Tag Archives: ent

Paranasal sinuses and sinus conditions

The videos on this page can be downloaded upon purchase of a license on Alila Medical Media website. Click here!


Paranasal sinuses, or simply “sinuses” in common language,  are air cavities in the bones of the skull. There are four pairs of sinuses (see Fig. 1, 2 and upper panel of Fig. 3):

– the maxillary sinuses are under the eyes, in the maxillary bones.
– the frontal sinuses are above the eyes, in the frontal bone.
– the ethmoid sinuses are between the nose and the eyes, in the ethmoid bone.
– the sphenoid sinuses are behind the nasal cavity, in the sphenoid bones.

Sinusitis
Fig.1: The four pairs of sinuses. Red = frontal, green =  ethmoid, blue = sphenoid, beige =  maxillary. The right panel show normal sinuses on half of the head and inflamed sinuses on the other half. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

The sinuses are lined with respiratory epithelium producing mucus. The mucus drains into nasal cavity through small openings (Fig. 2 left panel, Fig. 3 upper panel). Impaired sinus drainage has been associated with inflammation of sinuses (sinusitis, see below).
Biological function of the sinuses remains unclear.

Nose anatomy labeled. .
Fig. 2: Front view of the sinuses (left panel) showing connections to the nasal cavity. Right panel shows mid-sagittal section of the head. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

 

Sinusitis or rhinosinusitis is inflammation of the paranasal sinuses (Fig. 1, right panel). This can be due to:
– allergy (allergic rhinitis): allergens such as pollen, pet dander,.. trigger overreaction of the mucosa of the nose and sinuses resulting in excess mucus, nasal congestion, sneezing and itching.
– infection: usually as a complication of an earlier viral infection of the nasal mucosa, pharynx or tonsils such as during a common cold. Impaired sinus drainage due to inflammation of nasal mucosa during a cold often leads to infection of the sinus itself. Cold-like symptoms plus headache and facial pain/pressure are common complaints.
– other conditions that cause blockage of sinus drainage: structural abnormality such as deviated nasal septum (Fig. 3); formation of nasal polyps (Fig. 4). When a sinus is blocked, fluid builds up making it a favorable environment for bacteria, viruses or fungi to grow and cause infection.
Deviated nasal septum
Fig. 3: Front view of the sinuses (upper panel) showing connections to the nasal cavity, also shown the nasal septum (light blue color). Lower panel shows deviated septum blocking drainage of the right maxillary sinus (your left). Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

 

 

 

Nasal polyps

Fig. 4: Nasal polyps – overgrowths of nasal mucosa – block sinus drainage. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

 

 

Treatment depends on the cause of sinusitis:
– For viral infection : symptom relief medications such as nasal spray for irrigation and decongestion; other conservative treatment for common cold such as rest and drinking plenty of fluid.
– For bacterial infection: antibiotics may be prescribed.
– For allergy: intranasal corticosteroids are commonly used.
– For recurrent (chronic) sinusitis due to structural abnormalities or nasal polyps, nasal surgery may be recommended.

                                                                                                           See all Respiratory topics

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Swallowing and Dysphagia (with Animation)

Swallowing

Below is a narrated animation about swallowing reflex, phases and overview of neural control. Click here to license this video on Alila Medical Media website.

Swallowing, or deglutition, is the process by which food passes from the mouth, through the pharynx and into the esophagus. As simple as it might seem to healthy people, swallowing is actually a very complex action that requires an extremely precise coordination with breathing since both of these processes share the same entrance: the pharynx. Failure to coordinate would result in choking or pulmonary aspiration. Swallowing involves over twenty muscles of the mouth, throat and esophagus that are controlled by several cortical areas and by the swallowing centers in the brainstem. The brain communicates with the muscles through several cranial nerves.

Swallowing consists of three phases

1. Oral or buccal phase: this is the voluntary part of swallowing, the food is moistened with saliva and chewed, food bolus is formed and the tongue  pushes it to the back of the throat (pharynx). This process is under neural control of several areas of cerebral cortex including the motor cortex.
2. Pharyngeal phase starts with stimulation of tactile receptors in the oropharynx by the food bolus. The swallow reflex is initiated and is under involuntary neuromuscular control. The following actions are taken to ensure the passage of food or drink into the esophagus:
– The tongue blocks the oral cavity to prevent going back to the mouth.
– The soft palate blocks entry to the nasal cavity.
– The vocal folds close to protect the airway to the lungs.The larynx is pulled up with the epiglottis flipping over covering the entry to the trachea (the windpipe). This is the most important step since entry of food or drink into the lungs may potentially be life threatening.
– The upper esophageal sphincter (UES) opens to allow passage to the esophagus.
3. Esophageal phasefood bolus is propelled down the esophagus by peristalsis – a wave of muscular contraction that pushes the bolus ahead of it. The larynx moves down back to original position.

Click here to see an animation of the swallowing process on on Alila Medical Media website where the video is also available for licensing.
Swallowing, labeled
Fig. 1: Anatomy of swallowing. See text for details of phases. The blue arrows represent breathed air. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

 

Dysphagia (swallowing disorders)


This  video is available for licensing on Alila Medical Media website. Click HERE!

