Anatomy of Swallowing Flashcards
Give 4 functions of saliva.
- Lubrication (and formation of a bolus)
- Antibacterial properties
- Beginning of digestion
- Protects teeth
Give 2 antimicrobial agents found within saliva.
- Lactoferrin
- Lysozyme
- IgA
Name 2 digestive enzyme present in saliva.
- Amylase
- Lingual lipase
Name the 3 salivary glands and their innervations.
- Parotid (Glossopharyngeal Nerve Cn. IX)
- Sublingual (Facial nerve Cn. XII)
- Submandibular (Facial nerve Cn. XII)
What number cranial nerve is the vagus nerve also known as?
Cn. X
Saliva is rich in which electrolights?
- K+
- HCO3- (carbonate)
Name a cause of parotitis.
- HIV
- Mumps
- Staph aureus infection
- Complication of extra pulmonary TB
Xerostomia is the medical term for what condition?
Dry mouth
Name 2 causes of xerostomia.
- Hang over (dehydration)
- Anti-muscarinic drugs
- Anti-depressants
Give a complication of xerostomia.
- Difficulty swallowing
- Infections
- Dental problems
Name and briefly describe the 3 phases of swallowing.
- Oral: The food is mechanically and enzymatically digested and compacted together to form a bolus. It is then moved to the back of the mouth by the tongue where it is forced into the pharynx as the nasopharynx is blocked by the soft pallet.
- Pharynx: The larynx is blocked by the epiglottis and the adduction of the vocal chords so the bolus is forced down the pharynx.
- Esophagus: The upper esophageal sphincter is opened allowing the bolus to automatically move through.
Breathing and swallowing isn’t simultaneously possible. There is one species that are an exception to this, name it and explain why it is possible.
Babies can do both simultaneously. This is because their epiglottis doesn’t fully seal off the larynx, rather it lies more horizontally, therefore babies can still breath whilst feeding.
Describe the neural control of swallowing (both afferent and efferent).
Mechanoreceptors at the back of the throat are stimulated by a bolus. This is detected by the glossopharyngeal nerve which relays this sensory innervation to the medulla thus forming the afferent response.
The efferent response is provided by the medulla via Cn. X which provides the motor function via the pharyngeal constrictors.
The esophagus is connected to 2 different structures. Give there names.
- Laringopharynx
- Stomach
Which of the 2 esophageal sphincters is muscular?
Upper
The constriction of the lower esophageal sphincter is formed by 2 factors. Name these.
- The acute angle at which it enters the stomach
2. The diaphram
The esophagus passes the diaphragm at which thoracic vertebral level?
T10
The lower esophageal sphincter is notoriously poor. Explain why this is of medical consideration.
Concerns around acid reflux as this over time causes a change in epithelium from stratified squamous to simple columnar. This displastic change causes an increase chance for mutations and therefore eventually esophageal cancers.
What is Barret’s esophagus.
Barrett’s esophagus is a serious complication of gastroesophageal reflux disease. In Barrett’s esophagus, normal tissue lining the esophagus – the tube that carries food from the mouth to the stomach – changes to tissue that resembles the lining of the intestine.
What is acid reflux also commonly referred to as?
Heart burn
Give 2 differential diagnosis for upper abdominal pain.
- MI
- Acid reflux
- Angina
- Pneumothorax
- Costolitis
- Cardiac tamponade
How could a brain injury lead to difficulty in swallowing?
Anything affecting Cn.IX or Cn.X will affect the sensory and motor respectively of the oropharynx hence affecting the ability to swallow.
Give a respiratory complication of difficulty swallowing.
Aspiration pneumonia
