L2*-Functions of the mouth and the oesophagus Flashcards
(25 cards)
Define Digestion and where does it start?
The conversion of dietary nutrients into a form that the small intestine can absorb.
Starts at oral cavity(mouth)
What is the function of mouth in digestion?
Break down food physically & chemically, also facilitating its movement to the next stage of digestion.
What is mouth lined by and what does it allow?
The mouth is lined by mucous membranes-oral mucosa.
Allows the secretions to work together in churning up the food.
What are some secretions in the mouth?
saliva, salivary amylase, mucus and lysozyme
What is special about lysozymes in the 👄?
It is antimicrobial.
It’s a antibacterial for any bacteria entering the mouth.
What is the function of uvula? ( tear-drop shaped tissue dangling at the back of the throat)
-Swallowing: It helps prevent food and liquid from going up your nose when you eat or drink.
-Speech: In some languages, like French and Arabic, the uvula helps form certain sounds.
-Saliva production: It secretes saliva to keep your mouth and throat moist.
-Gag reflex: It plays a role in preventing choking by triggering the gag reflex if something goes down the wrong way.
Function of teeth
-Mastication=chewing food
-decrease particle size(👆se the s.a of the ingested food)
-larger s.a in the food allows better action of the digestive enzymes.
Function of tongue
-Taste -The papillae contain taste buds that has gustatory cells(taste receptors)
-Prepares food for swallowing - cohesive bolus.
-motility-how food moves in the👄
Function of saliva and what it contains
-Saliva contains water(99.5%), electrolytes, mucus, amylase, lysozymes.
-major role in motility, taste, cleaning the 👄
Name 2 types of salivary glands and who controls them?
Parotid, Submandibular(produces most of the saliva) , Sublingual glands are innervated by the parasympathetic autonomic nervous system.
Name features of the salivary gland and what it secretes? 2 things?
-Salivary gland is an exocrine gland.
-It contains branched ductal system used to release secretory products-saliva.
-salivary gland gives 2 types of secretions:- serous(protein) and mucous(lubricant).
Name functions of Acinar cells in the salivary gland and what is the state and pH of saliva.
-produces saliva by transporting ions(Na, K, Cl) across cell membranes.
- they also secrete enzymes, proteins and other substances.
***saliva is hypotonic and alkaline.
Why Saliva alkaline?
6.2-7.6 bc amylase is most effective in alkaline conditions, has a buffering capacity.
Name functions of goblet(ductal) cells.
Lubrication =secretion of mucus and other fluids that help maintain a smooth flow of substances through the ducts.
Hydration - keeps the oral mucosa moist and prevents dehydration and cell death.
Cytoprotection - protects oral and oesophageal mucosa from damage.
Name 2 salivary gland diseases
- Sjogren syndrome
- autoimmune condition that affects salivary and tear glands which results in dry mouth and eyes.
- associated with rheumatoid arthritis: commonly affects women. - Mumps virus
-mumps is a viral infection that causes parotitis.
-swelling of the parotid gland(bilateral)
-MMR vaccine is for this.
Describe the oesophagus and a function
-A muscular tube that connect the pharynx to the stomach
-mucus is secreted in both pharynx an oesophagus
-upper 1/3 of the oesophagus contains striated muscle,
👆
middle 1/3 of the oesophagus contains both,
👇
lower 1/3 of the oesophagus contains smooth muscle.
Describe the process of swallowing. Both voluntary and involuntary but which ones?
- Oral Preparatory Phase - food is manipulated in the mouth and masticated to reduce to a consistency (large s.a) which can be
swallowed, in mouth. V - Oral Transport Phase - the tongue propels food posteriorly until the pharyngeal swallow is triggered. V
- Pharyngeal Phase - once the pharyngeal swallow is
triggered, the bolus is transported through the pharynx with coordinated closure of the glottis via movement of the epiglottis and cessation of breathing and relaxation of the upper oesophageal sphincter (UOS). V - Oesophageal Phase(smooth💪) - oesophageal peristalsis carries the bolus from the UOS through the oesophagus to the Lower
oesophageal Sphincter. InV
What structures prevent the food going the trachea ?
-Uvula
-tongue
-epiglottis-leaf shaped cartilage, covers the larynx by folding backwords when eating of drinking
-upper sphincter
what does GORD stand for?
Gastro-oesophageal reflux disease
- a disorder where acid from the stomach leaks into the oesophagus, affecting the lining.
-causes 👉 obesity, hiatus hernia, drugs that lower tone at LOS (anti
cholinergic, beta agonist,
benzodiazepines), pregnancy, Zollinger
Ellison syndrome and gastrin secreting
tumour.
4 effects of GORD
- Oesophagitis
- Stricture
- Barrett’s metaplasia (BM)
- Oesophageal adenocarcinoma (OAC)
Describe the 3rd effect of GORD in more detail
-Metaplasia - change of epithelial type in response to environmental stress.
-10% of patients with GORD develop Barrett’s metaplasia(BM)
-pre-malignant condition for oesophageal adenocarcinoma.
What are the 3 types of treatments for GORD?
- Conservative -
weight loss
avoid food/alcohol close to bed time
👇se alcohol
raise head of bed 20-30cm - Medical
👇se acid -proton pump inhibitors, H2 blockers
antacids 👆se pH
Alginates( Gaviscon) - Surgical
anti reflux surgery ‘fundoplication’
repair hiatus hernia
vagotomy - 👇se acid production
What is Achalasia?
-dramatic reduction in the no.of neuronal cells in the lower oesophageal segment.
-difficult for food to pass from the oesophagus in to the stomach due to impaired oesophageal peristalsis.
- progressive degeneration of myenteric neurons prevents the lower oesophageal sphincter from relaxing. This results in dilation of the oesophagus.
-difficulty swallowing(dysphagia), regurgitation of undigested food, pain.
What does a manometry do?
measures the pressure of the oesophagus