Dysphagia refers to a group of conditions characterized by difficulty swallowing. There are two main classes of problems that can lead to swallowing disorders:


 1. 
Neuromuscular problems: 

– Muscular disorders that affect skeletal muscles, such as muscular dystrophy, myasthenia gravis…

– Diseases of the nervous system that compromise the way the brain controls the swallowing reflex, such as stroke, Parkinson’s disease, multiple sclerosis…

Weakened muscles and/or impaired coordination as a result of aging.

This class commonly affects the first two phases of swallowing.

2. Narrowing of the throat or esophagus due to throat cancer, esophageal cancer and formation of small sacs or rings in the walls of the esophagus.  Gastroesophageal reflux disease – GERD – is also a common cause. In GERD, scars resulted from stomach acid injuries may obstruct the esophagus and cause difficulty swallowing.

This class mostly affects the third phase of swallowing.

Schatzki ring blocks esophagus
Fig. 2: Schatzki ring makes the lumen of esophagus smaller. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.

 

 

 

For people with dysphagia, eating becomes a challenge. The consequences may be serious. Someone who cannot swallow safely is at high risks of choking, pulmonary aspiration and may not be able to eat enough to stay healthy.

Treatment depends on the cause of the condition:

– Muscle strength and coordination exercises may be recommended for some.

– A change in the position of the head and neck when eating could be beneficial to others.

– Right choice of food and drink is important for most. Soft textured food and thickened drinks are recommended for safe swallowing.

– Surgery may be needed to remove narrowed parts of the esophagus.

– Finally, patients with severe dysphagia and recurrent aspiration may have to resort to tube feeding to get nutrition to the body.

                                                                                                                            See all ENT topics

                                                                                                                    See all Digestive topics

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Oral Cavity Gallery

Download illustrations of permanent and deciduous dentition, tooth anatomy, periodontal diseases, teeth replacement therapy, mouth anatomy and diseases.

Please note: Free downloads are intended to facilitate healthcare education for people in need in low income countries and can be used for educational purposes only. If you can afford it or if you plan to use the images for commercial purposes, please consider buying instead. You can find a larger image collection at higher resolution for sale at affordable prices on Alila Medical Media website.

To download: right click on full size image – choose “Save image as” and save it into your computer. By downloading from this website you acknowledge that you agree to our Conditions of Use.
To purchase larger sizes of the image: (left) click on full size image.

Tooth anatomy, unlabeled diagram.
Tooth anatomy, unlabeled diagram.
Tooth anatomy from outside and in cross section, unlabeled drawing.
Tooth anatomy, labeled diagram.
Tooth anatomy, labeled diagram.
Tooth anatomy from outside and in cross section, labeled drawing.
Dental checkup icon
Dental checkup icon
Magnifying glass on a molar tooth, illustration.
Plaque and tooth decay, medical drawing.
Plaque and tooth decay, medical drawing.
Tooth decay stages diagram.
Periodontal Disease, labeled diagram.
Periodontal Disease, labeled diagram.
Gum disease stages, from gingivitis to periodontitis.
Adult dentition, medical drawing.
Adult dentition, medical drawing.
Permanent teeth, adult dentition, upper and lower jaws, unlabeled.
Deciduous dentition, medical drawing.
Deciduous dentition, medical drawing.
Deciduous dentition (baby or milk teeth), upper and lower jaws, medical illustration unlabeled..
Head anatomy median section, medical drawing.
Head anatomy median section, medical drawing.
Median section of human head diagram with details of brain, sinuses, tonsils, oral and nasal cavity, pharynx and larynx, unlabeled.
Mouth and throat anatomy, medical drawing.
Mouth and throat anatomy, medical drawing.
Diagram of human oral cavity with denture, tonsils, unlabeled.


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Ear, Hearing Gallery

Download medical drawings of human ear and cochlea anatomy, auditory pathway and mechanism of hearing, middle ear infection.

Please note: Free downloads are intended to facilitate healthcare education for people in need in low income countries and can be used for educational purposes only. If you can afford it or if you plan to use the images for commercial purposes, please consider buying instead. You can find a larger image collection at higher resolutions for sale at affordable prices on Alila Medical Media website.

To download: right click on full size image – choose “Save image as” and save it into your computer. By downloading from this website you acknowledge that you agree to our Conditions of Use.
To purchase larger sizes of the image: (left) click on full size image.

Ear anatomy, labeled diagram.
Ear anatomy, labeled diagram.
Human ear anatomy showing outer, middle and inner ear, eardrum, ossicles and cochlea, labeled drawing.
Ear anatomy, unlabeled diagram.
Ear anatomy, unlabeled diagram.
Human ear anatomy showing outer, middle and inner ear, eardrum, ossicles and cochlea, unlabeled drawing.
Middle ear infection, unlabeled diagram.
Middle ear infection, unlabeled diagram.
Otitis media diagram - infection of the middle ear, a common condition in children, unlabeled.
Middle ear infection, labeled diagram.
Middle ear infection, labeled diagram.
Otitis media diagram - infection of the middle ear, a common condition in children, labeled.
Outer ear infection, labeled diagram.
Outer ear infection, labeled diagram.
Illustration of Swimmer's ear - inflammation of outer ear canal.
Hearing mechanism, unlabeled diagram.
Hearing mechanism, unlabeled diagram.
Diagram showing how sound waves are transmitted and converted into vibration along the basilar membrane, the cochlea is straightened to simplify.
Hearing mechanism, labeled diagram.
Hearing mechanism, labeled diagram.
Diagram showing how sound waves are transmitted and converted into vibration along the basilar membrane, the cochlea is straightened to simplify.


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