Salivary Glands PDF

Salivary Glands [Oral and Dental Sciences] Miss H Rogers GDC ILOs  1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management  1.1.6 Describe relevant and appropriate physiology and explain its application to...

Salivary Glands [Oral and Dental Sciences] Miss H Rogers GDC ILOs  1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management  1.1.6 Describe relevant and appropriate physiology and explain its application to patient management Related topics:  Embryology  Saliva & Salivation  Xerostomia  Skull  Regional anatomy  Extra-oral examination Aim To gain an overview of the salivary glands including their positioning, histology and function Learning Outcomes By the end of this lecture you should be able to: 1. List the major salivary glands 2. Describe the each salivary glands’ positioning, -nerve associated duct, saliva production and innervation 3. Describe the histological structure of a salivary gland 4. Outline the disorders that may affect salivary glands 3  Formation of Salivary Glands Covered in BMS lecture: ‘Embryology of the head, face and oral cavity’ · occurs in first 4-6. Weeks of Development 4 Types of salivary glands sides - Both There are three bilateral pairs of major salivary glands:  Parotid glands  Submandibular glands  Sublingual glands …and numerous minor salivary glands The major salivary glands produce 90% of the total salivary volume 5 Major Salivary Glands 6  the -Besider Paro:d  Largest of the major glands  100% serous saliva -watery saliva  25% of total saliva volume Position  Below the external auditory meatus ear  Between the mastoid process and the posterior border of the ramus O 7  oral cavity. into Saliva Duct carry -  Stensen’s or Parotid Duct  5cm long  Runs from the gland outside the masseter muscle parallel to, and 1cm below, the zygomatic arch.  Pierces the buccinator muscle opening into the oral cavity via the Stensen’s papillae. Adjacent to upper molars. Nerve Innervation  Glossopharyngeal (autonomic) Stensen’s Papillae  Auriculotemporal (sensory)  Intimately associated with the Facial nerve 8  Second largest gland Submandibular Gland  Mixed saliva secretions serous & mucous Salivaa.  Half the size of the parotid gland (walnut size)  60-65% of total saliva volume Position  Between the body of the mandible and the mylohyoid muscle, in the submandibular fossa 9  Duct  Wharton’s duct  5cm long  Opens under the anterior part of the tongue, lateral to the lingual fraenum at the sublingual caruncle Nerve Innervation  Chorda tympani  Lingual branch of the inferior dental nerve 10  smallest major gland Sublingual Gland.  60% mucous saliva  Smallest of the major salivary glands (almond size)  5-10% of total saliva volume Position  Floor of the mouth in the sublingual fossa 11  Duct  Bartholin’s duct  10-20 smaller ducts (Rivinus ducts) open along the sublingual fold Nerve Innervation  Same as the submandibular gland Chorda · tympani Brach of the · Lingual interior dental nerve. 12 13 New Discovery! The Tubarial Glands Located in the nasopharynx. Literature suggests that it may contain a large number of seromucous acini, playing a role in nasopharynx/oropharynx lubrication and swallowing. 14 Minor Salivary Glands 15  Minor SalivaryGlands. Mixed saliva, predominately mucous Produce lots of salivary proteins >10% of the total saliva volume Named according to where they are found e.g. buccal or labial salivary glands To read more on the individual minor salivary glands, have a look at SecDon 2 in Gupta, S. & Ahuja,N. (2019) Salivary Glands. 16 Salivary Gland Structure 17  made up off ⑧ Epithelium- lines the ducts and produces the saliva. ⑧ Connec:ve :ssue- surrounds the epithelium, protecDng and supporDng the gland. The connecDve Dssue is divided into: the capsule (which surrounds the enDre outer porDon of the gland) the septum [plural, septa] (which divides the inner porDon of the gland into lobes and smaller lobules). The capsule and septa carry the nerve and blood supply to the cells. 