Functions of Mouth/oesophagus and associated diseases Flashcards
What are the functions of mouth and oropharynx?
- Chewing food- mastication -increases S.A.
- Initiation of carbohydrate and fat metabolism- salivary amylase and lipase
- Lubrication
What is the function of oesophagus?
conduit
What does salivary glands contain?
exocrine glands
secretory organs
What does exocrine glands secrete?
amylase
lipase
What does secretary organs secrete?
- Mucous
- Fluid
- IgA
- Lysozyme
- Lactoferrin
What cells does salivary glands contain?
What is the total volume of secretion by salivary glands per 24 hrs?
1.5 L
What does parotid gland secrete?
Water. Serous histologic type. 20 % of total secretion
Describe the type of saliva produced by each salivary gland. Which salivary gland produces saliva in the greatest volume?
Parotid - serous cells, water
Submandibular - mixed cells, slightly viscous
Sublingual - mucous cells, very viscous
greatest volume = submandibular
What does submandibular gland secrete?
Viscous secretion. Mixed histologic type. 70 % total secretion
What does sublingual gland secrete?
Very viscous secretion. Mucous histologic type . 10 % total secretion
What is the function of salivary glands?
Lubrication Hydration- keeps oral mucosa moist and prevents dehydration and cell death Cytoprotection- protects oral and oesophageal mucosa from damage
What is the role of IgA in immune function
IgA antibodies bind to pathogenic antigen
Bind and neutralise protein toxin
Block attachment of virus to cells
Opsonize bacteria
Activate complement
Activate NK cells
Taken up by M cells in the bowel to stimulate lymphoblasts and subsequent secretion of more IgA
What is the role of Lactoferrin on immune function
binds iron and is bactericidal
What is the role of lysozyme on immune function
attacks bacterial cell wall - cell lysis
What is the function of salivary duct?
Salivary duct cells modify the secretion of acinar cells:
extracts Na+ and Cl-
secretes K+ and HCO3-
Saliva is therefore hypotonic and alkaline
What is the purpose of alkaline saliva?
Protects teeth from bacterial acid
neutralises gastric acid that refluxes into the oesophagus
What is Sjogrens sysndrome?
Autoimmune attack of salivary and tear glands which results in dry mouth and eyes
Who does Sjogren’s commonly affect?
women, associated with rheumatoid factor
What is Xerostomia?
dry mouth and eyes
What are the diagnostic tests for Sjogren’s?
ANA and rheumatoid factor
What are the symptoms of Mumps virus- parotitis?
Prodrome of headache and fever
painful swelling on one or both sides of face
What is mumps virus associated with?
orchitis- inflammation of testicles
How is Mumps prevented?
MMR vaccine
How is salivary glands secretion controlled predominantly?
Autonomic nervous system- predominantly via parasympathetic
Which nerves are involved in the parasympathetic control of secretion?
VIIth cranial nerve- facial nerve
IXth cranial nerve- glossopharybgeal nerve
What is the effect of VIIth cranial nerve of secretion?
secretion of submandibular and sublingual gland
What ganglion does the VIIth cranial nerve pass through before innervating the submandibular and sublingual gland?
Submandibular gland
What is the effect of IXth cranial nerve on secretion?
secretion of parotid gland
What ganglion does the IXth cranial nerve pass through before innervating the parotid gland?
Otic ganglion
What the source of sympathetic innervation for salivary glands secretion
Thoracic sympathetics
What is the effect of thoracic sympathetics stimulation
Thick mucous secretion of all glands. Vasocontriction
What are the 4 phases involved in swallowing?
- Oral Preparatory Phase - food is manipulated in the mouth and masticated (chewed) to reduce to a consistency which can be swallowed
- Oral Phase - the tongue propels food posteriorly until the pharyngeal swallow is triggered
-
Pharyngeal Phase - 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)
- Oesophageal Phase - oesophageal peristalsis carries the bolus from the cricopharyngeal juncture (the UOS) through the oesophagus to the Lower oesophageal Sphincter (LOS)
What happens in Oral preparatory phase?
food is manipulated in the mouth and masticated to reduce to a consistancy which can be swallowed
What happens in Oral phase?
the tongue propels food posteriorly until the pharyngeal swallow is triggered
What happens in Pharyngeal phase?
Once the pharyngeal swallow is triggered , the bolus is transported through the pharynx
Co-ordinated closure of glottis via movement of the epiglottis
cessation of breathing
relaxation of the UOS
What happens in Oesophageal phase?
Oesophageal peristalsis
Bolus from UOS to LOS
How is swallowing controlled?
Swallowing centre in medulla
Which nerves are involved in the swallowing centre in medulla
Trigeminal (V) Glossopharyngeal (IX) Vagus (X) Hypoglossal (XII)
What are the layers in oseophagus, from inner to outer?
Mucosa
Submucosa
meissners, submucosal plexus
Inner circular muscle
Myenteric plexus
Outer longitudinal muscle NO serosa NO mesentery
Histology of Oesophagus
Stratified squamous to GOJ- Z line
Oesophagus embryology
the trachea develops as lung buds from the oesophagus
as development progresses, the trachea matures and lies anterior to oesophagus
What are the congenital problems involving oesophagus?
Tracheoesophageal fistula- oseophagus joins the trachea
Oesophageal atresia- oesophagus closing off
What are involved in the physiological maintenance of GOS competance?
Lower Oesophageal sphincter tone intra-abdominal length of oesophagus
What is involved in the maintenance of LOS tone?
CCK, gastrin, vagal stimulation
Pathology of LOS tone
effects of proximal vagotomy loss of CCK in pregnancy
