Principles of Disease Overview Flashcards
(393 cards)
1
Q
What micro-organisms cause disease?
A
Bacteria Viruses Fungi Parasites Prions
2
Q
For UTI’s what specimen is collected for culture?
A
Mid-stream urine sample
3
Q
In chest infections what specimen is collected for culture?
A
Sputum
4
Q
In Tonsillitis what specimen is collected for culture?
A
Throat swab
5
Q
In diarrhoea what specimen is collected for culture?
A
Stool Sample
6
Q
In bacteraemia what specimen is collected for culture?
A
Blood culture
7
Q
In meningitis what specimen is collected for culture?
A
CSF sample
8
Q
What does microscopy allow?
A
The staining and quick detection of bacteria
9
Q
Can microscopy determine identify the type of bacteria?
A
No
10
Q
What do cultures allow?
A
Bacteria to be grown and identified by looking at their visible appearances and their growth pattern
11
Q
What is a sterile site?
A
A site that should not contain any micro-organisms
12
Q
Give examples of sterile sites
A
Blood
CSF
Bladder
Lungs
13
Q
What is a non-sterile site?
A
A site that can contain commensal microbes that may not harm the body but will show up in microscopy or culture
14
Q
Give examples of non-sterile sites
A
Urethra
Gut
Skin
15
Q
What type of microscopy detects viruses?
A
Electron Microscopy
16
Q
What colour do gram negative bacteria appear?
A
Red
17
Q
What colour do gram positive bacteria appear?
A
Purple
18
Q
What shape are cocci bacteria?
A
Spherical
19
Q
What shape are bacilli bacteria?
A
Rod shaped
20
Q
What is the function of the flagellum?
A
Motility
21
Q
What is the function of fimbriae?
A
Adherence
22
Q
What is the lipopolysaccharide a component of?
A
The cell wall
23
Q
What do PBP’s synthesise?
A
Peptidoglycans
24
Q
What is the name of a bacteria based on?
A
The genus and species
25
Do strains of a species have similar or different characteristics?
Similar
26
What technique is used to identify strains of bacteria?
Typing
27
What are viruses classified according to?
Host range
Virion Structure and morphology
Structure and replication of virus genome nucleic acid
28
Why must cell cultures for viruses take place in cell lines, tissues or animals?
Because viruses require living cells to live
29
What percentage CO2 are viruses grown within?
2%
30
Give examples of viruses that can cause tumour?
HPV
Retrovirus
Hepatitis B
31
Give examples of viruses that can affect the respiratory tract?
Influenza
| Rhinovirus
32
Give examples of viruses that can affect the GI tract?
Rota virus
33
Give example of viruses that can affect the neurological system/
Enterovirus
| Herpes simplex virus
34
What brings about active immunity?
Brought about by a foreign antigen triggering an immune response
35
Does active immunity create immunological memory?
Yes
36
What is an attenuated vaccine?
One where the live organism is used
37
Give examples of attenuated vaccines?
MMR, BCG
38
What are inactivated vaccines?
One where the killed micro-organism is used
39
What is an acellular vaccine?
One where only the antigenic part of the vaccine is used
40
What is a toxoid vaccine?
One where a bacterial toxin is used
41
What is used to inactive the bacterial toxins in toxoid vaccines?
Formalin
42
What is a conjugate vaccine?
Links the antigens or toxoids of the microbe so that it can recognise the polysaccharide layer of certain bacteria
43
Wha does passive immunity involve?
Inoculating the patient with antibodies specific to the pathogen
44
Does passive immunity provide immunological memory?
No
45
What is human normal immunoglobulin?
Contains all antibodies from an unselected pool of random blood donors
46
What is human specific immunoglobulin?
Blood donors selected have a high antibody level against the target organism
47
What is an advantage of passive immunity?
It gives immediate protection
48
What are the 2 broad classes of gram positive cocci?
Streptococci
| Staphylococci
49
What appearance do staphylococci have?
Clusters
50
What appearance do streptococci have?
Chains
51
What test is used on gram positive staphylococci?
Coagulase test
52
What bacteria is staphylococci coagulase positive?
Staph. aureus
53
What bacteria is staphylococci coagulase negative?
Staph. epidermis
54
What are the 3 classes of streptococci?
