ICS Flashcards

1
Q

what are the 2 types of autopsies?

A
  1. hospital
  2. medico-legal (coronial and forensic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the 2 types of medico-legal autopsies?

A
  1. coronial (lawful death)
  2. forensic (non-lawful death)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

which type of autopsy is most common?

A

medico-legal: coronial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does a hospital autopsy require?

A

MCCD (medical certificate of cause of death?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are hospital autopsies used for?

A
  • teaching
  • research
  • governance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when are coronial autopsies conducted?

A

when death is lawful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

when are forensic autopsies conducted?

A

when there’s a non lawful death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the 4 questions of the coroner?

A
  1. who was the deceased?
  2. when did they die?
  3. where did they die?
  4. how did they come about their death?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does an autopsic pathologist have the same role as?

A

the coroner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are 3 types of deaths referred to a coroner?

A
  1. presumed natural
  2. presumed iatrogenic
  3. presumed unnatural
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does iatrogenic mean?

A

caused by medical exam/treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the no. of days where if not seen by a doctor, a presumed natural death is referred to a coroner?

A

14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the most common referral reason for autopsy?

A

presumed natural death - not seen doc in last 14d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are examples of iatrogenic deaths? (4)

A
  1. peri/post-op deaths
  2. anaesthetic deaths
  3. illegal abortion
  4. complications of therapy (even if recognised)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

name some examples of presumed unnatural deaths (4)

A
  1. industrial deaths eg asbestos
  2. suicide
  3. unlawful killing
  4. custody deaths
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

do docs have a statutory duty to refer deaths to coroners?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

who has a statutory duty to refer deaths?

A

registrar of BDM (births, deaths n marriages)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

who else can make referrals for autopsy?

A

relatives, police etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

who performs coronial autopsies?

A

forensic pathologists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

who performs majority of autopsies (hospital)????

A

histopathologists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 5 steps to an autopsy?

A
  1. history/scene
  2. external examination (formal identifiers etc)
  3. evisceration (removal of external organs)
  4. internal examination
  5. reconstruction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what happened in oct 2016 relating to autopsies?

A

digital - full body CT scan reported by consultant radiologist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

define coronial autopsy

A

systematic scientific exam that helps coroner determine who the deceased was, when and where did they die and how they came about their death?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

