muscle |
Function |
Innervation |
Key Point |
|
Posterior cricoarytenoid |
Abducts, tenses vocal folds |
Recurrent laryngeal nerve |
Only abductor of vocal folds |
|
Lateral cricoarytenoid |
Adducts true vocal folds |
Recurrent laryngeal nerve |
|
|
Interarytenoid |
Adducts posterior glottis |
Recurrent laryngeal nerve |
Only laryngeal muscle receiving bilateral innervation |
|
Oblique arytenoids |
Closes laryngeal inlet during swallowing |
Recurrent laryngeal nerve |
|
|
Thyroarytenoid |
Adducts, tenses vocal fold |
Recurrent laryngeal nerve |
|
|
Cricothyroid |
Increases vocal fold tension, especially at higher pitches |
External branch of superior laryngeal nerve |
Only muscle not innervated by recurrent laryngeal nerve |
Which of the following muscle is known as safety muscle of larynx?
| A |
Cricothyroid |
|
| B |
Thyroarytenoid |
|
| C |
Lateral cricoarytenoid |
|
| D |
Posterior cricoarytenoid |
Which of the following muscle is known as safety muscle of larynx?
| A |
Cricothyroid |
|
| B |
Thyroarytenoid |
|
| C |
Lateral cricoarytenoid |
|
| D |
Posterior cricoarytenoid |
- Cricothyroid
- Thyroarytenoids
- Lateral cricoarytenoid
- Transverse arytenoids
- Vocalis
- Thyroarytenoid
Which of the following muscle of the larynx acts as abductor of vocal cords?
| A |
Lateral cricoarytenoid |
|
| B |
Posterior cricoarytenoid |
|
| C |
Anterior cricoarytenoid |
|
| D |
Cricothyroid |
Which of the following muscle of the larynx acts as abductor of vocal cords?
| A |
Lateral cricoarytenoid |
|
| B |
Posterior cricoarytenoid |
|
| C |
Anterior cricoarytenoid |
|
| D |
Cricothyroid |
- Lateral cricoarytenoid
- Transverse arytenoid
All the muscles of the larynx are supplied by the recurrent laryngeal nerve, EXCEPT?
| A |
Cricothyroid |
|
| B |
Salpingopharyngeus |
|
| C |
Stylopharyngeus |
|
| D |
None of the above |
All the muscles of the larynx are supplied by the recurrent laryngeal nerve, EXCEPT?
| A |
Cricothyroid |
|
| B |
Salpingopharyngeus |
|
| C |
Stylopharyngeus |
|
| D |
None of the above |
All the intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve except for cricothyroid, which is supplied by the external laryngeal nerve.
Adductors of vocal cord
| A |
Posterior cricoarytenoids |
|
| B |
Cricothyroid |
|
| C |
Transverse arytenoids |
|
| D |
Voccalis |
Adductors of vocal cord
| A |
Posterior cricoarytenoids |
|
| B |
Cricothyroid |
|
| C |
Transverse arytenoids |
|
| D |
Voccalis |
Transverse (oblique) arytenoids
All are elevators of larynx except:
| A |
Thyrohyoid |
|
| B |
Digastric |
|
| C |
Stylohyoid |
|
| D |
mylohyoid |
All are elevators of larynx except:
| A |
Thyrohyoid |
|
| B |
Digastric |
|
| C |
Stylohyoid |
|
| D |
mylohyoid |
The main laryngeal elevators are: Digastric anterior and posterior, the stylohyoid, mylohyoid, geniohyoid, genioglossus, hyoglossus, and thyropharyngeus muscles
Sensory nerve supply of larynx below the level of vocal cord is:
| A |
External branch of superior laryngeal nerve |
|
| B |
Internal branch of superior laryngeal nerve |
|
| C |
Recurrent laryngeal nerve |
|
| D |
Inferior pharyngeal |
Sensory nerve supply of larynx below the level of vocal cord is:
| A |
External branch of superior laryngeal nerve |
|
| B |
Internal branch of superior laryngeal nerve |
|
| C |
Recurrent laryngeal nerve |
|
| D |
Inferior pharyngeal |
Nerve supply of larynx
- Sensory:
– The internal laryngeal nerve supplies the mucous membrane up to the level of the vocal folds.
– The recurrent laryngeal nerve supplies below the level of the vocal folds.
- Motor:
– All intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve except for the cricothyroid which is supplied by the external laryngeal nerve.