Alpha haemolytic
Beta haemolytic
Non-haemolytic
55
What bacteria are usually non-haemolytic?
Enterococci
56
What are the 3 classes of streptococci beta haemolytic?
Group A B and C
57
What are the 3 gram positive anaerobic bacilli?
Clostridium difficile
Clostridium Perfinges
Clostridium Tatani
58
Where are exotoxins released?
Extracellularly by the micro-organism
59
What are enterotoxins?
Exotoxins which act on the GI tract
60
What are endotoxins structurally part of?
The gram negative cell wall
61
What are the 3 virus pathogenic mechanisms?
Cell destruction following virus infection
Virus-induced changes to cellular gene expression
Immunopathogenic disease
62
Give an example of cell destruction following viral infection?
T4+ cells death by HIV
63
Give an example of virus0induced changes to cellular gene expression
Cellular transformation by tumour viruses
64
Give an example of an immunopathogenic disease?
Influenza A
65
What is MIC?
The minimal inhibitory concentration - min conc. of antimicrobial needed to inhibit visible growth of a given organism
66
What is MBC?
The minimal bactericidal concentration - min conc. needed to kill the given organism
67
What is sensitive?
When the organism is killed or inhibited by given levels of the antimicrobial
68
What is resistant?
When the given organism is not killed or inhibited by the levels of antimicrobial
69
What is a bactericidal?
An antimicrobial that kills bacteria
70
What is a bacteriostatic?
An antimicrobial that inhibits the growth of a bacteria
71
What are the three mechanism that antibiotic use to combat bacteria?
Inhibit the synthesis of the cell wall
Inhibit the synthesis of nucleic acid
Inhibit protein synthesis
72
What are the two groups of B lactams?
Penicillin
| Cephalosporin
73
What are the 2 groups of antibiotics that inhibit the synthesis of the cell wall?
B lactams
| Glycopeptides
74
What was the original penicillin?
Benzyl penicillin
75
Give 2 examples of glycopeptides?
vancomycin
| teicoplanin
76
What is vancomycin best for treating?
Gram negative bacteria
77
Who is vancomycin not suitable for?
Children
78
What are potential causes of acute inflammation?
```
Micro-organisms
Mechanical trauma
Chemical changes
Extreme physical conditions
Dead tissue - necrosis
Hypersensitivity
```
79
What happens to the blood vessels in inflammation?
Initially the vessels constrict - for protective reasons
| Then the vessels dilate
80
What does vasodilation cause?
An increase in blood flow to the area
81
What is the triple response?
Flush, Flare Wheal
82
What cells are involved in acute inflammation?
Neutrophils
83
What happens to vessel permeability in acute inflammation?
There is an increase in vessel permeability
84
What is exudation?
When there is movement from plasma into the ECM of plasma and proteins
85
Give examples of proteins that are in the exudate
Fibrinogen
| Immunoglobulin
86
What is fibrin?
A clotting factor
| A polymer of fibrinogen
87
What oedema?
The accumulation of exudate in the ECM
88
What does oedema cause?
Swelling reducing function and causing pain
89
What is margination?
Neutrophils move to the endothelial aspect of the lumen
90
What is Pavementing?
When neutrophils adhere to the endothelia
91
What is emigration?
When the neutrophils squeeze between endothelia to the outside tissue
92
What are the systemic effects of acute inflammation?
Pyrexia
Malaise
Neutrophilia (increased WBC)
Septic shock
93
What is angiogenesis?
When blood vessels form at the site
94
Why do capillaries grow into the inflammatory mass?
To allow the access of plasma proteins, macrophages and fibroblasts
95
What does granulation tissue eventually form?
A scar
96
What is bacteriamia?
When there is bacteria in the blood
97
What is septicaemia?
When there is the growth of bacteria in the blood
98
What is toxaemia?
When there are toxins in the blood
99
What cell types are involved in chronic inflammation?
Lymphocytes
Macrophages
Plasma Cells
Fibroblasts
100
What are the 2 major causes of chronic inflammation?
Progressing from acute inflammation
| Arising as a primary lesion
101
How does chronic inflammation arise from acute inflammation?
