Physiology of the Salivary Glands
John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford in Head & Neck Surgery Plastic Surgery, 2018
The production of saliva is an active process occurring in two phases: Primary secretion is produced by the acinar cells and is an active process; the result is a product similar in composition and osmolality to plasma.The primary secretion is then modified as it passes down the ductal system, again by active processes occurring in the cells lining the duct. Broadly, as the primary secretion passes down the duct the primary secretion becomes progressively more hypotonic with decreased sodium and increased potassium concentrations. In general, saliva comprises 99.5% water, in addition to proteins, glycoproteins and electrolytes. The saliva is high in potassium (7 x that of plasma), low in sodium (1/10 x that of plasma,) calcium, phosphorous, chloride, thiocyanate, and urea resulting in a pH of 5.6–7.4
The salivary glands
Neeraj Sethi, R. James A. England, Neil de Zoysa in Head, Neck and Thyroid Surgery, 2020
The functions of saliva are: Lubrication (essential for speech, mastication and swallowing)Buffering and clearance of acids (due to slightly alkaline pH)Maintenance of tooth integrity (by influencing mineralisation, demineralisation and remineralisation)Antibacterial activityTasteDigestion (salivary amylase initiates digestion of carbohydrates) [4]
The patient’s mouth is dry
Wesley C Finegan in Being a Cancer Patient’s Carer, 2018
Having a dry mouth is a nuisance, but there is much more to it than just nuisance value. Saliva has several functions including: Keeping our mouths moist, allowing our lips and tongue to move around without getting stuck to the roof of our mouth and our teeth. Saliva also helps to provide a slight suction, which helps to hold a denture in place.Allowing us to speak clearly.Adding calcium to our teeth. Calcium is essential for healthy teeth, helping to reduce decay, especially round the margins of our gums, which become very vulnerable if our mouths are dry.Moistening and softening our food and helping us to appreciate its taste.Neutralising the acids that form in our mouths after we eat food. These acids attack the enamel surfaces of the teeth, then bacteria cause decay in the damaged surfaces.An antiseptic action that helps to kill the bacteria that cause decay.
Effects of hemodialysis treatment on saliva flow rate and saliva composition during in-center maintenance dialysis: a cross-sectional study
Published in Renal Failure, 2021
I-Chen Yu, Chieh-Yu Liu, Ji-Tseng Fang
Saliva comprises numerous substances. In addition to water and mucin, saliva contains blood urea nitrogen (BUN), creatinine (Cr), and various electrolytes. Relevant research has indicated that the concentrations of biochemical substances in saliva and blood are equally correlated to each other [6]. The saliva secretion volume under normal physiological functioning should be approximately 0.5–1 L/day [7]. A survey conducted in Taiwan indicated that the unstimulated saliva flow rate of hemodialysis patients is approximately 0.06–0.07 mL/min [8]; approximately 66.4% of such patients have experienced dry mouth [9]. Ship et al. determined that unstimulated saliva flow rate below 0.1–0.2 mL/min indicates salivary gland hypofunction (SGH) [10]. Using salivary scintigraphy, Kao et al. found hemodialysis patients who experienced dry mouth had decreased salivary gland functioning [11]. A possible reason underlying the occurrence of dry mouth in dialysis patients is metabolic wastes, such as high concentration BUN and Cr, damaging the salivary gland; this in turn affects the saliva secretion function of the gland and causes the sensation of mouth dryness.
Salivary VEGF and post-extraction wound healing in type 2 diabetic immediate denture wearers
Published in Acta Odontologica Scandinavica, 2022
Katarina Radović, Božidar Brković, Jelena Roganović, Jugoslav Ilić, Aleksandra Milić Lemić, Boris Jovanović
Post-extraction wound healing is an integrative complex of cellular and molecular processes consisted of the following stages: hemostasis, inflammation, proliferative phase and bone tissue remodelling. This is achieved via the time-dependent interplay of cytokines and growth factors, activation of signalling pathways and modulation of genes creating a healing milieu [1]. Vascular endothelial factor (VEGF) is produced by many cell types that participate in wound healing: endothelial cells, fibroblasts, smooth muscle cells, platelets, neutrophils, and macrophages [2–4]. Local hypoxia caused by interruption of circulation due to injury is the primary stimulus for VEGF formation. The most important role of VEGF in the regulation of angiogenesis and growth of granulation tissue in the wound, thus providing oxygenation and nutrition of damaged tissues with the deposition of the fibrin network necessary for wound healing [5]. Wounds in the oral cavity heal faster, with fewer scars than wounds in other parts of the body. The main factor that contributed to this phenomenon is saliva. Saliva promotes the healing of oral wounds by creating a humid environment, which improves the functioning of inflammatory cells crucial for wound healing, and contains a variety of growth factors involved in the various stages of intraoral wound healing. For instance, the proliferation of epithelial cells is promoted by growth factors in saliva, such as VEGF, which exhibit up to three times higher concentrations in saliva than in plasma [6].
Saliva as a diagnostic tool for dental caries, periodontal disease and cancer: is there a need for more biomarkers?
Published in Expert Review of Molecular Diagnostics, 2020
Marília Afonso Rabelo Buzalaf, Adriana de Cássia Ortiz, Thamyris Souza Carvalho, Simone Ortiz Moura Fideles, Tamara Teodoro Araújo, Samanta Mascarenhas Moraes, Nathalia Rabelo Buzalaf, Fernanda Navas Reis
Human saliva is a complex and dynamic biological fluid formed by the secretions of the major salivary glands (parotid, submandibular and sublingual), minor salivary glands present in the buccal mucosa and gingival crevicular fluid [4]. Saliva has many functions and participates in several biological processes such as defense, tissue lubrication, chewing, swallowing, taste, digestion and cleaning of foods, debris and microorganisms of oral cavity. In addition, saliva is the main biological factor involved in the protection of the teeth against demineralization. Due to its buffering capacity, saliva dilutes and neutralizes the acids from the diet and bacterial metabolism of the biofilm [4,5]. Saliva also acts on the formation of the acquired enamel pellicle, which represents a protection barrier for the teeth against mineral loss [4,6]. The biochemical composition of saliva, which is supersaturated in relation to hydroxyapatite, minimizes demineralization and favors remineralization of dental tissues during pH variations that occur in the oral environment. Thus, saliva plays an important role in maintaining tooth integrity and oral cavity homeostasis [4,5].
Related Knowledge Centers
- DNA
- Enzyme
- Epithelium
- Extracellular Fluid
- Lipase
- Mouth
- Mucus
- White Blood Cell
- Salivary Gland
- Electrolyte