Functions of the Mouth and Oesophagus Flashcards
(44 cards)
What is the aim of mastication?
to increase SA for digestion
Where does carbohydrate and fat metabolism start?
in the mouth and oropharynx with salivary lipase and amylase
Whats the difference between endocrine and exocrine glands?
endocrine secrete directly into the blood whereas exocrine release into ducts which lead to their target tissues
What do the salivary glands secrete?
- mucous
- fluid
- IgA
- lysozymes
- lactoferrrin
What is the function of IgA, lysozyme and lactoferrin?
antibacterial
What do the acinar cells of the salivary glands produce?
enzymes
What do ductal cells of salivary glands produce and secrete?
- produce mucous in the goblets cells
- secrete water and electrolytes
What are the three types of salivary gland?
parotid
submandibular
sublingual
What are the roles of the secretions?
- lubricates
- hydrates (keeps oral mucosa moist, prevent dehydrations and cell death)
- cytoprotection (protects oral and oesophageal mucosa from damage)
- immune function
How does IgA work?
binds to pathogenic antigens
How does lactoferrin work?
binds iron and is a bactericidal
What is the role of lysozymes?
attack bacterial cell wall
How do the salivary secretions protect from pathogens?
- bind and neutralise toxins
- block viral attachment
- opsonise bacteria
- activate complement
- activate NK cells
- taken up by M cells in the bowel to simulate lymphoblasts and increase IgA secretion
What is the role of salivary duct cells?
- modify secretions of acinar cells
- extracts Na+ and Cl-
- secretes K+ and HCO3-
What are the features of saliva?
hypotonic and alkaline
Why is saliva alkaline?
- protect teeth from bacterial acid
- neuralises gastric acid reflux
Name two salivary gland diseases
Sjogren’s syndrome
mumps virus (parotitis)
(can learn about these on slides)
What source and ganglion parasympathetically innervates the submandibular and sublingual gland and what is the stimulation?
- 7th cranial nerve (facial)
- otic ganglion
- secretion
What source and ganglion parasympathetically innervates the parotid gland and what is the stimulation?
- 9th cranial nerve
- submandibular ganglion
- glossopharyngeal nerve
- secretion
What source and ganglion innervates the glands sympathetically and what is the effect?
- thoracic sympathetics
- vasoconstriction
- thick mucous secretion
What are the four phases of swallowing?
- oral preparatory phase (mastication)
- oral phase (tongue propels food posteriorly until pharyngeal swallow is triggered)
- pharyngeal phase (bolus transported through pharynx with co-ordinated closure of glottis, cessation of breathing and relaxation of oesophageal sphincter)
- oesophageal phase (peristalsis moves bolus to lower oesophageal sphincter)
What nerves cause swallowing?
- centre in medulla
- trigeminal nerve (V)
- glossopharanygeal nerve (IX)
- Vagus (X)
- hypoglossal (XII)
Swallowing diseases?
pseudo bulbar and bulbar palsies
Symptoms of swallowing diseases?
- difficulty swallowing
- altered speech
- loss of gag reflex