define acute inflammation

A

the initial and often transient series of tissue reactions to injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how **long** does **acute inflammation** often last?
few hours to a few days
26
what is an example of acute inflammation?
appendicitis
27
what is inflammation?
(hard to define): local physiological response to tissue injury *[often involves cells eg neutrophils n macrophages]*
28
is inflammation a disease?
no, but usually a manifestation of disease
29
what are the benefit(s) of inflammation? (2ish)
* destruction of invading microorganisms and wailing off of an abscess cavity * PREVENTING infection spread
30
what are the negatives of inflammation? (3)
- autoimmunity *eg rheumatoid* *arthiritis* - when it's an over-reaction to the stimulus - fibrosis resulting from chronic inflammation may distort tissues and alter their function
31
list 6 causes of inflammation :/
1. microbian infections 2. hypersensitivity reactions 3. physical agents 4. chemicals 5. acids/alkalis 6. tissue necrosis
32
list 4 macroscopic (n essential) appearances of acute inflammation
1. redness *[rubor]* 2. heat *[calor]* 3. swelling *[tumor]* 4. pain *[dolor]*
33
what is rubor?
redness ## Footnote *1 of the 4 classical signs of acute inflammation*
34
what is calor?
heat, ## Footnote *1 of the 4 classical signs of acute inflammation*
35
what is tumor?
swelling, ## Footnote *1 of the 4 classical signs of acute inflammation*
36
what is dolor?
pain, ## Footnote *1 of the 4 classical signs of acute inflammation*
37
why is there heat/calor in acute inflammation?
increased blood flow (AKA hyperaemia) --\> vascular dilation
38
what is hyperaemia?
increased blood flow
39
why is there swelling/tumor in acute inflammation?
* swelling is from oedema/physical mass of inflammatory cells * formation of new connective tissue also contributes to swelling
40
why is there pain/dolor in acute inflammation?
* stretching/tissue distortion due to inflammatory oedema * AND pus under pressure in abscess cavity * (also some chemical mediators eg bradykinin, prostaglandins are known to induce pain)
41
what are 3 features of **chronic inflammation**?
1. slow onset/sequel to acute 2. long duration 3. may never resolve
42
what are 3 features of **acute inflammation**?
1. sudden onset 2. short duration 3. usually resolves
43
list 6 cells involved in inflammation
1. neutrophil polymorphs 2. macrophages 3. lymphocytes 4. endothelial cells 5. fibroblasts
44
discuss neutrophil polymorphs (5)
* short-lived cells * first on scene of acute inflammation * cytoplasmic granules full of bacteria-killing enzymes * usually die at scene of inflammation * release chemicals that attract other inflammatory cells eg macrophages
45
which wbc is short lived?
neutrophils
46
which cells are first on scene at acute inflammation?
neutrophils
47
do neutrophils die at scene of inflammation?
usually
48
what do neutrophils release?
chemicals that attract other inflammatory cells eg macrophages
49
what is the **life span** of macrophages?
long lived compared to neutrophils - *weeks to month*s
50
what do macrophages do?
* ingest bacteria n debris * may carry debris away * may present antigen of lymphocytes
51
what are kupffer cells an example of?
macrophages
52
what is the lifespan of lymphocytes?
years
53
what do lymphocytes do? (2)
* produce chemicals which attract other inflammatory cells * have an immunological memory for past infections and antigens
54
what do endothelial cells do? (4)
* line capillary blood vessels in areas of inflammation * become sticky in areas of inflammation so inflammatory cells adhere to theme * become porous to allow inflammatory cells to pass into tissues * grow into areas of damage to form new capillary vessels
55
what do fibroblasts do and what is their lifespan like?
- form collagen in areas of chronic inflammation and repair - *they are long-lived cells*
56
where are inflammatory cells?
in bone marrow, released into blood
57
what is the best known chemical mediator in acute inflammation?
histamine
58
name an example of chronic inflammation
tuberculosis
59
discuss tuberculosis (5)
1. no initial acute inflammation 2. mycobacteria ingested by macrophages 3. macrophages often fail to kill the mycobacteria 4. lymphocytes and macrophages appear 5. fibrosis occurs
60
what are granulomas?
- collection of macrophages - surrounded by lymphocytes?
61
list 3 medications for inflammation
1. aspirin 2. ibuprofen 3. steroids
62
what is resolution? (2)
* initiating factor removed * tissue undamaged or able to regenerate
63
what is repair? (2)
1. initiating factor still present 2. tissue damaged and unable to regenerate
64
which organ is a good example for resolution?
liver
65
what can a paracetamol OD result in?
liver failure
66
how does alcoholism impact regeneration?
bc of ongoing damage which results in abnormal architecture (cirrhosis)
67
can pneumocytes that line the alveoli regenerate?
yh
68
what are the most superficial skin wounds & an example?
abrasion *eg road rash from cycling*
69
what happens during abrasion?
only top cell layer is removed, leaving the bottom layer/follicles/glands for scab to form and for the epidermis to eventually be regenerated
70
what are the 2 types of skin would healing?
healing by 1st n 2nd intention
71
what is healing by 1st intention?
* edge to edge healing (heals w/ reasonable scar) * both ends are sealed together, the slight gap is filled w blood, fibrin etc which holds together a little w stitches * epidermis regrows, fibroblasts produce collagen * scar line is stronger than surrounding tissue as more blood vessels are grown
72
do scars along skin creases heal better or worse?
better
73
what does healing by 2nd intention usually involve?
traumatic wound where u can't bring 2 edges together
74
what forms initially during healing by 2nd intention?
granulation --\> epithelium slowly grows in from edges (depending on wound size)
75
define repair
replacement of damaged tissue by fibrous tissue
76
what is damaged tissue replaced by?
fibrous tissue
77
what is collagen prod by?
fibroblasts
78
after a MI, what is there where dead heart tissue was?
a fibrous scar
79
what does MF stand for?
myocardial fibrosis
80
what type of scar does MF (myocardial fibrosis) result in?
a dense white fibrous scar *(patient may live for a few months but may die after)*
81
which type of healing is preferred?
healing by 1st intention
82
if healing by 2nd intention, we don't want infection... what may be done to reduce this?
artificial skin dressings to keep the skin moist so it doesn't dry out - sometimes may have growth factors in them
83
what is fibrosis in the brain called?
gliosis
84
what is gliosis?
fibrosis in the brain
85
is gliosis contagious?
not as much as usual fibrosis
86
how does stroke recovery happen?
only the injured (not dead tissue) around the edge of the infarct gets better, with plasticity involved
87
list some cells that regenerate (5)
1. hepatocytes 2. pneumocytes 3. all blood cells 4. gut and skin epithelium 5. osteocytes
88
what are some cells that don't regenerate?
1. myocardial cells 2. neurones
89
what can venous thrombosis potentially cause?
pulmonary embolism
