Systemic Anatomy for Respiratory Technology of the Respiratory Therapy Program (PDF)

Systemic anatomy for respiratory Technology Of the Respiratory Therapy Program by Marwa Abdel- Samad Al-Gholam MD Anatomy and Embryology Assistant professor of Anatomy and...

Systemic anatomy for respiratory Technology Of the Respiratory Therapy Program by Marwa Abdel- Samad Al-Gholam MD Anatomy and Embryology Assistant professor of Anatomy and Embryology Menoufia University  Objectives (Ilos) By the end of this lecture, the student should be able to: ❑ Describe the anatomy of the laryngeal cartilage. ❑ Describe nerve, blood supply, and venous drainage of the larynx. ❑ The vocal cord of the larynx represents a watershed, explain Anatomy of the larynx Anatomy of the larynx It is an organ that provides a *protective sphincter at the inlet of the airway passages and *is responsible for voice production The larynx is located in front of the neck opposite the third to sixth cervical vertebrae in adult. The larynx extends from the upper border of epiglottis to the lower margin of cricoid cartilage. ▪ The framework of the larynx is formed of *Cartilage *Ligaments *Membranes *Muscles *Mucous membrane. The vocal cord of the larynx represents a watershed, which divides the larynx into upper and lower parts with different source of blood supply and nerve supply and different directions of lymph drainage ▪ It opens in the laryngopharynx through the laryngeal inlet It is continuous with the trachea below. Cartilages of larynx Epiglottis Thyroid Cricoid Cricoid Single Paired Epiglottis. Arytenoids. Thyroid. Corniculates. Cricoid Cuneiforms Cartilages of larynx ▪ This is the largest cartilage of the larynx. ✓ Consists of two laminae of hyaline cartilage which meet in the midline anteriorly at the thyroid angle but leave the thyroid notch between them above ✓ The angle at which the 2 laminae meet is about 90 in male (Adam’s apple) and 120 in females. o The posterior border extends upwards as superior horn and downwards as inferior horn. o On the outer surface of lamina, there is an oblique line for muscle attachment. Its shape is like that of a signet ring. Its broad lamina is posterior and its narrow arch is anterior to the laryngeal cavity. Lies below the thyroid cartilage. ❑ The fact on the lateral surface articulate with the thyroid cartilage to form cricothyroid joint. ❑ The upper border of lamina articulates with arytenoid cartilage to form crico-arytenoid joint. Crico-arytenoid joint It is a three-sided pyramid. It has a base and apex). The apex articulates with corniculate cartilage. The base articulates with the cricoid to form the cricoarytenoid joint.  Corniculate cartilage Apex Base It has two processes (vocal and muscular)).  The apex articulates with corniculate cartilage. The base articulates with the superior border of lamina of cricoid to form the cricoarytenoid joint. It is a leaf-shaped elastic cartilage. It has anterior and posterior surfaces and two lateral margins. Its upper end is free and broad and lower end is narrow and pointed.  Hyoid Its upper end Epiglottis projects upwards and backwards behind the hyoid bone and the base of tongue. Tongue  Upper end Anteriorly, It articulates with the hyoid bone By, Hyo- Lower end epiglottic (Stalk) ligament articulates with the thyroid cartilage  Upper end Anteriorly, It attaches to the tongue By Median and 2 lateral Glosso- epiglotic lig Side of upper end It attaches to the apex of arytenoid By Ary-epiglottic folds Aryepiglottic ligament Cuneiform and corniculate cartilages The cuneiform is cartilage within the posterior end of the aryepiglottic fold. The corniculate lies in the posterior parts of the aryepiglottic folds and articulates with arytenoid cartiage. Both cartilages support the aryepiglottic fold of their side. Boundaries Muscles of larynx: Extrinsic Muscles: These muscles move the larynx up and down during swallowing. Intrinsic Muscles: 1. Muscles that increase or decrease the length and tension of the vocal cords: 2. Muscles that abduct or adduct the vocal cords: 3. Muscles that open or close the laryngeal inlet: All the intrinsic muscles of the larynx are supplied by recurrent laryngeal nerve except cricothyroid, which is supplied by the external laryngeal nerve. Clinical Considerations 1. Unilateral Damage to the Recurrent Laryngeal Nerve. It will result in a hoarse voice, inability to speak for long periods, and movement of the vocal fold on the affected side toward the midline. 2. Bilateral Damage to the Recurrent Laryngeal Nerve. It will result in acute breathlessness (dyspnea) since both vocal folds move toward the midline and close off the air passage. Laryngeal obstruction: ❑ The mucous membrane of the superior part of the larynx is very sensitive. ❑ When foreign enters into the laryngeal inlet it causes immediate explosive coughing and the foreign body is expelled out. ❑ If this reflex is slowed or absent as in a neurological lesion or after consuming alcohol, a foreign may enter the laryngeal cavity and cause choking (i.e., laryngeal obstruction). ❑ Choking by food is a common cause of laryngeal obstruction and asphyxia. If the foreign body is not dislodged and expelled immediately by Heimlich maneuver, a person will die within minutes, almost certainly before there is time to take him to the hospital.