Salivation Swallowing Flashcards
What is the composition of saliva ?
Water (hypotonic) Potassium and bicarbonate Mucins (glycoprotein for lubrication ) Amylase Lingual lipase Immune proteins (lysozyme, IgA)
Which gland secrete lipase in the saliva ?
Lingual glands
What is the function of lysozyme in the saliva ?
Destroy microorganism, immune protection
What is the condition of dry mouth called and what consequence can it have ?
Xerostomia
Dysphagia Oral candidiasis (thrush) Ulcers Dental cavities ...
Describe the basic topography of the salivary glands
Parotid glands : lateral Ramus of mandible , duct runs medially to masseter through buccinator
Sublingual glands : Above the floor of mouth , multiple ducts laterally
Submandibular glands : underneath floor of mouth with a superficial lobe going above , one duct open medially under tongue
Which muscle forms the floor of the mouth ?
Mylohyoid
How are the salivary gland controlled ?
Parasympathetic innervation :
Parotid : Glossopharyngeal nerve ( CN IX)
Submandibular and Sublingual : Parasympathetic fibres of the Facial nerve CN V
Which drugs would have dry mouth as a side effect ?
Anti muscarinic drugs
Which disease commonly cause swelling of the parotid glands ? Which other symptoms are seen ?
Mumps
Inflammation of parotid gland, ovaries , testicles, encephalitis
Why is swelling of the parotid gland so painful ?
Covered by fibrous capsule , can’t expand
Which test is used to see stone in parotid duct ?
Sialography
What are the 3 stages of swallowing ?
Oral preparatory phase
Pharyngeal phase
Oesophageal phase
What happens in the first phase of swallowing ? How is the control ?
Bolus pushed towards pharynx by tongue
Voluntary
What happens in the second phase of swallowing ? How is the control ?
- Soft palate seals off nasopharynx
- Pharyngeal constrictors push bolus down
- Larynx elevates, epiglottis close to over airway and vocal cords adduct
- Opening of Upper OS
Involuntary
What happens to the breathing function during swallowing ?
Temporarily ceases
How does the larynx elevates during swallowing ?
Pulled by supra hyoid muscles due to movement of hyoid bone
What happens in phase 3 of swallowing ?
Closure of UOS
Peristalsis move bolus down oesophagus
Why can babies breath and drink at same time ?
Epiglottis projects up in nasopharynx ,in contact with uvula > milk is diverted laterally to oesophagus whilst air goes down pharynx
What development enables speech ?
Neck elongation ,pulling down epiglottis allowing sound formation from the larynx to go to oral cavity
How is swallowing controlled ?
Mechanoreceptors at back of throat detect bolus>Glossopharyngeal nerve CN IX > Medulla > Motor response via Vagus nerve > Pharyngeal constrictors
Why do baby have more pronounced gag reflex?
Adults only Glossopharyngeal stimulation causes gag reflex , in babies , stimulation of more anterior structures do too
How might a stroke affecting the muscles of the face affect swallowing?
Area of brain supplying the facial muscles near the area supplying the pharyngeal constrictors
What can be the symptoms of an oesophageal tumour ?
Feeling off food sticking
Dysphagia
Describe the anatomical location and relations of the oesophagus
Posterior mediastinum
Posterior to trachea and larynx ,at the right of aorta
At which level is the oesophagus going through diaphragm ?
T10
What are the points of oesophageal narrowing ?
- At junction with pharynx
- Where it’s crossed by arch of aorta
- Where it’s compressed by the left main bronchus
- At the oesophageal hiatus in diaphragm
What are the five anatomical mechanisms preventing reflux?
- LOS : functional sphincter formed by thickening off smooth muscle
- Diaphragm
- Intra-abdominal oesophagus part gets compressed when intra abdominal pressure rises
- Mucosal rosette at cardia
- Acute angle of entry in stomach