When there is a large volume of damage
There is the inability to remove the debris
Their is failure of the acute inflammation to resolve
102
When chronic inflammation arises from a primary lesion is there any acute phase?
No
103
What can primary chronic inflammation occur as a result of?
Autoimmunal disorder
Material resistant to cellular digestion
Exogenous substances
Endogenous substances
104
What factors can promote the healing and repair of chronic inflammation?
Cleanliness
Apposition of edges
Sound nutrition
Normal inflammatory and coagulation mechanisms
105
What factors can impair the healing and repair of inflammation?
Dirty gaping wounds
Poor nourishment (of vitamins ect)
Inhibition of angiogenesis
106
What Ab does type I hypersensitivity involve?
IgE
107
What is Type I Hypersensitivity commonly known as?
Allergy
108
What cells respond in type I hypersensitivity?
Mast cells
109
What happens during sensitisation in type I hypersensitivity?
The allergen is shown to T helper cell by an APC
| This causes B cells to differentiate to produce IgE against the antigen
110
What happens onwards from sensitisation in Type I hypersensitivity?
The bodies exposure t the antigen will cause the release of cytokines from mast cells causing an allergic response
111
Which antibodies are involved with type II hypersensitivity?
IgG and IgM
112
What is type II hypersensitivity hard to distinguish from?
Autoimmunity
113
Why is type II hypersensitivity hard to distinguish from autoimmunity?
Because the bodies antibodies bind to the antigens on its own cel surfaces
114
What are formed in type III hypersensitivity?
Immune complexes
115
What are immune complexes?
Clumps of antibodies that have stuck together
116
Where do the immune complexes go in type III hypersensitivty?
They are deposited in tissues
117
What is the effect of deposited immune complexes in the tissue?
Inflammation
118
What recognises the antigens in type IV hypersensitivity and what do they produce when recognised?
CD4 helper T cells
| Produce cytokines
119
What is the substance with the low m.w in type IV hypersensitivity known as?
Hapten
120
What is the hapten combined with?
Carrier protein
121
Why is the hapten combined with a carrier protein?
To produce sufficient antigenic bulk
122
What is an early phase response?
A response that occurs within minutes
123
What mechanism is used in early phase response?
The chemicals used are preformed in mast cells (histamine, heparin, chemotactic factors)
124
What mechanism is used in late phase response?
Newly synthesis mediators are involved
125
What is the effect of localised immune complex formation in type III hypersensitivity?
Local inflammation
126
What happens when there is systemic immune complex formation in type III hypersensitivity?
Complexes are deposited in tissues and organs such as the skin, joints, blood vessels and kidneys
127
What is an autoimmune disease?
A large group of clinical disorders by tissue organ damage mediated by incorrect immune mechanism targeted at self antigens
128
What factors are involved in the aetiology of autoimmune diseases?
Genetic factors
Hormonal factors
Environmental factors
Immune regulatory factors (the immune system is not working correctly)
129
What are the pathogenic mechanisms involved in autoimmune disease?
```
Cell mediated
Antibody mediated
Antibody + complement
Immune-complex mediated
Recruitment of innate compounds
```
130
Give an example of an autoimmune disease of joints
Rheumatoid Arthritis
131
What are the 3 main types of parasites?
Protozoa
Helminths
Arthropods
132
Give examples of arthropods
Ticks
Lice
Mites
133
What is the vector of malaria?
Female mosquito
134
Gives three examples of protozoa parasites
Malaria
Amoebic Dysentery
Leishmaniasis
135
Give an example of helminths
Tape worm
| Nematodes
136
In malaria what are injected under the skin?
Sprozoites
137
Where do sprozoites travel to and mature (malaria)?
Travel through the blood to the liver where they mature
138
When sprozoites have matured what do they re-enter the blood stream as?
Merozoites
139
What do merozoites in malaria go?
Re-enter circulation
| Invade and destroy RBC
140
Is there any cure for malaria?
No
141
What is the side effect of amoebic dysentery?
Diarrhoea with blood and pus
142
How many species of leishmaniasis are there?
Several
143
What do leishmaniasis causes?
Skin and mucosal ulceration
144
What does visceral leishmaniasis cause?
Fever, weight loss
145
What is leishmaniasis spread by?
