Exam Qs Flashcards
3 main routes of metastatic cancer spread
lymphatic
haematogenous
transcoelomic
eg of cancer spreading and where it metastasises to
colon cancer can metastasise to liver-colon
name 2 classifications of cancer and their subgroups
clinical: benign or malignant
histological: epithelial or mesenchyme
5 features of a benign tumour
- growth is slow
- growth in non-invasive
- benign tumours do not spread
- tumour margins are not well defined
- they do not recur when removed
5 features of a malignant tumour
- growth is rapid
- growth is invasive & destroys tissue
- tumour spreads
- recurrence after excision is very common
- tumour margins are well defined
name 2 benign tumours and their tissue of origin
1.lipoma - fat tissue
2. chondroma - cartilage
name 2 malignant tumours and their tissue of origin
- carcinoma - epithelial cells
- lymphoma - blood forming cell
what are demographic factors and name some
characteristics of a population expressed statistically e.g. gender, age, postcode, employment status, religion, birth rate, death rate
name 5 types of questionnaires
- open
- closed
- scales (likert scales)
- yes / no
- rhetoric
what are the 5 stages of feeding
- ingestion
- stage 1 transport
- mechanical processing
- stage 2 transport
- swallowing pharyngeal phase
describe ingestion
movement of food from external to internal environment
describe stage 1 transport
food gathered on tongue tip and moved to level of posterior teeth
describe mechanical processing
solid foods are broken down and mixed with saliva before swallowing
moist solid foods e.g. fruit has to have fluid removed before transport and swallowing
food is chewed with premolars & molars and soft foods are squashed against hard palate
describe stage 2 transport
bolus moved posteriorly by ‘squeeze back’
solid foods moved through fauces to pharyngeal surface of tongue
‘seal’ holds liquids at pillars of fauces
describe the swallowing pharyngeal phase
involuntary movements push bolus through pharynx into oesophagus
epiglottis seals off larynx preventing food entering the respiratory tract
UOS relaxes to allow bolus into oesophagus and then contracts to counteract backflow
why does ditching occur in amalgam restorations
material is repeatedly stressed for long periods of time at low level stresses below the elastic limit
it may flow resulting in permanent deformation
amalgam sits proud of surface due to flow and is vulnerable to fracture
what can we do in cavity prep to prevent amalgam ditching
remove all caries
correct acid etch & bond
use a lining material
lining material will help spread force down long axis of the tooth, instead of placing stress on interface between tooth & restoration
this will reduce stress on amalgam therefore reducing creep and therefore ditching
4 factors contributing to formation of secondary caries underneath an amalgam restoration
- microleakage due to no chemical bond between restoration & tooth
- fracture of enamel at margins causing ditching compromised any seal that was present at restoration / tooth interface
- poor oral hygiene will prevent removal of cariogenic plaque and allow proliferations around margins
- if no lining material underneath amalgam the dentine has no protection from bacteria & endotoxins
5 risk factors for a high caries incidence
- poor OH regime over time (brushing & flossing)
- susceptible tooth surface i.e. tight contacts, receded gingiva
- diet - high in sugars/fermentable carbohydrates forming cariogenic plaque & frequency of intake
- presence of cariogenic bacteria - strep mutans / lactobacilli
- xerostomia - drugs, disease, diet
how is cystic fibrosis passed down
inherited disorders
explain the genetics of cystic fibrosis
CFTR gene - chromosome 7
recessive gene so both parents must have the gene
how to treat cystic fibrosis
physio
medication
exercise
transplantation
how does cystic fibrosis affect the body (4)
- inherited defect in cell Cl- channels
- produces excess sticky mucus
- lungs are congested
- pancreas: malabsorption of nutrients
how to test for cystic fibrosis
- perinatal testing; all children now screened at birth
- sweat test; measures salt content of sweat which is higher in CF patients
eg adv & disadv of IV medication
e.g. - midazolam
adv - rapid, immediate onset of drug, avoids FPM so nearly 100% bioavailability, continuous, closely monitored administration
disadv - required IV access which is painful & can be difficult to obtain, increased infection risk
eg, adv & disadv of subcutaneous medication
e.g. - insulin, heparin
adv - avoids FPM so higher bioavailability in body, constant, slow & prolonged absorption by fatty tissue
disadv - needle breaks protective barrier against infection
eg adv & disadv of IM medication
e.g. - glucagon, adrenaline
adv - rapid onset, shorter duration, muscle can absorb liquid better than subcutaneous layer
disadv - neurovascular (nerve) damage, bleeding, painful & infection risk, dependent on blood flow: delayed absorption in shock
eg adv & disadv of transdermal medication
e.g. - isosorbide mononitrate
adv - avoids FPM so higher bioavailability in body, controlled & continuous release
disadv - skin is an effective barrier; only small molecule medications can work
why do we need a hybrid layer to bond to
