Cells and Molecules

Question 1

Where does NH+ of LA bind

Answer 1

Voltage gated sodium channels - active gate

Question 2

Types of bacteria (4)

Answer 2

1. Gram positive
2. Gram negative
3. Cocci
4. Bacilli

Question 3

Round bacteria

Answer 3

Cocci

Question 4

Pinkish purple bacteria

Answer 4

Gram positive

Question 5

Growth Conditions for bacteria (4)

Answer 5

1. Aerobic
2. Capnophilic
3. Facultative
4. Strictly Anaerobic

Question 6

Aerobic Bacteria

Answer 6

Oxygen

Question 7

Capnophilic bacteria

Answer 7

Carbon dioxide

Question 8

Facultative bacteria

Answer 8

With and without bacteria

Question 9

Strictly anaerobic bacteria

Answer 9

Without oxygen

Question 10

Types of antibiotic resistance (2)

Answer 10

Intrinsic
Acquired

Question 11

Types of acquired antibiotic resistance (2)

Answer 11

Mutation
Acquisition of new DNA

Question 12

Ways bacteria can acquire new DNA (3)

Answer 12

1. Transformation
2. Transduction
3. Conjugation

Question 13

Mechanisms of antibiotic resistance (3)

Answer 13

Altered target site
Enzymatic inactivation
Decreased uptake

Question 14

ESBL

Answer 14

Extended spectrum beta-lactamases

Question 15

CPE

Answer 15

Carbapenemase Producing Entraales

Question 16

Charge of ICF (2)

Answer 16

-ve compared to ECF
Although equal number of +ve and -ve charges in ICF and ECF but charge distribution is polarised

Question 17

Where are there more sodium ions (neurone)

Answer 17

ECF

Question 18

Where are there more potassium ions (neurone)

Answer 18

ICF

Question 19

Where are there more chloride ions (neurone)

Answer 19

ECF

Question 20

What ion is the resting membrane permeable to

Answer 20

Potassium
The diffusion of potassium is what is responsible for the RMP

Question 21

RMP

Answer 21

Resting membrane potential

Question 22

How does the Na/K Pump contribute to RMP? (2)

Answer 22

Exchanging unequal numbers of Na and K
Expelling any Na that leaks into cell

Question 23

Threshold for action potential

Answer 23

-55mV

Question 24

Cause of rising phase of AP

Answer 24

Na influx
Voltage gated Na channels

Question 25

Cause of falling phase of AP

Answer 25

K efflux Voltage gated K channels

Question 26

AP - What happens before MP reaches the threshold

Answer 26

Depolarisation

Question 27

AP - MP peak

Answer 27

35mV

Question 28

Refractory period (2)

Answer 28

Period of inexcitability after AP Due to inactivation of voltage gated sodium channels

Question 29

Can AP add together

Answer 29

No They are all or none events

Question 30

Consequences of the refractory period (2)

Answer 30

Limits maximum firing potential Ensures unidirectional propagation of AP

Question 31

How does AP travel along the axon (2)

Answer 31

AP in one section depolarises the next section of 'resting' axon This continues as a wave of depolarisation

Question 32

AP propagation and size of axon

Answer 32

Speed of propagation increases with axon diameter

Question 33

What cells lay down myelin

Answer 33

Glial cells

Question 34

Interruption of myelin sheath

Answer 34

Nodes of Ranvier

Question 35

Nodes of Ranvier purpose

Answer 35

Axon membrane is exposed to ECF and ion flow can occur

Question 36

Saltatory conduction

Answer 36

In myelinated nerves, fewer regeneration steps per unit length of axon

Question 37

What type of axons are unmyelinated

Answer 37

C

Question 38

Examples of bacteria involved in dental abscesses (2)

Answer 38

Streptococcus anginosus Prevotella intermedia

Question 39

Bacteria involved in osteomyelitis of jaws (4)

Answer 39

1. Anaerobic gram negative rods 2. Anaerobic streptococci 3. Streptococcus anginosus 4. Staphylococcus aureus

Question 40

Bacteria involved in Ludwig's angina and SOI (3)

Answer 40

1. Anaerobic gram negative bacilli 2. Streptococcus anginosus 3. Anaerobic streptococci

Question 41

Antimicrobial resistance - S

Answer 41

Susceptible at standard dose

Question 42

Antimicrobial resistance - I

Answer 42

Susceptible at increased dose

Question 43

Antimicrobial resistance - R

Answer 43

Resistance even with increased dose

Question 44

Clinical antimicrobial resistance

Answer 44

When infection is unlikely to respond even to maximum doses of antibiotic (EUCAST)

Question 45

Antimicrobial Stewardship Definition

Answer 45

An organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness

Question 46

Global Plan for Antimicrobial Resistance (5)

Answer 46

1. Improve awareness and understanding 2. Strengthen the knowledge through surveillance and research 3. Reduce the incidence of infection 4. Optimise use of antimicrobial medicines 5. Ensure sustainable investment

Question 47

Why is fluoroapetitie preferable to hydroxyapatite

Answer 47

It is less susceptible to demineralisation

Question 48

When is fluoride most effective

Answer 48

Early lesions

Question 49

How does fluoride effect bacteria

Answer 49

Influences their metabolic pathways which results in less acid being produced

Question 50

Does fluoride work better systemically or topically

Answer 50

Topically

Question 51

What causes discolouration?

Answer 51

The formation of chromogenic products within the tooth structure

Question 52

How does bleaching work

Answer 52

Oxidisation of long chain chromogenic molecules Leads to smaller non pigmented molecules

Question 53

Mechanism of action of CHXD (2)

Answer 53

Bactericidal - opens up cell membranes Bacteriostatic - inhibits bacterial growth

Question 54

Which family does CHXD belong to

Answer 54

Antiseptic

Question 55

Substantivity of CHXD

Answer 55

Residual activity enhances bactericidal effect