Revision Flashcards
Xray photons are generated in the tube head
Contains two electrodes
Negatively charged cathode
Positively charged anode
Electrons are produced at cathode (a coiled wire filament)
Tungsten is used as filament as has a high atomic number (74) and high melting point (3380oc)
The filament sits in a nickel or molybdenum focusing Cup at a negative potential so repels the elections causing to form a narrow beam.
Multiplying the ma by duration reflects the total quantity of xray photons emitted in millampre secs.
The potential difference between filament and target needs to be very high and many times voltage of mains supply of 240 volts.
It’s measured in 1000s of volts or kv. And created from mains in a second electrical circuit using step up or high tension transformer - also part of the electrical circuitry of x Ray machine.
A common preservative in fixer is
Sodium sulphite
A dog inspires once every respiratory cycle and breathes 100mls in and out. What is the mv?
2L
A film that is too dark may be the result of
Over exposure Gross over development Temp of developer too high Fogging Ffd too short
An example of a natural absorbable suture material is
Catgut
Anticholinergics often used in premed
To decrease salivary and bronchial secretions
Apposing sutures are those that are placed
With the wound edges in direct contact with one another
A suture property that is not ideal
High capillarity
A rad requires exposure of 20mAs when ffd at 90 cm with a grid. What exposure factor will be required if a grid with a factor of 2 is used?
40mAs
A simple continuous suture pattern should not be used in
Hollow organs
Assuming all other factors stay same, rads obtained with setting of 0.05sec and 200mAs are identical to
0.1 sec and 100mA
So if ma is halved then double seconds
When anaesthetised first reflex to go is
Anal
A trolley should be draped
Back to front
Flow rate of oxygen and nitrous oxide for 30kg on magill lack with mv of 200ml/kg
30 x 200 x1
Divide by three then x by 2 to get nitrous
Computer aided tomography is carried out using
X rays
Tissue sample containers
Wide necked
Diastolic BP should not drop below
150mm/hg
Drains are indicated in
Abolishing dead space in wounds
Drainage of contaminated wounds
Removal of air from body cavities
Hydrophyllic drugs are more easily absorbed
Iv or im
Lipophyllic drugs are more easily absorbed
Po or sc
If increase film to object distance the image is
Magnified