Spread by sandfly bites
146
What occurs in late disease amoebic dysentery?
Liver abscesses
147
How do trophoziote ingest red cells?
By pseudopodia
148
Give an example of a trematode worm?
Schistosomiasis
149
Where are the eggs secreted in schistosomiasis?
Urine or faeces
150
What is the intermediate host in schistosomiasis?
Snail
151
In schistosomiasis what emerges from the snail 4-6 weeks later?
Cercaria
152
What is the definitive host in schistosomiasis?
Humans
153
Where does schistosomiasis migrate in humans?
Lungs to liver
154
Give examples of organ specific autoimmune diseases
Thyroid - thyrotoxicosis
Stomach - pernicious anaemia
Adrenal - addisons disease
155
Give examples of non-organ specific autoimmune diseases
Muscles - dermatomyositis
Skin - scleorderma
Kidneys - SLE
Joints- rheumatoid arthritis
156
Do drugs have to be lipophobic or lipophilic to cross the membrane?
Lipophilic
157
Why do drugs have to resemble the naturally occurring substance in active transport?
So they fit through the pumps by having a similar conformation to the naturally occurring molecule
158
Do highly lipid soluble drugs diffuse through the membrane?
Yes - readily
159
What do small changes in pH affect in drugs?
The ionisation and solubility
160
Do ionised drugs cross the membrane?
No
161
What happens to un-ionised drugs at the membrane?
They distribute across the membrane until equilibrium is reached
162
What factors affect the absorption of a drug in the GI tract?
Motility
Food
Illness
163
What is the effect of food on the absorption of a drug from the GI tract?
Can impair or enhance the action of the drug
164
What is the effect of motility on the absorption of a drug in the GI tract?
Will affect the speed at which the drug will reach the site of absorption
165
How do migraines affect the absorption of a drug from the GI tract?
Reduces the rate of stomach emptying
166
What is first pass metabolism?
The metabolism of the drug prior to it reaching the site of absorption
167
Where does first pass metabolism mainly occur?
Gut Lumen
Gut Wall
Liver
168
What is the bioavailability of a drug administered IV?
100%
169
Does IV have first pass metabolism?
No
170
Where are inhaled drugs mainly metabolised?
Lungs
171
Are small or large doses used in inhalation drugs?
Small doses
172
Is there much systemic absorption of drugs administered by inhalation?
Little systemic absorption
173
Does topical administration achieve local or systemic effects?
Both
174
Does topical administration go through first pass metabolism?
Yes
175
What is the bioavailability of a drug?
The amount of drug which reaches the circulation and is available for action
176
What affects a drug ability to cross the membrane?
Particle size
Lipid solubility
pH and ionisation
177
What factors determine the bioavailability of a drug?
Formulation
Drugs ability to pass physiological barriers
Gastrointestinal effects
First pass metabolism
178
Give an example of a plasma protein that a drug binds to?
Albumin
179
If a drug is bound to protein is it active?
No
180
Is plasma protein binding of a drug reversible?
Yes
181
For plasma protein binding to be important what percentage of the drug must be bound?
90%
182
What affects drug distribution?
```
Plasma Protein Binding
Tissue Perfusion
Membrane Characteristics
Transport Mechanisms
Diseases/Other Drugs
Elimination
```
183
What 3 reactions are involved in phase 1 metabolism?
Hydrolysis
Oxidation
Reduction
184
What does phase 1 metabolism increase?
The polarity of the compound
185
What does phase 1 metabolism provide for phase 2 metabolism?
An active site
186
What family of enzymes carry out phase 1 metabolism?
P-450
187
What are the 3 P-450 enzymes involved in phase 1 metabolism?
CYP3A4
CYP2D6
CYP1A2
188
Where is CYP3A4 found?
In the human layer
189
Give examples of drugs that are metabolised by CYP3A$
Diazepam
Methadone
Simvastatin
190
What does CYP2D6 metabolise?
Antidepressants, antipsychotics
191
What does CYP2D6 convert codeine to?
Morphine
192
In what percentage of the population does CYP2D6 have reduced expression?
5-10%
193
What is CYP1A2 induced by?
By smoking
194
What does phase 2 involve?
Conjugation
195
What does conjugation do?