90
what is clotting within an intact vascular system aka
thrombosis
91
what is thrombosis within the arterial system usually due to?
damage to the vessel wall (which is often due to the formation of atherosclerotic plaques)
92
how does platelet aggregation happen?
when atherocsclerotic plaques rupture, then connective tissue collagen is exposed to the blood leading to platelets attaching to it
93
what can platelet aggregation activate?
the blood clotting system leading to an occlusion of the vessel
94
what does occlusion of a coronary artery result in?
death of heart muscle due to lack of blood flow (MI)
95
what does occlusion of a cerebral artery result in?
death of brain tissue due to a lack of blood flow (CI)
96
what is a stroke aka?
cerebral infarction (CI)
97
why does thrombosis in the veins most commonly occur?
due to slow blood flow within those veins eg when a patient is lying in bed for long periods of time after a major op
98
list some preventions of DVT in hosp (3)
1. early mobilisation 2. use of small doses of anti-coagulants eg heparin 3. venous stocking to prevent leg veins being full of blood
99
what is heparin?
an anti coagulant
100
what are the 2 reasons why clots are rare?
1. laminar flow 2. endothelial cells not sticky when healthy
101
what is laminar flow? and why is it important?
cells travel in the centre of arterial vessels and don't touch arteries - **this is important in reducing risk of blood clots**
102
define thrombosis
the formation of a solid mass from blood constituents in an intact vessel in a living person
103
what is the first stage of thrombosis?
platelet aggregation
104
how do platelets cause other platelets to stick to them? (which also starts clotting cascade off)
they release chemicals
105
why is platelet aggregation and clotting cascade difficult to stop?
both pos feedback loops
106
what is the name of the large protein molecule formed once the clotting cascade has begun?
fibrin
107
what does fibrin do?
makes a mesh in which rbc can become entrapped
108
define embolism
the process of a solid mass in the blood being carried through the circulation to a place where it gets stuck and blocks the vessel (most commonly a thrombus) could also be a bubble of air/fat/foreign etc
109
what are some less common causes of embolus? (4)
1. air (pressurised systems of IV fluids/blood in infants n kids esp) 2. tumour 3. amniotic fluid 4. fat
110
if an embolus enters the venous system, where will it lodge?
it will travel to the vena cava --\> through RHS of heart --\> &will lodge in pulmonary arteries
111
why can't an embolus in the venous system get through to arterial circulation?
bc the blood vessels in the lung split down to capillary size so lung acts as a filter for any venous emboli
112
what acts as a filter for venous emboli?
lungs
113
what happens if an embolus enters the arterial system?
it can travel anywhere downstream of its entry point eg a mural thrombus overlying a myocardial infarct in LV can go anywhere in systemic circulation
114
define ischaemia
a reduction in blood flow to a tissue without any other implications
115
define infarction
reduction in blood flow to a tissue that is so reduced it cannot even support mere maintenance of the cells in that tissue so they die
116
what is infarction usually caused by?
thrombosis of an artery eg thrombosis in LAD coronary artery causing infarction of anterior wall of LV
117
what is the triad of factors impacting thrombosis?
**Virchow's triad** 1. change in vessel wall (endothelial injury) 2. change in blood flow (stasis of blood flow) 3. change in blood constituents (hypercoagulability)
118
what does end arterial supply mean?
most organs only have a single artery supplying them so they are very susceptible to infarction if this supply is interrupted
119
name some organs which don't have end arterial supply (3)
* liver: portal venous and hepatic artery supplies * lung: pulmonary venous and bronchial artery supplies * brain: around COW w multiple arterial supplies
120
what do endothelial cells act as?
a teflon coating
121
what can injury lead to exposure of?
collagen
122
what does fibrinogen get activated by?
chemicals the platelets release
123
an LAD CA thrombus can led to an MI. how will this present on ecg?
ST elevation on chest leads
124
how does cigarette smoke change vessel walls?
kills endothhelial cells
125
why does CO inhalation result in an increased risk of thrombosis?
* inhaling lots of CO * --\> more rbc production * --\> more cells * = blood more turgid * --\> can thrombus more easily
126
how does atherosclerosis disrupt laminar flow?
makes artery walls sticky
127
what is aspirin in low doses daily good for?
inhibits platelet aggregation
128
what is the most common cause of an embolus?
broken off thrombus travelling in blood stream
129
what is significant about IV drug abusers?
* street heroin is often cut with talcum powder which isn't v soluble * --\> injected emboli into veins * --\> usually filtered in lungs, sometimes liver
130
above what ml of air can cause an embolus?
150
131
what is infarction a subset of?
ischaemia
132
what is the diff btwn ischaemia and infarction?
* ischaemia = any red in blood flow * infarction = death of cells due to lack of blood cells(?)
133
what causes atherosclerosis?
atheromas
134
define atheroma
pathology of arteries in which there is deposition of lipids in the arterial wall with surrounding fibrosis and chronic inflammation
135
what is the predominant cause of M/CI?
atherosclerotic plaques
136
list 3 risk factors for atheromas
1. raised serum lipids 2. hypertension 3. diabetes mellitus
137
what is the linkage between high serum lipids and atherosclerosis?
lipids cause endothelial damage
138
what is the major process after endothelial damage (and with which cells)?
chronic inflammation - with macrophages/fibroblasts
139
name 3 factors that can reduce endothelial damage
1. reduced lipids 2. lowered BP 3. stopping smoking
140
which drug can reduce the amount of platelet aggregation at the site of endothelial damage?
taking low dose aspirin
141
define atherosclerosis
narrowing of arteries due to plaque formation
142
what is the diff btwn atherosclerosis and arteriosclerosis?
* athero = narrowing of arteries due to plaque formation * arterio = hardening of arteries
143
define arteriosclerosis
hardening of the arteries
144
can u have a genetic predisposition to atherosclerosis?
yes
145
when is complicated atherosclerosis usually seen?
later in life
146
what is significant about atherosclerosis?
it is mostly based on incremental episodes of endothelial cell damage over a LONG period of time eg decades
147
what is in a plaque? (3)
1. quite a lot of fibrous tissue 2. lipids 3. lymphocytes (maybe also inflammation)
148
name 4 risk factors for atherosclerosis
1. smoking 2. hypertension 3. diabetes 4. increased deprivation :(
149
why does vaping have adv over smoking?
free radicals in cig smoke/CO/nicotine kills endothelial cells, vaping has fewer free rads and no CO
150
list the journey from smoking --\> chest pain
