Adult vs Pediatric Larynx
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Differences between Adult and Pediatric Larynx
📍 Position of the Larynx
Pediatric: Positioned higher in the neck, with the glottis lying opposite C3–C4 at rest. During swallowing, it can ascend as high as C1–C2.
Why is Pediatric larynx positionaed higher than adult larynx?
Adult: Located lower in the neck, with the glottis at the level of C5–C6.
🧱 Laryngeal Cartilage Differences
| Feature | Pediatric Larynx | Adult Larynx |
|---|---|---|
| Cartilage Consistency | Soft and collapsible | Firm and stable |
| Epiglottis | Floppy and omega-shaped | Firm and flat |
| Arytenoids | Large and cover posterior glottis | Smaller in size |
| Thyroid Cartilage | Flatter; overlaps cricoid; overlapped by hyoid → narrow cricothyroid & thyrohyoid spaces | Angled (90° in males, 120° in females) → landmarks (e.g., Adam's apple) easily palpable |
🌀 Shape and Size
- Pediatric: Small and conical/funnel-shaped
- Adult: Larger and cylindrical
🔒 Narrowest Point in the Airway
- Pediatric: Subglottic space (below vocal cords) is the narrowest.
🔍 Important when selecting infant endotracheal tubes. - Adult: Glottis (vocal cords) is the narrowest region.
📏 Vocal Cords
| Feature | Pediatric | Adult |
|---|---|---|
| Length (approx.) | 6 mm (females), 8 mm (males) | 15–19 mm (females), 17–23 mm (males) |
| Structure | Immature | Well-differentiated 5-layered structure |
🧫 Mucosal Lining
- Pediatric: Highly reactive mucosa → prone to edema and obstruction in response to trauma or inflammation.
- Adult: Less reactive mucosa → fewer spasms and obstructions.
📊 Membranous to Cartilage Ratio
- Pediatric: 1:1.5
- Adult: 1:5
🌱 Growth Spurts of the Larynx
-
First Growth Spurt: During the first 3 years of life
- Increases in width and length
- Explains why conditions like laryngomalacia often improve without surgery
-
Second Growth Spurt: During adolescence
- Development of thyroid angle
- Lengthening of vocal cords → voice changes during puberty
- Gradual descent of larynx to adult position (C5–C6)
📸 Visual Comparison Highlights
- Tongue: Proportionally larger in infants
- Epiglottis: Floppy and U-shaped in infants; shorter and firmer in adults
- Vocal cords: Upward slant in infants; horizontal in adults
- Cricoid: Narrowest point in infant airway
- Larynx: More anterior and superior in infants
🧠 Easy Mnemonic – The Seven S's of Pediatric Larynx
| S.No | S Term | Description |
|---|---|---|
| 1️ | Size | Smaller overall dimensions |
| 2️ | Shape | Funnel/conical shaped (vs cylindrical in adults) |
| 3️ | Softness | Softer cartilage, prone to collapse |
| 4️ | Superior | Positioned higher in the neck |
| 5️ | Straighter | Less oblique orientation |
| 6️ | Sensitivity | Highly reactive mucosa → more prone to spasm |
| 7️ | Subglottis | Narrowest part of the airway in infants (vs glottis in adults) |
🧾 Conclusion
The Pediatric larynx is not just a smaller version of the adult larynx — it has distinct anatomical and physiological features that are crucial in clinical practice. Recognizing these differences ensures better airway management, appropriate equipment selection, and safer interventions in infants and children.
📝 All the topics and questions mentioned in this post are explained in detail in my ENT notes - built for exam success and clinical understanding. Get full access by purchasing the notes.