Increases the water solubility of a compound
196
Why is increasing water solubility in conjugation important?
Makes secretion easier
197
What does phase 2 involve the attachment of to the metabolite from phase 1?
Glucuronic acid
Gluthianone
Sulphate
Acetate
198
Are all drugs inactivated by conjugation?
No but most are inactivated
199
What is enzyme induction in drug metabolism?
Many of the metabolising enzymes can be induced by other substances
200
What is the effect of enzyme induction?
More metabolising enzymes
| Decreased drug effect
201
What are the most common inducers of metabolising enzymes?
Alcohol
| Smoking
202
What does ethnicity affect in terms of drug?
Rarely they affect drug metabolism
203
How does genetics affect drug metabolism?
Drug metabolising enzymes are often expressed in different forms so differences in individual gene expression is common
204
Describe metabolising enzymes in foetuses and premature infants
The metabolising enzymes are often or reduced
205
Describe the renal function in premature infants and foetuses and its effect on drug metabolism
Renal function is deficient - which can lead to a build up of the drug - toxicity
206
By the age of 2 describe drug metabolism/
Drugs are metabolised faster than in adults
207
Describe enzyme inhibition in drug absorption
many commonly used drugs can inhibit the metabolising enzymes
208
Where are enteric tablets broken down?
In the small instetine
209
Why are tablets coated with enteric coating?
To protect the tablet from the stomach acid
| To prevent the stomach from the drug
210
What are the benefits of tablets and capsules?
They are convenient
They have an accurate dose
They have an ease of mass production
211
Are solutions/suspensions absorbed rapidly?
Yes
212
What does the absorption of solutions and suspensions depend on?
Gastric emptying
213
What drugs are suspensions good for?
Insoluble and unpalatable drugs
214
What percentage of inpatients suffer ADR's?
10-20%
215
What percentage of hospital deaths are due to ADR's?
0.25-3%
216
How many deaths per year are caused by drug ADR's?
5000-10000
217
What percentage of hospital admissions are due to ADR's?
6.5%
218
What do A ADR's stand for?
Augmented
219
Describe type A ADR's
Predictable
Dose dependent
Resolve when the drug is stopped
They ADR have been recognised before the drug is available
220
What does type B ADR's stand for?
Bizarre
221
Describe type B ADR's
Unpredictable
Rare
Can cause serious illness or death
It is unrelated to dose
222
What does type C ADR's stand for?
Chronic
223
Describe type C ADR's
They are related to dose
They are related to the length of treatment
It is semi-predictable
224
What does type D ADR's stand for?
Delayed
225
Describe type D ADR's
They occur years after treatment or in the children of the patient
226
What does type E ADR's stand for?
End of treatment
227
Describe type E ADR's
The effects causes when the dug treatment is stopped - especially suddenly (like withdrawal symptoms)
228
What does type F ADR's stand for?
Failure of treatment
229
Describe type F ADR's
They are common
| Frequently caused by drug interactions
230
What factor may predispose a patient towards drug-drug interactions?
Number of drugs on
The patients age
Wether the patient has a critical illness
Wether the patient is undergoing surgery
Whether the patient already has a chronic underlying condition
231
What is a drug interaction?
Defined as the modification of a drugs effect by prior or concomitant administration of another drug, herb, food or drink
232
What are the different types of drug interactions?
```
Drug interactions
Herbal interactions
Food interactions
Drink interaction
Pharmacogenetics interactions
```
233
What is the object drug?
The drug whose activity is effected by such an interaction
234
What do clinical test provide?
Evidence
235
What are the two reasons that drugs need to be tested?
For their efficacy (if they work)
| For their safety ( are they safe)
236
What is the exclusion criteria in drug trials?
Pregnant women
Children
Elderly
Seriously ill
237
What factors have to be taken into consideration when choosing patients for clinical trials?
Age
Race
Compliance
Sex
238
What are the control group given in a clinical trial?
Placebo
239
What do you compare a drug in a clinical trial with to test its efficacy?
A placebo
| With another drug
240
What basics have to be taken into consideration when doing a drug trial?
```
The time scale
The end result
The choice of control drug
The choice of patients
The exclusion criteria
The drug used
```
241
What do we have to consider about the drug used in a clinical trial?