* smoking * endothelial cell damage * thrombus * heals bc endothelial cell layer grows over * small bump * not much impact * repeated endothelial damage * cycle continues w/o symptoms * symptoms may finally begin after years eg slight chest pain OR still asymptomatic
151
what are the symptoms of atherosclerosis in coronary arteries?
* vomiting * anxiety * angina * coughing * feeling faint
152
what can atherosclerosis in coronary arteries result in?
ischaemia of cardiac muscle cells
153
list some symptoms of atherosclerosis in carotid arteries
* weakness * dyspnea * facial numbness * paralysis
154
what is dyspnea?
shortness of breath
155
wich disease can atherosclerotic plaque also cause?
peripheral vascular disease
156
what are some symptoms of peripheral vascular disease?
* hair loss * erectile dysfunction * weakening of area
157
what are some symptoms of atherosclerosis in renal arteries?
* reduced appetite * hand swelling * renin release can be increased --\> BP may be sig increased
158
high or low amounts of circulating LDL can lead to endothelial dysfunction?
high
159
plaque formation steps?
?
160
define apoptosis
programmed cell death of a single cell
161
define necrosis
unprogrammed death of a large number of cells due to an adverse event
162
list some examples of adverse events that could result in necrosis?
* infarction * burns * frostbite * etc
163
which type of cell death is important in the normal function of the human body?
apoptosis?
164
why is apoptosis important in embryogenesis?
apoptosis removes cells that are no longer needed as organs develop eg tissue btwn fingers/toes so we dot s so that we dont end up w webbed feet n hands
165
what 2 things is apoptosis implemented by?
caspases and BCl2 protein
166
what can an aging or ill cell do besides apoptose?
* autophagy * closing down protein synthesis * cell cycle arrest
167
when can abomal apoptosis occur?
in a variety of situations inc: * drugs * graft vs host disease after bone marrow transplantation * neurodegeneration
168
thermal injury of a burn that physically causes the death of many cells is by what?
necrosis
169
what are condensed bodies in apoptosis aka
apoptic bodies
170
is apoptosis a well-coordinated process?
yes
171
are there any accompanying inflammatory reactions with apoptosis?
no
172
what does p53 protein detect?
dna damage in dividing cells
173
why do cancers get bigger?
bc apoptosis is lacking (often bc of a mutation in p53 gene so dna damage is not recognised)
174
why is apoptosis switched off in HIV?
as p53 is switched on to kill myphocytes?
175
what happens to the contents of cells in necrosis?
swelling and disintegration of small bodies of cell
176
list some examples of necrosis
1. frostbite 2. CI 3. avascular necrosis of bone 4. pancreatitis
177
where do congenital and acquired diseases tend to predominate?
congenital = paeds acquired = geriatric
178
where do autosomal diseases occur?
non-sex chromosomes
179
what is a congenital disease?
a disease that someone is born with (mostly genetic but can be acquired)
180
what is an acquired disease?
one that occurs after birth (often due to env, can be genetic)
181
name 2 prenatal factors, other than genetic abnormalities that can contribute to disease risk?
* transplacental transmission of env agents eg FA * nutritional deprivation
182
what is a genetic disease?
1 that occurs primarily from a genetic abnormality
183
what is caused by a point mutation in the beta-globin chain of Hb?
sickle cell anaemia
184
in sickle cell anaemia, when do the RBC deform/sickle?
when oxygen sat is low
185
single gene disorders are typically classified into what?
dominant or recessive
186
an single gene disorders be further classified?
autosomal (non-sex chromosomes) sex-linked (parts of x chromosome that dont have a corresponding region on y chromosome)
187
what type of disorder is breast cancer an example of?
polygenic disorders (bc BRCA1/BRCA2 do have a large individual efffect but mostly risk is composed of incremental rises in risks by 100s of unrelated genes)
188
what is the E4 apoprotein associated with?
high risk of ischaemic heart disease due to atheroma 3x higher in pop of papa new guinea than caucasians
189
what is spina bifida occulta?
malformation of 1+ vertebrae
190
GH excess is usually due to what?
pituitary tumour - adenoma
191
define adenoma
benign tumour formed from glandular structures in epithelial tissue
192
what does hungtington's disease result in?
death of brain cells early symptoms - subtle with mood/mental abilities general lack of coordination and unsteady gait often follow
193
what type of disorder is huntingtons?
inherited - autosomal dominant - gene called huntingtin (HTT) on chromosome 4... ≥36
194
increased cell growth is caused by which 2 processes?
hypertrophy and hyperplasia
195
define hypertrophy
when the SIZE of an individual cell/tissue/organ is increased by an increase in the SIZE OF THE CELLS without the increase number of cells
196
define hyperplasia
increased growth of cell/tissue/organ because of an INCREASE IN NUMBER OF CELLS. often accompanied by increase in cell size
197
bodybuilders prefer what? hypertrophy or hyperplasia
hypertrophy - increase in size of cells (appearance)
198
athletes prefer what? hypertrophy or hyperplasia?
hyperplasia - increased number of cells (or myofibrils in each cell, strength)
199
which 2 factors contribute to hypertrophy?
sarcoplasmic hypertrophy - focuses more on increased muscle glycogen storage myofibrillar hypertrophy - focuses more on increased myofibril size
200
how does hypertrophy/hyperplasia present in pregnancy?
hyperplasia - breast epithelial cells respond to increased demands uterus - both hypertrophy and hyperplasia
201
define atrophy
decrease in the size of cells caused by a decrease in NUMBER of cells OR decrease in SIZE
202
why might pathological atrophy happen?
bc of loss of blood supply, loss of innervation, pressure, lack of nutrition, lack of hormonal stimulation or bc of hormonal stimulation
203
define metaplasia
reversible transofrmation of 1 mature cell type in another fully differentiated cell type
204
what is an example of metaplasia in smokers?
transofmration of normal pseudostratified columnar ciliated epithelium of bronchi into squamous epithelium after repeated exposure to cig smoke
205
what is dysplasia?
an imprecise term forthe morphological changes seen in cells in the progression to becoming cancer it's a premalignant condition characterised by increased growth, cellular atypia and decreased differentiation
206
why does hearing loss occur in older age?
hair cells in the cochlear don't regenerate
207
list some examples of illnesses associated w/ ageing
osteoporosis cataracts dementia sarcopaenia (lack of muscle) deafness
208
what is the generic term for a malignant tumour?
cancer
209
how does basal cell carcinoma of the skin act?
only invades localy - can be locally excised and cured !
210
most carcinomas spread to where?
lymph nodes that drain the site of the carcinoma
211
what are 5 common tumours that spread to bone?
breast prostate lung thyroid kidney
212
what is the easiest way to confirm breast cancer?
small needle biopsy
213
what is a lumpectomy?
breast conserving surgery / partial masectomy / wide excision
214
what is the most widely used cancer staging system and what does it mean?