18 Adenomeres An adenomere is the working part of a salivary gland and is surrounded by connecDve Dssue 19 Acini Within the adenomere are secretory units (acini) which are made up of secretory cells. Their base is resDng against the surrounding connecDve Dssue (supplying nerves and blood to the cells). The acini are classiQed into:  Mucous acini  Serous acini …or a mixture of both! 20  Serous Acini:  Serous secretory cells  Produce a watery serous secretion (serous saliva)  Functions of serous saliva include:  Lubricating food  Enzymic action begins digestion  Removing epithelial debris  Diluting food 21 Mucous Acini:  Mucous secretory cells  Have a wider lumen  Produce a viscous Thick - mucin rich secretion (mucous saliva)  Functions of mucous saliva include:  Binding food into a bolus Ready to swallow ·.  Protect the oral cavity against frictional abrasion  Lubrication 22  Serous-mucous Acini:  In a mixed serous- mucous acini the serous secretory cell forms a serous demilune around mucous secretory cell 23  a -aroundiniti Myoepithelial Cells These cells embrace the acini secretory cells, contracDng and squeezing, forcing the saliva out of the lumen and into the ducts Sal not i rae nd 24 Acinar Fluid (not saliva just yet!) Consists of: Water Inorganic Ions Small molecules and products synthesised by cells (mucoproteins and amylase) collects Stuff as moves through ducts. 25  Ducts Following the secretory end piece are ducts along which the saliva travels and becomes further modiQed via resorpDon. There are three types of duct:  Intercalated  Striated  Excretory 26 Intercalated Lined by a single layer of cuboidal epithelial cells Striated  This makes up the bulk of the duct system.  Lined with a single layer of columnar epithelial cells characterised by basal striaDons  This aids in the modiQcaDon of the saliva 27 Excretory (terminal)  Or the secretory duct  Saliva exits into the oral cavity via this duct  Lined by pseudostraDQed columnar epithelium which then changes to straDQed cuboidal and then Qnally straDQed squamous epithelium at its opening 28 Supporting Images 29 Blood Supply Supplied by the external caroDd artery (plus facial and lingual artery), with vessels (and nerves) entering the gland at the hilum There are two capillary networks, one for the secretory end piece and one for the ducts Control of saliva:on Salivary nuclei in the brain are sDmulated by taste, smells, thoughts etc These trigger neurotransmi\er release from nerve endings of salivary glands Click here for an interacDve microscopic image of salivary gland Dssue. 30 Disorders of the Salivary Glands 31  of Reduction Hyposalivation - Saliva. Can be caused by: MedicaDons or tablets Radiotherapy Autoimmune diseases Diabetes Salivary stones (can cause severe pain when eaDng) Which of these cause reversible and which cause irreversible e`ects? The Cracker Challenge- how it feels to have a dry mouth 32 Obstruction Caniculi Saliva Stone - Calcium deposits formaDon in the ducts. Common in the submandibular glands, it can lead to infecDon or inbammaDon of the gland cocele mu · moveable painless Cysts · Dome snapped. Trauma to the salivary gland or duct 2-10mm causing an accumulaDon of saliva in mouth the surrounding Dssue. floor of.  