Formulation of the drug
Dose of the drug
Frequency that the drug is given
242
What is a double blind trial?
Neither the doctor knows which of the drugs the subjects are getting (the drug or the control drug)
243
What is a single blind clinical trial?
When the patient doesn'tknow if they are receiving the drug or control but the doctor does know
244
What is a randomised clinical trial?
When the patients are assigned to a group at random to prevent bias
245
What is a placebo controlled clinical trial?
When half the subjects get basically nothing and the other half get the drug
Comparisons are made at the end of the trial
246
How many patients does Phase III of a clinical trial involve?
1000-3000
247
How many subjects does Phase I of a clinical trial involve?
100
248
How many subjects does a type II clinical trial involve?
Up to 500
249
What is a pilot study?
To test the design of the study
250
What are the disadvantages of a randomized control clinical trial?
Subjects may not represent general patient population
Twice as many people are needed for the study
Some physicians will refuse
Some patients will refuse
251
What is a superiority design?
Shows that the new treatment is better than the control or standard
252
How long can it take to get a chemical structure to a licensed drug?
10 years
253
What drugs will bypass phase I of the trial?
Cytotoxics
254
What type of subjects does phase I of a clinical trial use?
Volunteers
255
What does Phase II of a clinical trial confirm?
The kinetics and dynamics in patients
256
What does Phase III of a clinical trial establish?
The efficacy
| Evidence of safety will also be established
257
What does Phase IV of a clinical trial produce evidence for?
Long term safety
258
What does p<0.05 mean?
It means that there's less than a 5% chance your results were obtained by random chance or error
259
What shape does DNA have?
Double helix
260
What does a DNA nucleotide consist of?
Pentose sugar
Phosphate
Base
261
In what direction do the strands run in DNA?
One strand runs 5' to 3'
| One strand runs 3' to 5'
262
What does DNA replication issemi-conservative and bi-directional mean?
That one half of each DNA molecule is old and the other half is new
263
Are DNA strands created in the same or different direction?
Different
264
In what direction are DNA strands created?
In a 5' to 3' direction
265
Which enzyme unzips the DNA?
DNA Helicase
266
What enzyme adds new nucleotides in DNA replication?
DNA polymerase
267
Which enzyme joins the DNA fragments in the 3' to 5' strand?
DNA ligase
268
What is each set of 3 bases called?
Codon
269
What does each codon code for?
Amino acid
270
How many amino acids are there?
20
271
How many codon combinations are there?
64
272
Does one amino acid refer to one codon?
No more than one codon can refer to one amino acid
273
What amino acid has only one possible codon?
Methionine
274
What is the initiation codon of transcription?
Methionine
275
What codon stops transcription?
The termination codon
276
The process of introns being removed and exons remaining in tact is known as what?
RNA splicing
277
What sections of the RNA are spliced out?
Introns
278
What sections of the RNA are coding and so remain intact?
Exons
279
Once the mRNA has been produced what is added to the 5' end?
A cap
280
Once the mRNA has been produced what is added to the 3' end?
A tail
281
Where does translation occur?
Endoplasmic reticulum
282
What does tRNA stand for?
Transfer RNA
283
What is a germline mutation?
An inheritable mutation of gametes
284
What is a somatic mutation?
A mutation of the other body cells which wont be passed onto future generations
285
What is a silent mutation?
When one of the bases has be substituted but the codon still codes for the same amino acid meaning nothing has been changed in the sequence
286
What is a missense mutation?
When the correct amino acid is replaced by an incorrect amino
The polypeptide makes some sense but not the original sense 1
287
What is a nonsense mutation?
When the correct amino acid is replaced by a stop codon
| There is premature ending of the polypeptide sequence and it makes no sense
288
What is a frameshift mutation?
When a base is inserted or deleted
Consequently this cause all codons to shift
The whole sequence is changed
289
In what sections of chromosomes is DNA expressed?
Euchromatin
290
In what denser sections is the DNA inactive?
Heterochromatin
291
What proteins is DNA wrapped around?
Histone
292
What charge do histone proteins carry?
Positive
293
The DNA wrapped around histone forms what?
Nucelosomes
294
What are the tips of the arms of chromosomes called?
Telomeres
295
What are the 6 stages of mitosis?