TMN system T = extent of tumoour M = presence of metastases N = spread to lymph nodes
215
what is the TNM staging converted to?
0 = carcinoma in situ 1-3 = size of cancer/nearby spread 4 = metastatic disease
216
define carcinogenesis
process which results in the transformation of normal cells to neopalstic cells due to permanent genetic alterations (mutations)
217
what does carcinogenesis only strictly apply to?
malignant tumours
218
what are carcinogens?
agents known/suspected to participate in the causation of tumours
219
how may env carcinogens be identified?
from epidemiological studies assessment of occupational risks direct accidental exposure experiemntal observations
220
what type of process is carcinogenesis? and why?
multistep - may require initiating and promoting agents - often resulting in a latent period btwn exposure to carcinogen and clinical recognition of a tumour
221
what is the diff btwn carcinogenic and ongogenic?
carcinogenic = cancer causing oncogenic = tumour causing
222
list some classes of carcinogens
1. chemical 2. viral 3. ionising and non-ionising radiation 4. hormones, parasites and mycotoxins 5. miscellaneous
223
what are some host factors for carcinogens?
race diet constitutional factors eg age/gender premalignant lesions transplacental exposure
224
what is a neoplasm?
a lesion resulting from the autonomous growth of cells which persists after the initiating stimulus has been removed
225
what are benign neoplasms like ?
generally slow growign closely resemble parent tissue remain localised
226
what are malignant neoplasms like?
have the capacity to invade surrounding tissues grow more rapidly show variable resemblance to parent tissue
227
all neoplasma are designated by which suffix?
"-oma"
228
benign connective tissue neoplasms have a prefix denoting what?
cell of orgin eg lipoma - benign neoplasm arising from adipocyte
229
malignant epithelial tumours = carcinomas malignant connective tissue neoplasms = ?
sarcomas
230
what are neoplasms made up of?
neoplastic cells and stroma
231
what is a stroma?
supporting networking cells
232
define angiogenesis
recruiting blood vessels to help and grow
233
how can neoplasms be classified behaviourally?
benign, borderline, malignant
234
why should we worry about "benign" neoplasms?
they cause morbidity and mortality through: - pressure on adjacent structures - obstruct flow - produce hormones - transform to malignant neoplasms - anxiety
235
how can neoplasms be classified histogenetically?
- specific cell of origin of a tumour - histopathological exam - specifieis tumout type
236
what is a papilloma?
benign tumour of non-glandular, non-secretory epithelium prefix with cell type of origin eg squamous cell papilloma
237
what is an adenoma?
benign tumour of glandular/secretory epithelium prefix with cell type of origin eg thyroid adenoma
238
name 2 benign epithelial neoplasms
papilloma adenoma
239
name 2 malignant epithelial neoplasms
carcinoma adenocarcinoma
240
what is the diff btwn carcinoma and adenocarcinoma?
carcinoma - malignant tumour of epithelial cells adenocarcinoma - carcinomas of glandular epithelum
241
all carcinomas are caused by malignancies of what?
epithelium
242
all sarcomas are malignancies of what?
connective tissue
243
what is invasion of tumours dependent upon?
decreased cellular adehesion abnormal (increased) cellular motility prod of enzymes w/ lytic effect on surrounding tissues
244
what is metastasis?
process by which a malignant tumour spreads from its primary site to prod secondary tumours at distant sites?
245
metastasis is dependent upon what?
a chain of events known as metastatic cascade (detachment, invasion, intravasion, evasion of host defences, arrest, extravasation, vascularisation)
246
what is the diff btwn carcinoma in situ and invasive carcinoma?
carcinoma in situ = can't metastasise, can be locally removed invasive carcinoma = worry of spreading
247
breast cancer is a malignant tumour arising from what?
the epithelial cells lining the ducts and lobules of the breast
248
name a popular anti-oestrogen drug?
tamoxifen
249
what are 2 ways of increasing tumour size?
cell division lack of cell death (apoptosis)
250
T cells originate from what and mature where?
originate from stem cells in bone marrow mature in the thymus travel to blood and lymph
251
does innate immunity depend on lymphocytes?
no, adaptive does
252
draw out the graph thing of what a multipotent stem cell differentiates into :)
253
polymorphonuclear leucocytes are mainly involved in what?
allergic reactions
254
when are neutrophils important and what for?
innate immunity phagocytosis
255
what are eosinophils mainly associated w?
parasitic infections and allergic reactions
256
what are basophils similar to? what are they mainly involved in?
mast cells immunity to parasitic infections/allergic reactions
257
when are monocytes important n what for ?
innate and adaptive immunity phagocytosis
258
how are monocytes and macrophages linked?
monocytes --\> macrophages once a monocyte leaves blood, it matures into a wandering/fixed macrophage
259
what do T cells expresss
CD3 - T cell receptor complex
260
what are complements?
group of ≈20 serum proteins that need to be 'activated' to be functional
261
what is epitope?
part of the antigen that binds to the antibody/receptor binding site
262
what is the most common Ig?
IgG
263
what are cytokines?
proteins secreted by immune and non-immune cells
264
what are interferons? (IFN)
induce a state of antiviral resistance in uninfected cells limit spread of viral infection IFNa&b - prod by virus infected cells
265
what are interleukins? (IL)
produced by many cells can be pro-inflammaotry (IL1) or anti-inflammatory (IL-10) can cause cells to divide, differentiate and secrete factors
266
what are tumour necrosis factors (TNF)
mediate inflammation and cytotoxic reactions potent
267
list examples of cytokines
IFN IL TNF
268
what 3 things does innate immunity include?
1. physical/chemical barriers 2. phagocytic cells (neutrophils and macrophages) 3. serum proteins (complement, acute phase)
269
what is inflammation?
a series of reactions that brings cells/molcules of immune system to sites of infection or damage
270
how is bacteria/funghi generally responded to?
phagocytosis killing
271
how are viruses generally handled?
cellular shut-down self-sacrifice cellular resistance
272
what is pattern recognition
recognition of microbes/viruses depends on seeing ancient, conserved features of them families of receptors exist to detect these in fluids, cell surfaces and compartments and intracellularly
273
what is an adjuvant?
a substane which enhances the body's immune response to an antigen
274
what are the 3 types of drug interaction?
synergy antagonism other
275
what are some risk factors for drug interaction?
patient wise: - polypharmacy - old age - genetics - hepatic/renal disease drug wise: - narrow therapeutic index - steep dose/response curve - saturable metabolism
276
what is the diff btwn pharmacodynamics and pharmacokinetics?
**pharmacodynamics** - what the drug does to the BODY *eg falling asleep, slower HR etc* **pharmacokinetics** - what the body does to the DRUG
277