carious dentine has a lower hardness and presence of mineral deposits in the tubules
this makes it difficult to produce the hybrid layer as there are denatured collagen fibres
without a sufficient hybrid layer in place, bond strength will be significantly weaker
how do we overcome the hybrid layer problem
RMGI - remineralisation through F- release
using self -etch technique to penetrate and incorporate smear layer
how to label micrograph of hybrid layer
hybrid layer can be seen overlying dentine
resin tags - resin that has permeated down tubules for micromechanical retention
outline creation of a hybrid layer
- hybrid layer consists of collagen network exposed by etching & embedding adhesive resin (resin tags) it is the interface between dentine & adhesive resin
- smear layer is first removed using a 37% phosphoric acid conditioner - top 10microM
- hydrophilic monomer (HEMA) penetrates the hydrophobic dentine surface (preferably primary, well structured dentine) and embeds the collagen fibres forming the hybrid layer
reasons why a bond to dentine might fail (4)
- over etch - collagen fibres collapse therefore the resin cannot penetrate
- over etch - too deep an etch and the primer cannot penetrate the full depth of the etch
- too dry - dentine surface collapses
- too wet - primer is diluted and strength is reduced
what the 3 stages in forming a clot
- vasoconstriction
- platelet plug & aggregation
- conversion of fibrinogen to fibrin by thrombin
how does aspirin affect clotting
prevents formation of a platelet plug - inhibits platelets aggregation by altering balance between thromboxane A2 & prostacyclin
how does warfarin affect clotting
impacts conversion of fibrinogen to fibrin as it inhibits vitamin K dependent reactions of the coagulation cascade
how does heparin affect clotting
affects conversion of fibrinogen to fibrin as it is an indirect thrombin inhibitor. it binds antithrombin III & enhances natural anticoagulatory effect
aspirin & clopidogrel are often used in conjunction - why and what is their function
together they are effective anticoagulants; reducing risk of blood clotting so reducing risk of heart attack or stroke in the at risk population.
aspirin - inhibits platelet aggregation by altering prostacyclin / thromboxane A2 balance
clopidogrel - inhibits ADP induced platelet aggregation
explain genetics behind von willebrand’s disease
autosomal dominant inheritance so one parent has the recessive gene
how does von willebrand’s disease affect haemorrhage
reduced factor XIII level
vWF binds to this to prevent rapid breakdown in blood
reduced platelet aggregation as a result of deficient factor XIII
example of an antiplatelet and how it works
aspirin - enhances bleeding by inhibition of platelet aggregation altering balance between thromboxane A2 & prostacyclin; irreversible for the life of the platelet (7-10 days)
example of an anti-coagulant and how it works
warfarin - inhibits vitamin K dependent reactions of coagulation cascade
what constitutes hypertension
> 140/90mmHg
120/80mmHg is considered normal
what is bioavailability
fraction of an administered dose of unchanged drug that reaches systemic circulation and is available for clinical effect
what is first pass metabolism
concentration of drug is greatly reduced before it reaches the systemic circulation
fraction of a drug lost during process of absorption in the gut and metabolism in the liver
2 disadvantages of oral route of medication
- FPM effect reduces amount of drug passed to systemic circulation
- risk of drug causing gastric irritation & ulceration e.g. NSAIDs
describe flowable composite (5)
lower filler content so less viscous than conventional composite
used for filling pit / fissure system, small fractures & as a luting agent
higher polymerisation shrinkage
lower fracture strength
place with fibre ribbons
describe wettability of flowable composite
adhesion requires an intimate contact between the adhesive material and substrate
to obtain maximum contact area between liquid adhesive and solid surface the substrate must show evidence of high wettability with regard to that liquid (hydrophilicity or dentine & material)
using acid etch technique
opportunity for excellent bond between composite & enamel
describe the light curing of flowable composite
extended working time
less finishing / waste / porosity
reasons against using flowable composite (4)
- reduced mechanical properties
- lower availability of shades
- more difficult to sculpt due to decreased viscosity
- discolouration over time
will use of 1 6mm increment of flowable suffice
no - takes 20 seconds to cure 2mm
larger than 2mm increments will result in an under polymerised base
describe polymerisation shrinkage
dependent on filler particle volume
affects bond to tooth - stresses develop at hard tissue (high configuration factor is a problem)
potential for cuspal fracture & microleakage
hinders good marginal adaptation
what are the 10 SICPs
- patient placement / assessment for infection risk
- hand hygiene
- respiratory & cough hygiene
- PPE
- safe management of care environment
- safe management of care equipment
- safe management of linen
- safe management of blood and body fluid spillages
- safe disposal of waste (inc sharps)
- occupational safety: prevention of exposure (inc sharps injuries)