```
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
```
296
What is mitosis?
The separation of the nucleus
297
What is cytokinesis?
The separation of the cytoplasm
298
What happens in prophase?
Chromosomes condense
Nuclear membranes disappear
Spindle fibres form from centrioles
299
What happens in metaphase?
Chromosomes align at the equator of the cell
Attached by microfilaments to each centriole
Here there is maximum condensation of the chromosomes
300
What happens in anaphase?
Sister chromatids separate at the centromere
Separate longitudinally
Move to opposite ends of the cell
301
What happens in telophase?
New nuclear membrane form
| Each cell has 46 chromosomes
302
What happens in cytokinesis?
The cytoplasm separates
| Forming 2 new daughter cells
303
How many sperm cells are formed per meiotic cycle?
4
304
Is there a higher chance for eggs or sperm to have mutations and why?
Sperm
| Because they undergo many more divisions than eggs
305
What is spermatogenesis?
The process of sperm production
306
When does spermatogenesis commence?
In puberty
307
What is oogenesis?
The process of egg division
308
When does oogenesis occur?
In early embryonic life
309
What is trisomy 21 more commonly known as?
Down's syndrome
310
With advancing age does chances of trisomy 21 increase or decrease?
Increase
311
What is trisomy 13 more commonly known as?
Patau Syndrome
312
What is trisomy 18 more commonly known as?
Edwards syndrome
313
What is the disease with one X chromosome?
Turner syndrome
314
What is the disease with XXY sex chromosomes?
Klinefelter snydrome
315
What is the prognosis for Edwards syndrome?
Most die within the first year or months of life
316
What is the prognosis for patau syndrome (trisomy 13)?
Very few survive beyond the first year of life
317
What is a trisomy mutation?
When there are 3 copies of the chromosome
318
What is a deletion mutation?
When a part of the chromosome deletes
319
What are the two types of inversion mutations?
Paracentric
| Pericentric
320
What is a paracentric mutation?
When a section of the DNA in the arm of the chromosome is inverted
321
What is a pericentric inversion mutation?
When a section of the DNA is inverted around the centromere of the chromosome
322
What is a robertsonian translocation mutation?
When one of the chromosomes ends up with 2 long arms
| When the other chromosome ends up with 2 short arms
323
What 2 groups of antibiotics inhibit the synthesis of the cell wall?
B lactams
| Glycopeptides
324
What are the 2 groups of B lactams?
Penicillin
| Cephalasporin
325
What are the 2 groups of glycopeptides?
Vancomycin
| Teicoplanin
326
What was the original penicillin?
Benzyl penicillin
327
What is a common problem with vancomycin?
Toxicity
328
Do gylcopeptides act on gram positive or negative?
Gram positive
329
What are the 4 groups of protein synthesising inhibitor antibiotics?
Aminoglycosides
Macrolides/Tetracyclines
Cyclic Lipopeptide
Oxazolidinones
330
Are aminoglycosides especially useful in the treatment of gram negative or gram positive bacterial infections?
Serious gram negative
331
What are macrolides a useful alternative to?
Penicillin - those with allergies
332
What is an autosomal condition?
One which affects any chromosome other than the sex chromosomes
333
How many copies of the affected gene are required to be affected in autosomal recessive conditions?
2
334
How many copies of the affected gene are required to be affect in autosomal dominant conditions?
1
335
In autosomal dominant inheritance which generations are affected?
Each generation is affected
336
In autosomal recessive inheritance which generations are affected?
Generations are usually skipped
337
What is the chance of inheriting the mutation in autosomal dominant?
50%
338
Why are X linked recessive conditions more prominent in men?
Because they do not have a second X chromosome to mask the affected gene
339
Who does Y linked inheritance affect?
Males only
340
Where does all mitochondrial DNA come from?
Maternal origin
341
Where does mitochondrial disease come from?
Maternal origin
342
What is P?
Dominant
343
What is Q?
Recessive
344
What are the factors assumed in an idea population of genetics?
```
Mutations are ignored
Migration is negligible
Population size is large
Mating is random
There are no selective pressures
```
345
In genetics why is the expected not always the same as the observed?
Because fertilisation is a random process
346
What does the classification of a tumour depend on?