the pharmacokinetics model of drug interaction looks at which 4 factors?
A - absorption D - distribution M - metabolism E - excretion
278
what is the biggest cause of OD in the world?
aspirin !
279
name a drug that causes LOTS of drug ineractiosn
warfarin !!!!!
280
what are the 3 traditional forms of vaccines?
live attenuated whole killed toxoids
281
what is passive immunisation?
transfer of preformed antibodies
282
define natural immunity
transfer of maternal antibodies across placenta to the developing foetus or via breast milk
283
what is artificial immunity?
treatment with pooled normal human IgG OR treatment with immunoserum against pathogens/toxins
284
what is inoculation?
introduction of viable microorganisms into the subject but basically inoculation = vaccination = immunisation
285
what are some advantages and disadvantages of whole live attenuated pathogen vaccines?
advantages - sets up transient infection - activation of full natural immune response - memory response (t/b cells) disadvantages - immunocompromsied - complications
286
what are some adv/disadv of whole killed, inactivated pathogens?
advantages - no risk of infection - storage less critical disadvantages - tend to just acivate humoral response (lack of t cell) - immune response may be weak w/o transient infection - repeated booster vaccinations required - patient compliance can be an issue
287
what are some advantages and disadvantages of subunit vaccines?
advantages - safe - only parts of pathogen used - no risk of infection - easy to store n preserve disadvantages - immune response less powerful - repeated vaccines
288
what is a drug?
chemical substance of known sturcture (other than nutrient/essential vitamin) which, when administered to an organism, produces a biological effect
289
what is the diff btwn pharmacodynamics and pharmacokinetics again?
dynamics - effect of drug on body. *dynamic effects that a drug may have !* kinetics - effect of body on the drug *- kinetically, the drug may behave in many diff ways*
290
what is a drug receptor?
biological term for recognition proteins of endogenous mediators
291
a drug which binds to a receptor is termed what?
ligand
292
what are the diff types of ligands?
agonists - initiate bio response antagonists - don't initiate bio response but prevent naturally occuring mediators from binding
293
what does efficacy refer to in drug use?
maximum response "drug required to prod 50% of max)
294
what are some types of ligands?
exogenous (drugs) endogenous (hormones, neurotransmitters etc)
295
what are some types of receptors? n what are receptors?
principal means by which chemicals communicate neurotransmitters, autacoids (local) eg cytokines/histamine, hormones
296
what are some types of receptors?
* ligand-gated ion channel * g protein coupled receptors * kinase-linked receptors * cytosolic/nuclear receptors
297
what is an example of a ligand-gated ion channel
nicotinic ACh receptor
298
which receptor is beta-adrenoceptors an example of?
g protein coupled receptors
299
name a kinase-linked receptor
receptors for growth factors
300
name a cytosolic/nuclear receptor
steroid receptor
301
what is diff btwn affinity and efficacy?
affinity is how well a ligand BINDS to the receptor efficacy is how well the ligand ACTIVATES the receptor
302
what are some receptor-related factors governing drug action?
affinity efficacy
303
what are some tissue-related factors governing drug action?
receptor number signal amplification
304
what is EC50?
conc required for half maximal response
305
sodium channels can be inhibited by afferent nerve fibres by local anaesthetics to what? (3))
to prevent pain in the heart to treat arrhythmia in the brai to treat epilepsy
306
which channels may be inhibited in vascular smooth muscle to treat hypertension?
calcium
307
potassium channels can be inhibited to treat what? (2)
arrhythmia diabetes
308
what are 3 main types of protein ports in cell membranes?
**uniporters:** use energy from ATP to pull molec in **symporters:** use movement in of 1 molec to pull in another molec against conc grad **antiporters:** 1 substance moves against grad using energy from 2nd substrance moving down its grad)
309
what are xenobioitcs?
compounds foreign to an organism's normal biochem, such as any drug or poison
310
what are the 2 key beliefs influencing patient adherence to med?
necessity beliefs: perceptions abt personal need for treatment concerns abt a range of potential adverse consequences
311
what are the 4 impacts of good doc-patient communication?
1. better health outcomes 2. higher adherence to therapeutic regimens 3. higher pt and clinician satisfaction 4. decrease in malpractice risk
312
what are the key principles of improving patient adherence?
1. improve communication 2. increase pt involvement 3. understand pt's perspective 4. provide info 5. assess adherence 6. review meds
313
what does drug elimination refer to?
the removal of a drug from the plasma compartment towards its eventual excretion from the body
314
what is pharmacology?
action of drugs in the body inc: absorption, distribution, metabolism, excretion
315
list 10 routes of drug admin
1. oral 2. IV 3. IA 4. IM 5. SC 6. inhalational 7. topical 8. SL 9. rectal 10. intrathecal (injection into spinal canal)
316
what is pinocytosis?
aka fluid endocytosis ingestion of liquid into a cell by the budding of small vesicles from the membrane
317
what is pKA of a drug?
pH at which half of substance is ionised n half unionised
318
what is the easiest and most convenient route for many drugs?
oral - large SA/high blood flow of S intestine --\> rapid.complete absorption
319
drug needs to be _____ soluble to be absorbed from the gut
lipid
320
what is 1st pass metabolism?
drug taken orally have to pass 4 major metablic barriers to reach circulation: 1. intestinal wall 2. intestinal lumen 3. liver 4. lungs
321
how do u avoid hepatic 1st pass metabolism
by giving drug to region of gut not drained by splanchnic eg mouth or rectum (GTN)
322
what is the fastest route for admin?
IV - 20-60 secs
323
what is the slowest route for drug admin?
transdermal (topical) - variable, mins to hrs!
324
what is cytochrome p450?
fam of membrane bound isoenzymes present in smooth ER, largely in liver tissue smoking/alcohol can induce p450 enzymes - more rapid drug metabolism
325
what are some naturally occuring opioids?
morphine codeine (weak)
326
how do opioids work?
- inhibit the release of pain transmitters at SC (sup colliculus? idk)/mid brain - modulate pain perception in higher centres - euphoria (changes emotional perception of pain)
327
what is potency?
whether a drug is strong/weak - relate sto how well the drug binds to receptor
328
what is tolerance?
down regulation of receptors with prolonged use need higher doses to achieve the same effect
329
what is the potential with opioid use?
respiratory depression addiction - esp when used for chronic stuff
330
what are the 2 main neurotransmitters?
ACh NAd
331
where are M1/M2 (muscarinic receptors) mainly found?
in the heart - their activation slows heart, so we can block these
332
where are M3 muscarinic receptors found
