Case 1 - PBL Flashcards
what is included in the voluntary phase of swallowing
mastication: leads to a bolus of food being produced, during this stage the back of the tongue is elevated and the soft palate pulled anteriorly against it. this keeps the food within the oral cavity and allows the airway to remain open
what happens after mastication in the voluntary phase
inspiration is inhibited and the bolus of food is moved to the pharynx by the tongue. this leads to the stimulation of the swallowing reflex
what is the nerve involved in the voluntary phase
the trigeminal nerve
what happens in the pharyngeal phase
Once the bolus has been moved to the pharynx, pressure receptors are activated in the palate and the anterior pharynx. This signals the swallowing centre in the brain stem which:
inhibits respiration
Raises the larynx
Closes the glottis
Opens the upper oesophageal sphincter
Levator and tensor veli palatini
what else happens to prevent aspiration
the true vocal cords are closed
what happens after the vocal cords are closed and the soft palate is elevated
the bolus is moved towards the oesophagus via peristalsis of the pharyngeal constrictor muscles. Gravity makes very little contribution to this process and the main factors affecting the speed of this are the viscosity and volume of the bolus.
what is the upper third of the oesophagus
voluntary skeletal muscle
what are the lower two thirds of the oesophagus
involuntary smooth muscle
what muscle prevents reflux
the larynx lowers, returning to its normal position. the cricopharyngeus muscle then contracts to prevent reflux and respiration begins again
what happens after this
The bolus is moved down the oesophagus via peristalsis, which is coordinated by extrinsic nerves. Each area of muscle systematically relaxes to allow food through and contracts afterwards to propel it further. The bolus is propelled at a rate of around 3-5cm per second and so the transit time to the stomach takes around 9 seconds.
digram showing swallowing
what are long periods of low flow of saliva broken by
short periods of high flow, which is stimulated by taste and mastication
what is the nerve mediated salivary reflex modulated by
nerve signals from other centres in the central nervous system, which is most obvious as hyposalivation at times of anxiety
what does circadian rhythm affect
salivary flow and ionic composition
what evokes salivary secretion
Cholinergic parasympathetic and adrenergic sympathetic autonomic nerves evoke salivary secretion, signalling through muscarinic M3 and adrenoceptors on salivary acinar cells and leading to secretion of fluid and salivary proteins.
what do the main proteins present in saliva do
create viscoelasticity and enabling the coating of oral surfaces with saliva
examples of potential disease biomarkers found in saliva
For example, cortisol levels are used in the assessment of stress, matrix metalloproteinases-8 and -9 appear to be promising markers of caries and periodontal disease, and a panel of mRNA and proteins has been proposed as a marker of oral squamous cell carcinoma. Understanding the mechanisms by which components enter saliva is an important aspect of validating their use as biomarkers of health and disease.
what are the parasympathetic nuclei that control salivary glands in the brainstem
the superior and inferior salivatory nucleu
parasympathetic stimulation
an increase in the secretion of watery saliva, is mediation by CN7&9 from the superior and inferior salivatory nuclei in the brains stem via muscarinic receptors
Parasympathetic nerve stimulation occurs via the IP3 intracellular pathway, whereby calcium released in this pathway activates the relevant channels and transport proteins to cause this increase in secretion
sympathetic stimulation
mediated by Beta-adrenergic receptors and causes an increase in secretion of viscous saliva
Sympathetic stimulation increases salivation a slight amount, much less so than parasympathetic stimulation
salivation also occurs in response to reflexes originating in the stomach and upper small intestines - particularly when irritating foods are swallowed
The saliva when swallowed, helps to remove the irritating factor in the gastrointestinal tract by dilating or neutralising the irritant substance.
why does blood supply affect saliva production
because secretion always requires adequate nutrients from the blood
does salivation dilate blood vessels
yes, thus providing increased salivary gland nutrition as needed by the secreting cells
what is part of this additional vasodilator effect caused by
kallikrein secreted by the activated salivary cells, which in turn acts as an enzyme to split one of the blood proteins to form bradykinin, a strong vasodilator
what is the serum ferritin test and what are normal results
measures the amount of ferritin in your blood
Is a blood protein that contains iron
A ferritin test helps your doctor understand how much iron your body stores
Ferritin stores iron
Normal results:
Woman: 11-307 micrograms per litre
Men: 24-336 micrograms per litre
what is ESR and what are the normal results
blood test that can reveal inflammatory activity in your body
When your blood is placed in a tall, thin tube, red blood cells gradually settle to the bottom.
Inflammation can cause the cells to climb
Because these clumps are denser than individual cells, they settle at the bottom more quickly.
The sed rate measures the distance red blood cells fall in a test tube in one hour
The farther the red blood cells have descended, the greater the inflammatory response of your immune system.
The normal values are: 0 to 15 mm/hr in men. 0 to 20 mm/hr in women.
what is the upper GI criteria for a HSC205 referral
people with dysphagia, or those aged 55 years and over with weight loss and any of the following:
- upper abdominal pain
- reflux
- dyspepsia
PEG tube benefits and facts
avoids mouth/nose issues
More invasive
Requires endoscopy
Better tolerated
displacement less likely
Endoscopic procedure
Percutaneous wound
Larger bore tube
long term
Continuous/bolud
Fluid
More expensive
Can aspirate
Avoids interfering with gastro-oesophageal sphincter
NG tube positives and facts
simple
Commonly used
No need for anaesthesia
trauma
Misplacement
Requires X-ray
Easily dislodged
Sinusitis
short term
Continuous/bolus
Fluid
cheap
Can aspirate
Buffers gastric acids
Bactericidal action of acid
Pepsin and lipase help with absorption
what is oesophageal stenting
a tube is placed in your oesophagus to keep open a blocked area
The tube helps you swallow solids and liquids
Used when you have dysphagia
Can take place under general anaesthesia or conscious sedation
If it takes place under GA you will sleep through the procedure and feel no pain
If it takes place under conscious sedation, you will get medications to make you relaxed and sleepy
mechanism of action of omeprazole
is a proton pump inhibitor
It is a substituted benzimidazole that belongs to the antisecretory class of compounds
It inhibits the parietal cells H+/K+ ATP pump, the final step of acid production
In turn, omeprazole surpasses gastric basal and stimulates acid secretion
The inhibitory effects occur rapidly, within 1 hour of administration.
Lasts 72 hours after administration
extensively metabolised by the hepatic cytochrome P450 enzyme system
self regulation model of illness cognition
unidimensional measures of QoL
these measures assess health in terms of one specific aspect of health
They can be used on their own or in conjunction with other measures
Examples:
General heath questionnaire - assesses mood
McGill Pain Questionnaire - assesses pain levels
Self esteem scale
Measures of social support
Measures of satisfaction with life
Measures of symptoms
multidimensional measures of quality of life
these measures assess health in the broadest sense
Aren’t always long and complicated
Doctors can simply ask respondents to make a relative judgement about their health on a scale from best to worst possible
individual measures of quality of life
measures of subjective health status ask the individual to rate their own health
This is in contract to measures of mortality, morbidity and most measures of functioning which are completely by carers, researchers or an observer
Although these measures enable individuals to rate their own health, they do not allow them to select the dimensions along which to rate it.
For example, a measure that asks about an individual’s work life assumes that work is important to this person, but they might not want to work
what is pneumonitis
inflammation of the lung tissue