The region where it is found
| If it is benign or malignant
347
What is a glandular benign tumour called?
Adenoma
348
Does mitosis involve recombination?
It can
349
What are the major eukaryotic histone proteins
H2A, H2B, H3 H4
350
What do fibroblasts do?
Produce collagen
351
What does histamine promote?
The relaxation of smooth muscle
352
Where do neutrophil polymorphs have a major role?
In acute inflammation
353
What is hypoxia?
Lack of O2 to tissues
354
What does hypoxia impair?
The healing of tissue
355
What two aspects of the human skeleton are useful in identifying sex in skeletonisation?
Skull and pelvis
356
How is the age of the dead approximated in children?
Assessment of the epiphyses
357
What bones are the most useful for the calculation of height?
Lower limb
358
What information can be useful for personal identification?
Fingerprints
Dental records
DNA
359
For the terms of this what is death defined as?
The irreversible failure of the cardiovascular system
360
When the cardiovascular system fails what happens?
There is failure of O2 delivery resulting in tissue death
There is no blood pumping
The immune system ceases
361
What is the best opportunity for timing of death?
First 18 hours
362
What is the rule of thumb for the cooling after death?
1 degree per hour
363
What is rigor mortis?
The stiffening or shortening of muscle fibres leading to the rigidity of the muscles and the fixation of the joints
364
Is there any particular method that is good for determining time of death?
No
365
What does hypostasis represent?
The pooling of stagnant blood in dependant regions of the body under the influence of gravity
366
What is putrefaction?
Caused by the action of bacterial micro-organisms when the organism start to decay away at the body
367
Who is more affected in X-linked recessive inheritance?
Males more than females
368
Why are males more affected in X-linked recessive inheritance?
Because they only have one copy of the X chromosome
369
Why can males not transmit X linked recessive to sons?
Because males pass on their Y chromosome to sons
370
Why can males not transmit X linked dominant to sons?
Because males pass on their Y chromosomes to sons
371
In autosomal dominant inheritance what is the chance of inheriting the mutation?
50%
372
Who does Y linked inheritance affect?
Males only
373
Why does Y linked affect males only?
Because only males have a Y chromosome
374
What is mitochondrial inheritance disease a form of?
Maternal inheritance
375
Why is mitochondrial disease a form of maternal inheritance?
Since all mitochondrial DNA comes solely from the mother
376
What is anticipation?
The diseases are spotted in earlier generations and increase with severity in later ones
377
What is genetic penetrance?
The frequency with which a trait is manifested by individuals carrying the gene
378
With the gene CFTR and the disease cystic fibrosis what is the penetrance?
100%
379
With the gene BRCA1/2 and the disease breast cancer what is the penetrance?
70-80%
380
With the gene BRCA1/2 and the disease ovarian cancer what is the penetrance?
50%
381
What is cystic fibrosis caused by?
A mutation in CFTR
382
What environmental can affect the severity of disease?
```
Lifestyle
Diet
Smoke
Alcohol
Drugs
Stress
Air pollution
Chemicals
Infection
```
383
What is epigenetic modifications?
Heritable changes in gene function that cannot be explained by changes in DNA sequence
384
Why are mitochondria a mutation hotspot?
Lack of efficient DNA repair system
Lack of protective proteins such as histones
Damaged by reactive oxygen species
100-fold higher than nuclear genome
385
Give examples of anticipation diseases?
Huntington's disease
Myotonic dystrophy
Fragile X syndrome
386
Describe myotonic dystrophy
Autosomal dominant disorder
Severe distal muscle weakness
Age of onset decreases with successive generations
Learning difficulties
387
What are proto-oncogenes?
Genes that code for cell growth and regulation
388
What are oncogenes?
They do not regulate growth and just accelerate it forming a tumour
389
What is a tumour suppressor gene?
Genes that act as the brakes for cell growth
390
How do tumour suppressor genes act as brakes for cell growth?
They can inhibit the cell cycle
| Or promote apoptosis
391
Describe the double hit hypothesis
Both a proto-oncogene and tumour suppressor gene are hit by mutations
392
What are the purine bases?
Adenine
| Guanine
393
What are the pyrimidines bases?
Thymine
| Cytosine
