Cavitas Nasi Propria 16.pdf

## Cavitas nasi propria - Cavitas nasi propria (3) is restricted by mucous membrane covered surfaces - Nasal septum - Roof - Floor - Lateral walls ## Nasal septum - The nasal septum consists of cartilage (1) in the front third and bone (2) in the back two thirds - Vomer - The...

## Cavitas nasi propria - Cavitas nasi propria (3) is restricted by mucous membrane covered surfaces - Nasal septum - Roof - Floor - Lateral walls ## Nasal septum - The nasal septum consists of cartilage (1) in the front third and bone (2) in the back two thirds - Vomer - The roof of the nasal cavity is narrow - Front part is formed by the nasal bridge skeleton (6) - Further back, the roof is formed by lamina cribrosa of the ethmoid bone (7) - Lastly, the roof is formed by the spenoid bone (8) - The floor of the nasal cavity is formed by the hard palate (4) - The lateral wall on each side contains three nasal conchae (5) - The lowest concha is a separate bone - The others belong to the ethmoid bone ## Nerve cells in the olfactory region - Nerve cells (3) are located between epithelial cells and work as support cells ## Neurites - Neurites, axons are thin threads (4) that run within connective tissue (2) - It’s rare to find nerve cell bodies in a mucosal epithelium, they are found in humans. ## Epithelium in the respiratory region - The epithelium (1) of the respiratory region is single-layered, multi-rowed prismatic epithelium. - The epithelium contains cilia (3) and goblet cells (4) - The epithelium (fig. 12) (1) is a typical respiratory epithelium, every cell reaches the basal membrane, but sometimes only with a thin stalk. - This makes the epithelium seem single-layered, but the nuclei are in several rows due to cell height differences. - The same epithelium can be found in the nasal pharyngeal region - The oral part of the pharynx has stratified squamous epithelium, because the oral part of the pharynx also works as a food conduit. ## Air flow - Air flows from the nasal cavity, through the choanae, to the pharynx (1) - The pharynx is part of the upper respiratory tract with the nasal part and oral part - The nasal pharynx (1) acts as an airway. - The oral pharnyx (2) functions as an airway and a food conduit. ## Nasal conchae - Nasal conchae (2) are thin, bent bone plates - They are covered by a thick mucous membrane (6) - The nasal passages (3) lie between the nasal conchae in an anteroposterior direction. - The inferior nasal meatus lies beneath the inferior nasal concha (1) - Here is the opening (1) of the tear duct, canalis nasolacrimalis (2) ## Paranasal sinuses - The paranasal sinuses open into the nasal cavity - Maxillary sinus (6) - Frontal sinus (3) - Ethmoid cells (4) - Sphenoid sinus (5) - The openings are small, and close easily when the mucous membrane swells, for example when you have a cold - This blocks the drainage of the secretion that is produced in the sinuses ## The opening of the frontal and maxillary sinuses - The opening of the frontal sinus (3) is found under the middle nasal concha (M) - The maxillary sinus (6) opens next to the roof, in the nasal cavity - The sphenoid sinus (5) opens closest to the roof. ## Nasal mucosa - The nasal mucosa (6 and white) is strongly attached to bones and cartilage - It is thick, contains many blood vessels and gland tissue. - The mucosa can be divided into the olfactory region (2) and the respiratory region (1) - The olfactory region is small, it is located on the uppermost nasal concha, the roof, and the adjacent part of the nasal septum - The rest of the mucosa belongs to the respiratory region. ## Epithelium in the olfactory region - The epithelium (1) in the olfactory region is a special type, a large proportion of the cells are bipolar nerve cells (3) ## Larynx - The larynx (3) connects the pharnyx to the trachea and forms the beginning of the lower respiratory tract. - The opening into the larynx is the aditus laryngis (2) - The aditus laryngis is connected to the pharynx (lowest line next to 1) via the larynx (3) to the trachea (4). ## The larynx - The larynx (1) is a mucous membrane covered tube with a hourglass shaped lumen (within the dotted lines). - The narrowest part of the tube contains two pairs of vertically arranged mucous membrane folds. - The upper one are the right and left false vocal folds, plica vestibularis (2) - The lower one are the right and left true vocal folds, plica vocalis (3) - The larynx walls contain cartilage, which provides support for the soft tissue. - Muscles can move the cartilage, which changes the shape of the larynx. ## Opening into the larynx - The opening into the larynx, aditus laryngis (4), closes during swallowing. - The glottis, rima glottidis, lies between the right and left true vocal folds (3). - This can be narrowed and widened during speech, for example. - When the two true vocal cords come to meet in the middle line, the glottis closes completely.