glandular and smooth muscle - cause bronchoconstriction, sweating,s salivary gland secretion
333
where are M4/5/ muscarinic receptors found?
CNS
334
how do u treat bronchoconstriction?
block M3 receptor - anti-cholinergics or anti-muscarinics short-acting: ipratropium bromide long-acting: LAMAs eg tiotropium
335
ACh is a major transmitter innervating what?
skeletal muscle
336
what are some side effects of anti-cholinergics?
in the brain - worsen memory, may cause confusion peripherally - constipation, mouth drying, vision blurring etc
337
what are inotropes?
group of drugs that alter contractility of the heart positive inotropes - incr FORCE OF CONTRACTION of the heart negative inotropes - weaken it
338
how do chronotropic drugs change the heart rate n rhythm?
affecting the electrical conduction system of heart n nerves that influence it eg by changing rhythm prod by SA node pos chronotropes INCR HEART RATE neg chronotropes DECR HEART RATE
339
what does alpha 1 activation cause?
vasoconstriction particularly in skin and splanchnic (abdo) beds good for septic shock treatment
340
beta 1 activation will do what to the heart?
incr HR chronotropic effects may incr risk of arrhythmias
341
when may beta blockers be used?
angina MI prevention high BP anxiety arrhythmias heart failure
342
what does propranolol do and what group of drugs does it belong to?
beta blockers blocks beta 1 n beta 2 - will slow HR, reduce tremor, may cause wheeze
343
what does atenolol do n what class of drugs does it belond to?
beta 1 selective main efects on heart beta blocker
344
what is eclampsia?
a cond in which 1+ convulsions occur in a pregnant woman suffering from high BP, often followed by coma
345
what is pre-eclampsia?
disorder of pregnancy - high BP and either large amts of protein in urine or other organ dysfunction
346
what is an allergic reaction?
an inappropriate immune response to an otherwise harmless substance
347
what are some skin clinical indications related to allergy?
eczema itching reddening
348
what are some airway clinical indications related to allergy?
excessive mucus production bronchoconstriction
349
what are some GI clinical indications related to allergy?
abdo bloating vomiting diarrhoea
350
what is anaphylaxis?
acute allergic reaction to an antigen EG bee sting, to which the body has become hypersensitive
351
what is atopy?
tendency to develop allergies
352
what is allergic rhinitis?
hayfever
353
how can anaphylaxis be treated?
adrenaline !
354
what is an adverse drug reaction?
unwanted/harmful reaction following admin of a drug under normal cond of use .. n its suspected to be related to the drug
355
when should an adverse drug reaction be suspected?
- symptoms soon after new drug started - symptoms after dosage increase - symptoms disappear when drug is stopped - symptoms reappear when drug is restarted
356
what are the most common drugs to have adverse reactions?
ABs anti-neoplastics CV drugs NSAIDs
357
what are some common ADR's?
confusion nausea balance issues diarrhoea/constipation
358
what are the 4 types of hypersensitivity?
t1 - igE mediated drug hypersensitivity t2 - IgG mediated cytotoxicity t3 - immune complex deposition t4 - t cell mediated
359
what happens in anaphylaxis?
occurs within mins, lasts 1-2hrs rash swelling of lips, face wheeze/SOB hypotension cardiac arrest vasodilation incr vascular permeability bronchoconstriction angio-oedema
360
what are some common drugs for anaphylaxis?
penicillin aspirin NSAIDs
361
how does adrenaline affect the heart?
vasoconstriction - incr peripheral vascular resistance, incr BP, incr coronary perfusion (alpha1-adrenoceptors) stimulation of beta1-adrenoceptors - positive inotropic and chronotropic effects reduces oedema/bronchodilates via beta2adrenoceptors
362
what do u do to a patient with suspected anaphylaxis?
immediately: lie flat, raise legs (if breathing not impaired) when skills/equipment available: - establish airway - high flow oxygen - IV fluid challenge monitor: pulse ox, ECG, BP
363
what does helminth mean?
parasitic worm
364
what is the pre-patent period in a worm infection?
interval btwn infection n appearance of eggs in stool
365
what are the 3 groups of worms (helminths)?
1. roundworms (nematodes) 2. flatworms, flukes (trematodes) 3. tapeworms (cestodes)
366
what is ascaris lumbricoides?
large roundworms found worldwide, mainly tropics children particularly prone
367
what is the only common helminth infestation in the UK
pinworm/threadworm
368
what is trichus trichirua?
the whipworm
369
what is schistosomiasis?
aka bilharzia - an infection caused by a parasitic worm that lives in fresh water in subtropical/tropical regions
370
what is mycobacteria?
a bacterium of a group which includes the causative agents of leprosy and tuberculosis
371
what happens in leprosy?
causes lots of deformation damages nerves loss of sensation: ppl get injured, may lose ends of digits/limbs etc
372
what is acid fast bacilli?
mycobacteria!
373
what can mycobacteria cause?
tuberculosis, leprosy
374
is mycobacteria easy to culture?
no, bc they are slow growing
375
name some viruses that can cause rashes
rubella measles parovirus
376
list 5 basic properties of viruses
1. grow only inside living cells 2. possess only 1 type of nucleic acid: RNA or DNA 3. no cell wall struc but have an outer protein coat 4. essentially inet outside the host cell 5. protein receptors on surface allow attachment to susceptible host cells
377
what are the 6 stages of virus replication?
1. attachment 2. cell entry 3. interaction w/ host cells 4. replication 5. assembly 6. release
378
list 5 ways in which viruses can cause disease
1. damage by direct destruction of host cells (influenza) 2. damage by modification of host cell structure/function (HIV) 3. damage involving over-reactivity of host as a response to infection (hep B/C) 4. damage through cell proliferation/immortalisation (HPV) 5. evasion of both EX/IC host defences (measles, Hep B/C etc)
379
what are the medically important pathogens?
streptococci staphylococci
380
what are the 3 structures of bacteria?
spherical - COCCUS rod-shaped - BACILLUS SPIRAL
381
what are 3 types of microorganism
bacteria viruses eukaryotic organisms
382
what colour is gram positive?
purple
383
what colour is gram negative bacteria?
pink / (red)
384
define pathogen
organism that is capable of causing disease
385
define comensal
organism which colonises the host but causes no disease in normal circumstances
386
what is an opportunist pathogen?
microbe that only causes disease if host defence are compromised
387
what is virulence/pathogenicity?
the degree to which a given organism is pathogenic
388
what is asymptomatic carriage?
when a pathogen is carried harmlessly at a tissue site where it causes no disease
389
what is haemolysis?
the ability of bacteria to break down RBC in blood agar
390
what is coagulase?
enzyme produced by bacteria that clots blood plasma
391
how can steph aureus be spread?
by aerosol (coughs/sneezes) and touch eg MRSA !
392
what are some infections caused by s.pyogenes?
wound infections tonsilitis/pharyngitis impetigo scarlet fever rheumatic fever
393
what can s.pneumoniae cause?
it's a normal commensal in oro-pharynx that can cause: pneumonia sinusitis meningitis
