Larynx Anatomy PDF

## Larynx **Slimhinden**: - In the upper part of larynx, *vestibulum laryngis*, there are many sensitive nerves. - A small irritation causes coughing. **Larynx protects the lower airways**: - By closing the *aditus laryngis*. - If the closing fails, protection is achieved by coughing. - The prote...

## Larynx **Slimhinden**: - In the upper part of larynx, *vestibulum laryngis*, there are many sensitive nerves. - A small irritation causes coughing. **Larynx protects the lower airways**: - By closing the *aditus laryngis*. - If the closing fails, protection is achieved by coughing. - The protection fails if both closing of the *aditus laryngis* and the cough reflex are disabled, e.g. during general anesthesia. - Blood from the mouth can enter the trachea, bronchi and lungs. - If the stomach is not empty during anesthesia, vomiting can lead to vomit entering the lower airways and lungs. - Both situations can be life-threatening. **Larynx protects in general**: - The function is vital. - Unconscious people have no protection, therefore it is dangerous to give them liquids. - Liquids run down the airways. - Most people experience the feeling of something stuck in their throat: * Usually it's only a small piece of food or something else. * However, the irritation of the mucosa in the upper part of the larynx causes forceful coughing to eject the irritant. * Many people believe that the irritant has gone all the way down the trachea. * This is usually not the case. **Location of the larynx**: - It is located with the *pharynx* in the *spatium viscerale*. - It is in front of *pars laryngea pharyngis*. - It is located in front of the lower cervical vertebrae. - It is located between the right and left *spatium lateropharynx*. - In men, it creates the **'Adam's apple'** on the front of the neck. - The *Adam's apple* is the front part of the **thyroid cartilage**. **Layers of the *larynx*** - *Tunica mucosa* (1) - *Tela submucosa* (2) with: - *Cartilages* (8) - *Muscles* (7) - *Membranes* (6) - *Glands* - *Blood vessels* - *Nerves* - *Adventitia* (3) **Mucous membrane**: - Where the *tunica mucosa* is subject to mechanical stress, there is a stratified squamous epithelium. - This applies to the true vocal folds (4) and the back of the epiglottis. - The other areas have respiratory epithelium (5), which is a single-layered ciliated columnar epithelium with cilia and goblet cells. **Cartilages of the larynx**: - **Thyroid cartilage** (5) - It is the largest cartilage in the larynx. - Consists of two plates that are connected in the front. - There is a significant distance between the plates in the back. - The **cricoid cartilage** (4) is located below it. - *Cricoid cartilage* resembles a signet ring with the plate in the back. - It creates a joint with the *thyroid cartilage*. - On the upper edge of the *cricoid cartilage* there are two small pyramidal *cartilagines arytenoideae* (3) that can slide and rotate on the edge of the signet-shaped plate. - **Epiglottic cartilage** (2) - It is a long, narrow, triangular plate. - It is attached to the *hyoid bone* (1). - The tip is situated in the angle between the two plates of the *thyroid cartilage*. - It is made of elastic cartilage. - All other cartilages are made of hyaline cartilage. - There are some additional small *cartilages*. **Small cartilages**: - The small *cartilagines arytenoideae* (3) can slide forward/backward, from side to side and rotate around a vertical axis. - The true vocal folds (3) are connected to the tip of the *arytenoid cartilage* (9). - When the *arytenoid cartilage* is closed, vocal cords are closed and a voice can be created. **Thyroid cartilage**: - It is attached to the hyoid bone (4) by a connective tissue membrane (the top 6 numbers). - There are membranes (6) in the *tela submucosa*, connecting the cartilages. - These membranes sometimes form reinforcements "ligaments" and are present in the true vocal cords (3) , the false vocal cords (2) and in the *plica aryepiglottica* (7) that limits the *aditus laryngis*. ***Aditus laryngis** (10): - This is the entrance to the larynx. - The *aditus laryngis* is seen from behind. - It is limited by the epiglottis (9) and by the right and left *plica aryepiglottica* (11). - The name suggests that the fold of mucosa protrudes from the *cartilago arytenoidea* to the *epiglottic cartilage*. **Movement of the cartilages**: - They can move relative to each other using striated muscles. - The movement makes it possible to close the *rima glottidis* and the *aditus laryngis*. - Also, tensed and relaxed vocal cords can be created during the process. **Muscles of the larynx**: - **Inner muscles** are divided into: - Muscles (1) that close the *aditus laryngis* (4) and narrow the upper part of the *larynx*. - Muscles (3) that pull the vocal cords together, resulting in voice production (*stemmebåndsadduktorer*). - **Outer muscles**.