Summary of "Anatomie du Larynx"
Summary of Scientific Concepts and Discoveries on the Anatomy of the Larynx
Location and General Description
The larynx is a part of the respiratory tract, centrally located in the neck. It measures about 5 cm in length and 3.4 cm in diameter. Positioned obliquely downwards and backwards, it connects the pharynx above to the trachea below.
Cartilages of the Larynx
Three Large Cartilages
- Cricoid cartilage: Located inferiorly, it encircles the airway and is shaped like an arch anteriorly. It serves as an attachment site for muscles and ligaments.
- Thyroid cartilage: The largest cartilage, formed by two fused laminae creating the Adam’s apple. It is more prominent in men due to a sharper angle (~90° in men, 110–120° in women).
- Epiglottis: Leaf-shaped and inclined backward, it attaches to the thyroid cartilage via the thyroepiglottic ligament. Its primary function is to protect the airway during swallowing.
Three Small Cartilages
- Arytenoid cartilage: Pyramid-shaped, articulates with the cricoid cartilage, and has muscular and vocal processes.
- Corniculate cartilage: Conical in shape, it sits atop the arytenoids.
- Cuneiform cartilage: Small and located internally near the arytenoids and epiglottis.
Ligaments of the Larynx
The ligaments are divided into two groups:
-
Extrinsic ligaments: Connect the larynx to neighboring structures.
- Includes the thyrohyoid membrane (between thyroid cartilage and hyoid bone), hyoepiglottic ligament, and cricotracheal ligament.
-
Intrinsic ligaments: Connect parts of the larynx to each other, ensuring coordinated function.
- Includes the cricothyroid ligament (with vocal ligament thickening) and the quadrangular membrane (with vestibular ligament thickening).
Folds and Membranes
- The vocal and vestibular ligaments form a sphincter mechanism.
- The quadrangular membrane connects the arytenoid cartilage to the epiglottis, forming the aryepiglottic fold.
- The larynx contains:
- Vestibular folds (false vocal cords) located superiorly.
- Vocal folds (true vocal cords) located inferiorly.
Articulations
- Cricothyroid joint: Allows the thyroid cartilage to tilt forward and downward, adjusting tension on the vocal cords.
- Cricoarytenoid joint: Permits movement of the arytenoid cartilages, facilitating vocal fold movement and phonation.
Laryngeal Cavity and Regions
The laryngeal cavity is lined by mucous membrane continuous with the pharynx and trachea. It is divided into three regions:
- Vestibule: Between the aditus (laryngeal inlet) and vestibular folds.
- Glottis: Between the vestibular and vocal folds; includes the vocal folds and ventricles.
- Infraglottic region: Extends from the vocal folds to the trachea.
The ventricles produce lubricants essential for vocal cord function.
Vascularization
- Supplied by:
- Superior laryngeal artery (branch of the superior thyroid artery).
- Inferior laryngeal artery (branch of the inferior thyroid artery).
- Venous drainage occurs via the superior and inferior laryngeal veins into the internal jugular and subclavian veins, respectively.
Innervation
Motor and sensory innervation is provided by branches of the vagus nerve: - Superior laryngeal nerve - Recurrent laryngeal nerve
Functions of the Larynx
- Respiration: Regulates airflow during breathing; vocal and vestibular folds adjust the opening.
- Phonation: Movement of arytenoid cartilages adjusts vocal ligament tension to produce sound.
- Protection: The epiglottis closes the laryngeal inlet during swallowing to prevent aspiration.
- Reflexes: Vocal folds close during forced breath-holding to maintain thoracic pressure.
Clinical Relevance
Disorders such as vocal fold paralysis or papillomavirus infection can affect voice and airway protection. Treatments exist that can restore vocal fold function, as demonstrated by before-and-after clinical cases.
Researchers/Sources Featured
- Pierre Caminade (clinical anatomy descriptions)
- Theo (clinical anatomy descriptions)
This summary outlines the detailed anatomical structure, functional aspects, and clinical significance of the larynx as presented in the video.
Category
Science and Nature