394
list some important gram-pos bacteria
s. aureus s. epidermidis s. pyogenes s. pneumoniaeviridans streptococci c. diptheriae
395
how can gram positive bacteria be spread?
aerosols surface-to-surface contact colonisation of prostheses
396
how can gram positive bacteria be managed?
antimicrobials vaccination
397
what is source of bacteraemia often?
infection of abdo organ also wounds, cystitis etc
398
what is the pathogenesis of salmonellosis
ingestion of contaminated food/water invasion of gut epithelium - s intestine intestinal secretory/inflammatory response etc
399
list some important gram negative bacteria
haemophilus influenzae h. influenzae bordetella pertussis (whooping cough) n. meningitidis (meningococcus) n. gonorrhoea (gonococcus) campylobacter (c. jejuni, c. coli) helicobacter pylori chlamydiae
400
what is the diff btwn yeast and mould?
yeast - small single celled organisms, divide by budding moulds - form multicellular hyphae and spores
401
define funghus
group of spore-producing organisms feeding on organic matter, inc moulds, yeast, mushrooms
402
what is a spore?
unit of sexual/asexual reproduction - may be adapted for dispersal/survival, often for extende dperiods of time, in unfavourable cond spores form part of life cycles of many plants, algae, fungi and protozoa
403
what is mucosal candidiasis?
thrush
404
the prodution of what, by t cells/macrophages, is important in controlling the spread of virus from 1 cell to another?
gamma-interferon
405
how are worms in the body killed?
eg schistosomes coated with IgG/IgE - recognised by eosinophils - release toxic substances to kill them
406
what are key attributes of pathogens?
infectivity virulence invasiveness
407
what is antigenic drift n what can it result in?
viral spontaneous mutations, occur gradually, giving minor changes - epidemics
408
what is antigenic shift n what can it result in?
sudden emergence of new subtype diff to that of preceding virus - pandemics
409
what do adhesins do
help bacteria bind to mucosal surfaces
410
what do pattern recognition receptors do (PRR)
recognise PAMPs (pathogen associated molecular patterns) but also damage associated molecular patterns from host cells
411
what is a protozoa?
single-celled eukaryote that commonly show characteristics usually associated with animals, most notably mobility/heterotrophy
412
what is african trpanosmiasis aka
sleeping sickness !
413
what is a chancre?
painless genital ulcer
414
what is american trypanosomiasis aka?
chagas disease
415
discuss faecal-oral transmission
occurs when bacteria/viruses found in stool of 1 child/animal are swallowed by another child
416
what can amoebiasis result in
dysentry colitis liver and lung abscesses
417
what is myalgia
muscle pains
418
what is a fancy word for high temp?
pyrexia
419
if there's fever and recent travel, question WHAT?
malarrrrrrrrrIA!
420
how is malaria transmitted?
bite of female anopheles mosquito
421
which plasmodium of malaria has the most severe disease?
plasmodium falciparum
422
what kind of infection is malaria?
protozoan - can have up to 1 yr incubatiionperiod
423
how do u diagnose malaria
blood film
424
what are malaria symptoms?
FEVER FEVER FEVER also: chills, headache, myalgia, fatigue, D&V, abdo pain
425
what are some signs of malaria?
anaemia jaundice hepatosplenomegaly (lack water fever)
426
what are some complications of malaria?
acute resp distress syndrome renal failure bleeding shock
427
what is hypovolaemic shock?
clinical state in which loss of blood/plasma causes inadequate tissue perfusion
428
what is clostrium difficile?
bacterium - can infect bowel n cause diarrhoea
429
how might bacteria resist ABs
mutations destroy ABs antigenic variation
430
what does MRSA stand for
methicillin resistant stapylococcus aureus
431
which factors should be considered when determining if ABs are safe for patient use?
- intolerance, allergy and anaphylaxis - side effects - age - renal and liver function - pregnancy n breast feeding - drug interactions
432
what are beta lactams?
cell wall (peptidoglycan) killers
433
name some causative organisms for hosp acquired infectiosn
staphyloccocus aureus (inc MRSA) streptococcus pyogenes (group A streptococcus)
434
what are key components of infection prevention n control?
infection prevention n control team ward teams microbio/virology labs etc
435
what is the major means of HIV transmission worldwide?
heterosexual intercourse other risk factors include: homosexual intercourse, IVDU, blood transfusions
436
when is HIV untransmittable?
when it's undetectable (so if ur HIV+, take treatment, maintain undetectable viral load - can have sex knowing u won't pass it on)
437
what treatment is there for HIV?
HAART - highly active antiretroviral treatment
438
in HIV how do u measure how well the immune system is doing?
CD4 count
439
what are some methods of HIV prevention?
circumcision PEP STI control vaccines diagnosis/partner notif HAART treatment as prevention screen blood prods/needle exchange
440
maintain a high index of HIV suspicion if what?
prolonged episodes of herpes simplex persistent thrush oral thrush recent/worsening skin conditions unexplained weight loss
441
what is HIV caused by?
HIV-1 or HIV-2
442
what happens in HIV?
decrease in number of CD4 t-lymphocytes by a number of related mechanisms including cell death by apoptis sand increased trapping of cells in lymphoidal tissue
443
after a HIV infection, there is a variable period of \_-\_ months before the antibody test is positive
3-6
444
what is the approx HIV clinically latent period before ppl start getting unwell?
≈ 7 years
445
on presentation of antigen, CD4 cells mature in 2 types of helper cells... waht do these then prod?
Th1 - prod specific interleukins (IL4, 5, 10, 13) Th2 - prod IFN alpha and TNF
446
what are the 9 steps of HIV replication?
1. attachment 2. entry 3. uncoating 4. reverse transcription 5. genome integration 6. transcription of viral RNA 7. splicing of mRNA and translation into proteins 8. assembly of new virions 9. budding
447
how does the immune system respond to HIV? (draw the graph LOL)
448
what is shingle in HIV patients like?
usually more severe can be multidermatomal usually occurs in elderly
449
when is a HIV patient said to have AIDS?
when CD4 count \< 200 or when "AIDS defining illness" is present
450
what are the 3 stages of a HIV/AIDS epidemic?
1. **nascent**: HIV prevalence less than 5% 2. **concentrated**: prevalence has surpassed 5% in 1+ high risk populations, but prevalence among women attending urban antenatal clinics still less than 5% 3. **generalised**: HIV has spread far beyond original subpopulations - prevalence among women attending urban atenatal clinics is 5%+
451
why does circumcision lower the risk of HIV?
1. reduced ability of HIV to penetrate due to keratinisation of inner aspect of remaining foreskin 2. inner part of foreskin contains langerhan cells: prime targets for hiv. these are removed w/ foreskin 3. ulcers (characteristics of some STI's that ca facilitate HIV transmission) often occur on foreskin 4. foreskin may suffer abrasions/inflammation during sex that could facilitate the passage of HIV
452