L03 - Functions of the mouth/ oesoph and ass diseases Flashcards
What are the function of acinar cells?
Exocrine glands producing enzymes
e.g. a amylase
What are the function of ductal cells?
- Produces mucous (goblet cells)
- Secrete water and electrolytes
- Stimulated by hormone secretin
What is the total approx vol of liquid secreted from mouth per 24 hours?
1.5L
What is the histological type/ type of secretion/ % of total secretion from the parotid gland?
- Serous
- Water
- 20%
What is the histological type/ type of secretion/ % of total secretion from the submandibular gland?
- Mixed
- Viscous
- 70% (majority)
What is the histological type/ type of secretion/ % of total secretion from the sublingual gland?
- Mucous
- More viscous than submandibular secretion
- 10%
Why is saliva needed?
- Lubrication
- Hydration
- Keeps the oral mucosa moist and prevents dehydration and cell death - Cytoprotection
- Protects oral and oesophageal mucosa from damage - Immune function
- Antibacterial properties
- Salivary secretions play an important role in protection from pathogens
Which enzymes can be found in saliva have serve an immune function?
- IgA
- IgA antibodies bind to pathogenic antigens - Lactoferrin
- Binds iron and is bactericidal - Lysozyme
- Attacks bacterial cell wall (cell lysis)
Why does saliva need to be alkaline?
- Protects teeth from bacterial acid
2. Neutralises gastric acid that refluxes into the oesophagus
How do salivary duct cells affect secretions of acinar cells?
Salivary duct cells modify the secretion of acinar cells:
- Extracts Na+ amd Cl-
- Secretes K+ and HCO3-
=> Therefore saliva is hypotonic and alkaline
What is Sjogrens syndrome?
- AI attack of salivary and tear glands which results in dry mouth and eyes (xerostomia - dry mouth)
- Commonly affects women, assoc with RA
- ANA (anti-nuclear antibody) and rheumatoid factor
What is mumps virus (patotitis)?
- Prodrome of headache and fever
- Assoc with orchitis (inflammation of testicles)
- MMR vaccine available
- Swelling of parotid glands
What is the innervation of the salivary glands (general)
ANS controls secretion
- Predominantly via the parasympathetic NS
Which glands does the parasympathetic NS innervate? (and which ganglion)
CN VII –> Submandibular and sublingual [submandibular ganglion]
CN 1X –> Parotid [otic ganglion]
Effect of stimulus –> secretion
Which glands does the sympathetic NS innervate? (and which ganglion)
Thoracic sympathetics –> ALL salivary glands [superior cervical ganglion]
Effect of stimulus –> vasoconstriction
–> thick mucous secretion
What are the 4 phases to swallowing?
- Oral preparatory phase
- Oral phase
- Pharyngeal phase
- Oesophageal phase
What happens in the oral preparatory phase of swallowing?
Food is manipulated in the mouth and masticated to reduce to a consistency which can be swallowed
What happens in the oral phase of swallowing?
The tongue propels food posteriorly until the phrayngeal swallow (reflex) is triggered
What happens in the pharyngeal phase of swallowing?
Once the pharyngeal swallow is triggered, the bolus is transported through the pharynx
- WITH co-ordinated closure of the glottis via movement of the epiglottis
- AND cessation of breathing
- AND relaxation of the upper oesophageal sphincter (UOS)`
What happens in the oesophageal phase of swallowing?
- Oesophageal peristalsis carries the bolus from the cricopharyngeal juncture (the UOS)` through the oesophagus to the LOS
What is the pharyngeal swallow?
- A reflex
- Coordinated by the swallowing centre on the medulla oblongata and pons (CN V, IX, X, XII)
- Initiated by touch receptors in the pharynx as bolus is pushed to the back of the mouth by the tongue
- OR by stimulation of palate (palatal reflex)
What is pseudobulbar palsy?
- Inability to control facial movements (such as chewing and speaking)
- Upper motor neurone (i.e. pre ganglionic)
What is bulbar palsy?
- Impairment of function of the CN IX, X, XI and XII
- Lower motor neurone (i.e. post ganglionic)
- Lesion in the medulla oblongata or from lesions of the lower CN outside the brain stem
Where is the anatomical site for pseudobulbar palsy?
- Cerebral cortex fibres pass to the medulla via corticobulbar pathway in pyramidal tract