A patient met with recurrent laryngeal nerve palsy while undergoing thyroid surgery. Which of the following muscles of larynx is/are affected?
| A |
Posterior crioarytenoid |
|
| B |
Lateral cricoarytenoid |
|
| C |
Thyroarytenoid |
|
| D |
All |
A patient met with recurrent laryngeal nerve palsy while undergoing thyroid surgery. Which of the following muscles of larynx is/are affected?
| A |
Posterior crioarytenoid |
|
| B |
Lateral cricoarytenoid |
|
| C |
Thyroarytenoid |
|
| D |
All |
All muscles which move the vocal cord (abductors, adductors or tensors) are supplied by the recurrent laryngeal nerve except the cricothyroid muscle which is supplied by external laryngeal nerve (a branch of superior laryngeal nerve).
Which of the following is the only intrinisic muscle of larynx that lies outside the laryngeal framework?
| A |
Cricothyroid |
|
| B |
Superior constrictor |
|
| C |
Cricopharyngeus |
|
| D |
Lateral cricothyroid |
Which of the following is the only intrinisic muscle of larynx that lies outside the laryngeal framework?
| A |
Cricothyroid |
|
| B |
Superior constrictor |
|
| C |
Cricopharyngeus |
|
| D |
Lateral cricothyroid |
Cricothyroid muscle is the only intrinsic muscle which is supplied by external laryngeal nerve and lies outside the laryngeal framework
Safety muscle of larynx:
| A |
Lateral cricoarytenoid |
|
| B |
Transverse arytenoid |
|
| C |
Posterior cricoarytenoid |
|
| D |
Cricothyroids |
Safety muscle of larynx:
| A |
Lateral cricoarytenoid |
|
| B |
Transverse arytenoid |
|
| C |
Posterior cricoarytenoid |
|
| D |
Cricothyroids |
- During forced inspiration, both parts of the rima are triangular, so that the entire rima is lozenge shaped; the vocal cords are fully abducted and we all know that muscles which open the glottis, are posterior cricoarytenoids. So in one way we can consider them as safety muscles which help in respiration (forced inspiration)
The muscle which is not supplied by this nerve(with arrow) in this image
| A |
Thyroarytenoid |
|
| B |
Posterior cricoarytenoid |
|
| C |
Cricothyroid |
|
| D |
Lateral cricoarytenoid |
The muscle which is not supplied by this nerve(with arrow) in this image
| A |
Thyroarytenoid |
|
| B |
Posterior cricoarytenoid |
|
| C |
Cricothyroid |
|
| D |
Lateral cricoarytenoid |
Nerve is Recurrent laryngeal
- Thyroarytenoid muscle:- R and L muscles; attached to thyroid and arytenoid cartilages on each side.
- Lateral cricoarytenoid muscle: (R and L muscles):– Attached to cricoid and arytenoid cartilage on each side. Closes or adducts vocal folds. Supplied by Recurrent laryngeal nerve
- Cricothyroid muscle: Attached to cricoid and thyroid cartilages. Tilts the thyroid cartilage, thus increasing tension of vocal folds
- Posterior cricoarytenoid muscleAttached to cricoid and arytenoid cartilages Move arytenoid cartilages so as to move both vocal folds apart, “open” of abduct vocal foldsSupplied by Recurrent laryngeal nerve
Nerve supply of larynx above level of vocal cord
| A |
Superior laryngeal |
|
| B |
Recurrent laryngeal |
|
| C |
Glossopharyngeal |
|
| D |
External laryngeal |
Nerve supply of larynx above level of vocal cord
| A |
Superior laryngeal |
|
| B |
Recurrent laryngeal |
|
| C |
Glossopharyngeal |
|
| D |
External laryngeal |
Ans. is ‘a’ i.e., Superior laryngeal
Nerve supply of larynx
- The main cranial nerve innervating the larynx is the vagus nerve via its branches; superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN).
- Sensory supply of larynx
- Above the level of vocal cords, larynx is supplied by internal laryngeal nerve, a branch of superior laryngeal nerve.
- Below the vocal cord, larynx is supplied by recurrent laryngeal nerve.
- Motor supply of larynx
- All the intrinsic muscles of larynx are supplied by recurrent laryngeal nerve except for cricothyroid muscle.
- Cricothyroid is supplied by external laryngeal nerve, a branch of superior laryngeal nerve.
Which muscle of larynx is not supplied by recurrent laryngeal nerve ‑
| A |
Vocalis |
|
| B |
Thyroarytenoid |
|
| C |
Cricothyroid |
|
| D |
Interarytenoid |
Which muscle of larynx is not supplied by recurrent laryngeal nerve ‑
| A |
Vocalis |
|
| B |
Thyroarytenoid |
|
| C |
Cricothyroid |
|
| D |
Interarytenoid |
Ans. is ‘c’ i.e., Cricothyroid
- All intrinsic muscles are supplied by the reccurrent laryngeal nerve except cricothyroid which is supplied by the external laryngeal nerve