Mucocele- minor glands  Ranula- major glands in the boor of the mouth (could be - Reter Ranula. it seen submandibular or sublingual) 33  Irradiation Head and neck irradiaDon destroys the secretory cells (atrophy) and leads to xerostomia. Sometimes reversible after TX finishes Further reading on oral care following radiotherapy:  Devi, S., and Singh, N. (2014) Dental care during and aRer radiotherapy in head and neck cancer  Cancer Research UK  Mouth Care Founda:on 34 Degenerative - autoimmune disorder Sjögren’s syndrome, an immunological disorder that causes: The Body Oral cavity Dry eyes Mild erythema and thinning Acini destroyed of the mucosa Change in lachrymal Erythema, Qssuring, coaDng apparatus and depapillaDon of the dorsum of the tongue Rheumatoid arthriDs is oden TraumaDc erosions and associated ulcers, angular cheliDs and Raynaud phenomenon chapped lips Frothy, ropey and thickened saliva For more informaDon, click here 35 Inflammation/Infection Mumps An acute viral infecDon causing inbammaDon and painful swelling of the paroDd glands For more informaDon on mumps, click here Nico:ne Stoma::s Caused by inbammaDon of the minor salivary glands located on the palate in response to heat from tobacco use. The duct openings become dilated and can appear as red dots. 36 Sialosis A painless swelling of the paroDd glands, not caused by inbammaDon or infecDon. Can occur on its own but may also appear as a result of other medical condiDons, examples include: Liver cirrhosis Bulimia Diabetes Pregnancy Obesity Kidney failure For more informaDon: The BriDsh & Irish Society for Oral Medicine 37 Neoplasms (tumours) These can be: Benign Malignant E.g. Warthin’s tumour E.g. Salivary gland carcinoma Bilateral Warthin’s tumour- click Click here to read the here to read the case study case study Pleomorphic adenoma Acinic cell carcinoma Click here to read the Click here to read the case study case study 38 Functional Disorders Dry mouth caused by:  EmoDonal disturbances e.g. anxiety  Mouth breathing  Smoking  Drugs Can you name any medicaDons that contribute to dry mouth? anti anxiety Drepression medication 39 Summary With so many condiDons potenDally impacDng on the salivary glands, it is important that they are included on our extra-oral examinaDon. AcDvity: Complete Salivary gland Position the table below, Duct or % of total create saliva volume your Innervation own, detailing each of the salivary glands covered in this lecture: next e on pag 40 Salivary Glands- Summary With so many condi.ons poten.ally impac.ng on the salivary glands, it is important that they are included on our extra-oral examina.on. Ac.vity: Complete the table below, or create your own, detailing each of the salivary glands covered in the lecture: % of total saliva Salivary gland Posi/on Duct Innerva/on Below the ear and volume Glossopharangeal Between the mastoid Stensens / parotid 25% Auriculotemporal Parotid gland Process and border of Duct Serous saliva Facial nerve Ramus Between body of the Chorda tympani Submandibular Mandible and mylohoid 60-65% Lingual branch of Muscle. Submandibular Whartons duct Gland Fossa Mixed saliva Inferior dental nerve 5-10% Chorda tympani Floor of mouth in Barthollins duct Sublingual gland Mucosa saliva Lingual branch of The sublingual fossa Inferior dental nerve Named according to Less than 10% Minor saliva glands Where they are found Mixed saliva Eg buccal, lingual Additional Resources Journal Ar*cle Contreras-Aguilar M.D. & Gómez-García F. (2020) ‘Salivary Glands’ Anatomy and Physiology’, in Tvarijonaviciute A., MarJnez-Subiela S., López-Jornet P., Lamy E. (ed.) Saliva in Health and Disease. Springer, Cham. hPps://doi.org/10.1007/978-3-030-37681-9_1 Online Book Gupta, S. & Ahuja, N. (2019). ‘Salivary Glands’, in Heinbockel, T. & Shields, V. (ed.) Histology. IntechOpen. DOI:10.5772/intechopen.81213. YouTube Ninja Nerd Lecture- Gastrointestinal | Salivation: Parotid, Submandibular, & Sublingual Glands https://www.youtube.com/watch?v=3tasuHt6jKg  Sam Webster- Salivary glands (anatomy) hPps://youtu.be/gdq8mjsWRkk Other Some good diagrams and images hPps://www.slideshare.net/upamasishan/salivary-glands-51253694 41 References Bath-Balogh, M., and Fehrenbach, M.J,. (2006) Dental embryology, histology, and anatomy. 2nd Ed. Elsevier. Waugh, A., and Grant, A. (2006) Anatomy and physiology in health and illness. 10th Ed. Elsevier. 42 Any Questions? Email [email protected] 43