Oral Cavity and Oesophagus Flashcards
what are the 4 main functions of the GI tract
motility
secretion
digestion
absorption
what allows the slow wave activity to be passed through the entire GI tract
gap junctions
each slow wave triggers a contraction true/false
false - slow wave must reach a certain threshold to initiate a contraction and this is dependent on neuronal and hormonal stimuli
what are the two types of muscle throughout the GI tract
circular and longitudinal
during smooth muscle contraction, circular muscle becomes
longer and narrower
during smooth muscle contraction, longitudinal muscle becomes
shorter and fatter
what drives the slow wave contraction and where are they located
interstitial cells of Cajal - pacemaker cells
located between the circular and longitudinal muscle layers
what is the effect of the parasympathetic NS on GI tract
increases gastric secretions, motility and blood flow
relaxes stomach and sphincters
what nerves supply the parasympathetic NS in GI tract
vagus nerve supplies until the descending colon then spinal nerves 2, 3, 4 supply distal part of the tract
what is the effect of the sympathetic NS on GI tract
decreases motility, secretions and blood flow
increases sphincter tone
what is the function of the enteric nervous system
governs the function of the GI tract
myenteric plexus - sphincters and motility
submucous plexus - epithelia and blood vessels
define peristalsis
wave of relaxation followed by contraction to move a food bolus along the tract. triggered by gut distension
describe segmentation
rhythmic contraction of circular muscle layers which work to mix and churn the chyme dividing luminal contents
what are the spincters of the GI tract and their function
upper oesophageal sphincter - swallowing
lower oesophageal sphincter - travels food to stomach
pyloric sphincter - for gastric emptying regulation
ileo-caecal - regulates flow
internal and external anal sphincter for defaecation
how many teeth does an adult have
32
where is saliva first formed and then where is it modified
formed in the acinar cells
modified by duct cells
name the 3 salivary glands
parotid
submandibular
sublingual
where does the parotid gland secrete saliva into and which nerve innervates it
secretes saliva into the mouth via upper second molar
innervated by glossopharyngeal nerve
where does the submandibular gland secrete saliva into and how much
secreted into the floor of the mouth - 70% of total saliva
what nerve supplies the submandibular and sublingual glands
facial nerve
at what point does the laryngopharynx become the oesophagus
C6
where does the oesophagus terminate at the cardia of the stomach
T10
the upper oesophageal sphincter is physiological only true/false
false UOS is anatomical
lower is physiological
what are the 4 physiological restrictions at the oesophagus
A - arch of the aorta
B - bronchus (left main stem)
C- cricoid cartilage
D - diaphragmatic hiatus
what are papillae and what is within them
bumps on the tongue - taste buds are located within them.
name the 3 types of papillae that contain taste buds
vallate, fungiform, fusiform
filiform doesnt contain taste buds
what are the main causes of acute oesophagitis
ingestion of chemicals
infection in immunocompromised patients (candidiasis, herpes, CMV)
what are the symptoms associated with oesophagitis
dysphagia
odynophagia
chest pain
what treatment is used for acute oesophagitis
antibiotics/antivirals if required
corticosteroid to reduce inflammation
what is the main causes of chronic oesophagitis
reflux disease (GORD)
what are the causes of GORD
increased intra-abdominal pressure eg obesity, pregnancy
gastric acid hypersection
LOS dysfunction
what are the symptoms of GORD
dysphagia odynophagia heart burn water brash chest pain - after eating/at night
what is the treatment for GORD
PPIs eg omeprazole
antacid tablets
lifestyle advice to reduce incidence
what are 3 complications of chronic oesophagitis
ulceration/bleeding
stricture
Barretts Oesophagus
define Barretts Oesophagus
replacement of stratified squamous epithelium with simple columnar epithelium reduce to persistent abuse from acid and bile
why can Barretts Oesophagus be described as pre-malignant tissue
form of metaplasia because mature cells are differentiating and growing abnormally
what is allergic oesophagitis
chronic type of oesophagitis
who typically develops allergic oesophagitis
those with personal/family history of asthma and other allergies
males > females
what investigations are done for those with allergic oesophagitis
blood tests for eosinophilia
pH probs to exclude acid reflux
what is the treatment for allergic oesophagitis
corticosteroids such as prednisolone - can be used alongside monkelukast
benign oesophageal tumours are more common than malignant tumours true/false
false - malignant more common
what is the most common type of benign oesophageal tumour and what is it associated with
squamous cell papilloma
associated with HPV 16 and 18 - usually asymptomatic
what are the two types of malignant tumours that can develop in the oesophagus
adenocarcinoma
squamous cell carcinoma
what is the aetiology of oesophageal malignancies
caucasian smoking males obesity genetics
Barretts Oesophagus increases likelihood of which cancer? where in the oesophagus is it most likely to develop
adenocarcinoma
lower 1/3 of oesophagus because thats where is most likely to develop Barretts from GORD
what are the symptoms of oesophageal cancer
progressively worsening dysphagia odynophagia haematemesis weight loss anaemia stricture lymphadenopathy
what is the best treatment for oesophageal cancer
surgical resection - dependent on co-morbidities with neo-adjuvant chemotherapy
if localised treat with radical chemo
