Nose & Sinuses

The cribriform plate is indeed a part of the ethmoid bone. It is a thin, sieve-like structure that forms the roof of the nasal cavity and separates it from the cranial cavity. The ethmoid bone is located at the midline of the skull, between the nasal cavity and the brain. It is responsible for supporting the nasal passages and contributing to the formation of the eye sockets.

After the extraction of maxillary molars, the maxillary sinus can enlarge and expand. This is because the roots of the maxillary molars are in close proximity to the maxillary sinus. When these teeth are removed, it creates a void in the bone, which allows the sinus to expand into the space. This enlargement of the maxillary sinus can sometimes lead to complications such as sinusitis or difficulty in placing dental implants in the future. Therefore, it is important for dentists to assess the condition of the maxillary sinus before performing any extractions.

In order to view the paranasal sinuses on a skull, it is necessary to first identify the nasal conchae. The nasal conchae are bony structures located inside the nasal cavity that help to increase the surface area of the nasal passages. By identifying the nasal conchae, one can then locate the paranasal sinuses, which are air-filled spaces within the bones of the skull surrounding the nasal cavity. Therefore, the statement "in order to view the paranasal sinuses (on a skull) one should first identify the nasal conchae" is true.

The choana is indeed the area located at the posterior end of the nasal septum. It serves as the connection between the nasal cavity and the nasopharynx. This opening allows for the passage of air from the nose into the throat.

The statement is true because the opening for the maxillary sinus is indeed located at the posterior inferior end of the iatus semilunaris. The maxillary sinus is one of the paranasal sinuses located in the maxillary bone, and it drains into the nasal cavity through this opening. The iatus semilunaris is a groove in the lateral wall of the nasal cavity, and its posterior inferior end serves as the opening for the maxillary sinus.

The nasolacrimal duct opens into the inferior meatus. The nasolacrimal duct is responsible for draining tears from the eye into the nasal cavity. It starts from the lacrimal sac and travels downwards to open into the inferior meatus of the nasal cavity. This allows tears to be drained away from the eye and into the nose.

The vomer and ethmoid bones form the main part of the nasal septum. The vomer is a thin, flat bone that runs vertically in the midline of the nasal cavity, separating it into two halves. The ethmoid bone, located at the roof of the nasal cavity, also contributes to the nasal septum. Together, these bones provide structural support and help maintain the shape and integrity of the nasal cavity.

The statement that "the 3 nasal concha on each side of the nasal cavity all come from the ethmoid" is false. The nasal conchae are bony structures located inside the nasal cavity, and while the superior and middle nasal conchae do arise from the ethmoid bone, the inferior nasal concha is a separate bone altogether. Therefore, the correct answer is false.

The hiatus semilunaris is found in the middle meatus. The middle meatus is a space in the nasal cavity that is located between the superior meatus and the inferior meatus. It is an important anatomical feature as it serves as a drainage pathway for the frontal sinus, maxillary sinus, and anterior ethmoidal cells. The hiatus semilunaris is a curved groove within the middle meatus that helps to direct the flow of mucus and other secretions towards the nasolacrimal duct, which ultimately drains into the nasal cavity.

The correct answer is the inferior meatus. The nasolacrimal duct is a small tube that drains tears from the eye into the nasal cavity. It is located within the inferior meatus, which is a passage in the nasal cavity. The inferior meatus is situated below the middle nasal conchae and above the choana. The hiatus semilunaris is a groove in the lateral wall of the nasal cavity, but it does not contain the nasolacrimal duct. Therefore, the correct location for the nasolacrimal duct is the inferior meatus.

The ethmoid bulla is found in the middle meatus. The middle meatus is a space in the nasal cavity that lies between the inferior and superior meatuses. It is the location where the ethmoid bulla, a rounded prominence on the lateral wall of the nasal cavity, is situated. The ethmoid bulla is formed by the anterior ethmoidal cells and is an important anatomical landmark in the nasal cavity.

The frontal and sphenoid sinuses are two of the four pairs of paranasal sinuses located in the skull. The frontal sinuses are situated above the eyes, while the sphenoid sinuses are located behind the nose. These sinuses do indeed cross over the midline, meaning that they extend to both sides of the midline of the skull. This anatomical arrangement allows for a more efficient distribution of mucus and airflow within the sinuses.

ethmoid

The sphenoethmoidal recess is found in the posterior-superior portion of the nasal cavity. This means that it is located towards the back and upper part of the nasal cavity.

The statement is false because the epithelium of the nasal cavity is not entirely composed of pseudostratified columnar epithelium. The nasal cavity contains different types of epithelial cells, including pseudostratified columnar epithelium, stratified squamous epithelium, and transitional epithelium.

The first statement is true because the maxilla and ethmoid bones do meet in the lateral wall of the nasal cavity. However, the second statement is false because there is no medial projection called the superior nasal conchae where these bones meet.

All of the above bones are found in the lateral wall of the nasal cavity. The ethmoid bone is a complex bone that forms part of the medial wall and also contributes to the lateral wall of the nasal cavity. The maxilla bone forms the floor of the nasal cavity and contributes to the lateral wall as well. The inferior nasal conchae are scroll-like bones that are located on the lateral wall of the nasal cavity. Therefore, all of these bones are found in the lateral wall of the nasal cavity.

The maxillary lateral incisor would not be found in proximity to the floor of the maxillary sinus. The maxillary sinus is located above the maxillary teeth, and the lateral incisor is positioned between the central incisor and the canine. Therefore, it is not in close proximity to the floor of the maxillary sinus.

The superior anterior opening in the hiatus semilunaris refers to the opening of the frontal sinus. The hiatus semilunaris is a narrow channel in the lateral wall of the nasal cavity, and the superior anterior opening is one of the three openings found in this channel. The frontal sinus is a paired air-filled cavity located in the frontal bone of the skull, and its opening into the nasal cavity is through the superior anterior opening of the hiatus semilunaris.

The exception among the given options is "periodontal pocketing surrounding maxillary molars." This is because periodontal pocketing is a condition related to the gums and teeth, not the sinuses. The other options, such as fluid-filled sinus space, closed off sinus openings, pain in the maxillary molar area, and congestion or clogging in the nose and ear, are all symptoms that can indicate a maxillary sinus infection.

The external nose has bony attachments to the nasal bones and the anterior nasal spine of the maxilla. This means that the external nose is connected to both the nasal bones and the maxilla through bony attachments. Therefore, the correct answer is a and c, which means that the external nose has bony attachments to both the nasal bones and the anterior nasal spine of the maxilla.

The region where the nasal cavity becomes the nasal pharynx is known as the choana and the posterior nasal aperture. The choana is the opening at the back of the nasal cavity that leads into the nasal pharynx, while the posterior nasal aperture is another term used to describe this same region. Therefore, both options "a" and "c" above are correct.

The statement is false because the respiratory epithelium does not have goblet cells with hairlike projections. Goblet cells are specialized cells found in the respiratory tract that secrete mucus to protect and lubricate the airways. They do not have hairlike projections. The hairlike projections in the respiratory tract are actually called cilia, which are present on the surface of certain cells in the respiratory epithelium. Cilia help to move mucus and trapped particles out of the airways.

The paranasal sinuses help to warm the air entering the nasal cavity. This is true because the sinuses are lined with respiratory epithelium, which contains blood vessels that warm the air as it passes through the sinuses. The warm air then enters the nasal cavity, providing a more comfortable breathing experience.