Understanding the Larynx and Trachea Anatomy

Mar 2, 2025

Lecture Notes on the Larynx, Trachea, and Related Structures

Larynx Anatomy

  • Key Structures:
    • Adam's Apple: Also known as the thyroid cartilage.
    • Epiglottis: Prevents food from entering the larynx.
    • Cricoid Cartilage: Connects larynx to the trachea.
    • Paired Cartilages:
      • Arytenoid
      • Corniculate
      • Cuneiform

Differences between Males and Females

  • Testosterone during puberty:
    • Thickens and enlarges vocal cords in males, causing voice changes.
    • Affects thyroid cartilage visibility, more pronounced in males.
  • Estrogen in females prevents the size change of thyroid cartilage.
  • Hyoid Bone: Anchors the tongue; aids in swallowing and talking.

Trachea Anatomy

  • Structure: Rings (C-rings) keep it open, similar to a vacuum hose.
  • Function: Allows air passage; prevents collapse regardless of pressure changes.
  • C-Rings: Do not make a complete circle; the back is open to accommodate the esophagus.

Vocal Cords

  • False Vocal Cords: Also known as ventricular folds.
  • True Vocal Cords:
    • Contains skeletal muscle and elastic ligament.
    • Sound production involves air pushing past tightened vocal cords.
    • Pitch and volume controlled by tension and airflow.

Speech Mechanics

  • Involves: Pharynx, mouth, nasal cavity, sinuses, tongue, and lips.
  • Pitch: Controlled by vocal fold tension.
  • Volume: Controlled by the amount of air passed.

Health Considerations

  • Laryngitis: Inflammation of the larynx.
  • Larynx Cancer: Predominantly found in smokers and those with HPV.

Human Papillomavirus (HPV)

  • HPV and Cancer:
    • Major cause of cervical, anal, and throat cancer.
    • Types 16 and 18 are significant in the U.S.
  • Vaccination: Recommended to prevent HPV-related cancers.

Trachea and Bronchi

  • Trachea: Extends from the larynx to primary bronchi.
  • Bronchus Branching:
    • Primary, secondary, and tertiary bronchi.
    • Branch into bronchioles (no cartilage).
  • Asthma and Anaphylaxis:
    • Constriction of bronchioles makes breathing difficult.
    • EpiPen use in emergencies to dilate airways.

Medical Interventions

  • Tracheostomy/Tracheotomy: Reestablishes airflow in obstructions or long-term intubation.
  • Intubation: Used during surgeries or respiratory issues; prolonged use may require tracheotomy to prevent vocal cord damage.

Bronchial Tree

  • Hierarchy:
    • Primary Bronchi → Secondary Bronchi → Tertiary Bronchi → Bronchioles → Terminal Bronchioles → Respiratory Bronchioles → Alveolar Ducts → Alveoli
  • Function: Efficient air passage and gas exchange.

These notes capture key anatomical features, functions, health considerations, and interventions related to the larynx and trachea, providing a foundational understanding for further study.

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