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, 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  af weeks 4-6 Formation of Salivary Glands of development Covered in BMS lecture: ‘Embryology of the head, face and oral cavity’ 4 Types of salivary glands There are three bilateral pairs of major salivary glands: both  Parotid glands sides  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 Largest besides ear - - Paro:d - -  Largest of the major glands  100% serous saliva (watery)  25% of total saliva volume in Oral cavity Position  Below the external auditory meatus = Ear  Between the mastoid process and the posterior border of the ramus 7  has doct. carries saliva from each gland a gland to olecity Duct  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 buccal sulcus papillae. calculus near docts saliva Nerve Innervation controls rate of  Glossopharyngeal (autonomic) production Stensen’s Papillae  Auriculotemporal (sensory)  Intimately associated with the Facial nerve 8  2nd Largest Submandibular  Mixed saliva secretions  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 Sublingual  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 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  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 Epithelium- lines the ducts and produces the saliva. 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 Secretary units 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  (watery 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: viscos - Less watery-thick - binds food to bows  Mucous secretory cells  Have a wider lumen  Produce a viscous mucin rich secretion (mucous saliva)  Functions of mucous saliva include:  Binding food into a bolus  Protect the oral cavity against frictional abrasion  Lubrication 22  Joint/mixed Serous-mucous Acini:  In a mixed serous- mucous acini the serous secretory cell forms a serous demilune around mucous secretory cell 23  musche ↑ Myoepithelial Cells These cells embrace the acini secretory cells, contracDng and squeezing, forcing the saliva out of the lumen and into the ducts 24 Acinar Fluid (not saliva just yet!) Consists of: Water Inorganic Ions Small molecules and products synthesised by cells (mucoproteins and amylase) 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 oral Cavity 26  , a Intercalated Acinar Guid the 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 y  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 D 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 Hyposalivation saliva reduction Can be caused by: Testinia MedicaDons or tablets - Radiotherapy damage - 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  block > - infection of Obstruction gland Caniculi calcium deposits - Calcium deposits formaDon in the ducts. Common in the submandibular glands, it can lead to infecDon or inbammaDon of the gland mucode , round soft movable, , Cysts painless servicleer , , bluish , 2-10 man Trauma to the salivary gland or duct causing an accumulaDon of saliva in FOM the surrounding Dssue. Major Saling  Mucocele- minor glands gland  Ranula- major glands in the boor of the mouth (could be submandibular or sublingual) 33  Irradiation Head and neck irradiaDon destroys the secretory cells (atrophy) and leads to xerostomia. ↳ able no larger salive produce Functions dont always Further reading on oral care following radiotherapy: come back.  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 of saliva Sjögren’s syndrome, an immunological disorder that causes: swelling glands The Body / Oral cavity Frotylthrceea 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 - Smokers 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. hard palate inflammed red burps - - small 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 vomitting - Diabetes Pregnancy Obesity Bi lateral swelling 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 depressant Can you name any medicaDons that contribute to dry mouth? Anti-anxiety - Diretics 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: 40 Additional Resources Journal Ar:cle Contreras-Aguilar M.D. & Gómez-García F. (2020) ‘Salivary Glands’ Anatomy and Physiology’, in Tvarijonaviciute A., Marlnez-Subiela S., López-Jornet P., Lamy E. (ed.) Saliva in Health and Disease. Springer, Cham. h\ps://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) h\ps://youtu.be/gdq8mjsWRkk Other Some good diagrams and images h\ps://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