Medical Imaging to Pharmacology and Treatment of Disease Flashcards
1
Q
which form of imaging is non-ionising?
A
MRI
2
Q
what are baroreceptors?
A
mechanoreceptors located in the carotid sinus and in the aortic arch. their function is to sense pressure changes by responding to change in the tension of the arterial blook
3
Q
where is the glucose sensor?
A
specialised pancreatic cells that receive blood via portal circulation
4
Q
what part of the motor system maintains glucose homeostasis?
A
autonomic nervous system
5
Q
where are the glucose homeostasis effectors?
A
alpha pancreatic cells in the islets of Langerhans (which secrete glucagon)
beta pancreatic cell which secrete insulin)
6
Q
what is gain?
A
the effectiveness of a negative feedback system
= correction/error
Correction: the amount of change
error: the amount over/under shot by the change
7
Q
if the effects brings the system back to normal the gain will be…
A
0
8
Q
what is the response of a non-excitable cell to a current being injected into the cell?
A
small depolarisation before the cell the repolarises and returns to the resting membrane potential
9
Q
what is flux?
A
the number of molecules crossing the unit area of membrane in unit time e.g. moles/cm/sec
10
Q
flux equation?
A
F=P(Co-Ci)
11
Q
what is an aquaporin?
A
protein channel specifically designed to allow water to cross the membrane.
basic aquaporin unit comprise 6 transmembrane alpha-helices
12
Q
describe the effect of ADH on the AQP-2 in the nephron ?
A
adh increase water re-adsorption in the kidney by up-regulating AQP-2 channels in the epithelial cells of the late distal tubules, collecting tubules and collecting ducts (reduce urine output) whilst the AQP 3 channels remain constant.
13
Q
what is the Therapeutic index?
A
dose producing toxicity in 50% of the population/ minimum effective dose for 50% of the population
14
Q
What can happen to patients on digoxin (narrow therapeutic index) who start diuretics?
A
They may become hypokalaemic. A reduction in competition between K+ and digoxin results in increased digoxin binding to the sodium pump. Because of the very narrow therapeutic index, the patient develops digoxin toxicity
15
Q
What is primary transport?
A
active transport systems directly couple the hydrolysis of ATP to molecule movement
16
Q
what is secondary transport?
A
active transport systems use the energy stored in the Na+ gradient (generated by the sodium pump) to drive molecular transport against the electrochemical gradient
17
Q
Explain sodium dependant calcium transport?
A
Protein drives sodium in at the expense of driving something out.
18
Q
what is GLUT2?
A
the glucose transporter that aids the Na+ dependent glucose transport.
An example of secondary active co-transport.
the glucose and Na move in the same direction (into the cell)
19
Q
what are the determinants of health?
A
fundamental conditions and resources for health: - peace shelter education food income stable eco-system sustainable resources social justice and inequity
20
Q
what are the acceptable health inequalities?
A
Ones that are attributable to biologica variations or free choice
ones that are a result of difference in mobility between elderly people and younger population
21
Q
what are the unacceptable health inequalities?
A
health inequalities that are:
- attributable to the external environment and conditions are mainly outside of the individuals control
- differences in mortality rates between people from different social classes
22
Q
difference examples of disease transmission?
A
infectious diseases
chemicals and poisons
radiation
environmental health hazards
23
Q
different types of occurrence?
A
sporadic, endemic, epidemic and pandemic
24
Q
what is sporadic occurrence?
A
occasional cases occurring irregularly
25
what is endemic occurrence?
persistent background level of occurrence
26
what is epidemic occurrence?
occurrence in excess of the expected level during a given time period
27
what is pandemic occurrence?
epidemic occurring in or spreading over several countries
28
at which concentration of extracellular K+ does the membrane potential equal approximately 0mV
140mM
29
which phase of the action potential involves the sodium pump?
not involved in any stage
30
which intracellular second messenger is responsible for triggering the insertion of AQP channel in the kidney?
cAMP
31
what property of the cell membrane generates a negative electrical potential inside the cell
the sodium-potassium pump
32
when is the embryonic period of development complete?
8 weeks after fertilization
33
What is meta-analysis?
A meta-analysis is when results of the individual studies are combined to produce an overall statistic.
best form of clinical evidence
34
which region of the embryo is in the closest contact with e endometrial cells?
syncytiotrophoblast
35
At which stage of development does the embryo reach the uterus?
morula
36
difference between bacterial and human ribosomes?
humans have larger ribosomes: 40S/60S vs 30S/50S
37
what do aminoglycosides do?
inhibit the activity of the bacterial ribosomes
38
target of penicillin's?
peptidoglycans of cell wall
39
target of Fluroquinolones?
Act by inhibiting bacterial DNA topoisomerase II also known as DNA gyrase
40
antibiotics involved which act as Bacterial Folate Antagonists?
SULPHONAMIDES AND TRIMETHOPRIM
41
What do SULPHONAMIDES AND TRIMETHOPRIM do?
- These are antibiotics which act through an inhibition of the folate pathway in bacteria
- The folate system is important in cell metabolism
- Bacteria have to make their own supply since you cannot get it from your diet. This makes bacteria susceptible to drugs which interfere with folate metabolism: thus we have out selective toxicity target
42
what is epidemiology?
the study of the distribution and determinant of health-related states and events in specified populations and the application of this study in the control of the problems
43
what makes statistics meaningful?
a denominator population
| a time frame
44
difference between incidence and prevalence?
incidence in the rate of new cases whilst prevalence is the proportion of the population that is infected.
45
what are the three categories of exposures and give one example for each?
modifiable - smoking
non-modifiable- gender
interventions- drug therapy
46
how to calculate risk?
(number of outcomes/number of people in group) x 100
47
how to calculate risk ratio?
risk in exposed/risk in unexposed
48
how to calculate absolute risk reduction (risk difference) ?
risk in unexposed - risk in risk in exposed
49
how to calculate relative risk reduction?
(1-risk ratio) x 100
50
how to calculate number needed to treat?
1/absolute risk reduction
51
what is confounding?
when the true relationship is confused by a third factor
52
name the different potential causal links?
STRENGTH: A causal link is more likely with strong associations
CONSISTENCE: A causal link is more likely if the association is observed in different studies and different subgroups
SPECIFICITY: A causal link is more likely when a disease is associated with one specific factor
TEMPORALITY
BIOLOGICAL GRADIENT: A causal link is more likely is different levels of exposure led to a different level of acquiring the outcome
PLAUSIBILITY: A causal link is more likely when a biologically plausible mechanism is demonstrated
CONHERENCE
EXPERIMENT: A causal link is very likely if removal of the factor leads to a reduced risk of acquiring the outcome
ANALOGY
53
what is health promotion?
the process of enabling people to increase control over and to improve their health
54
name 3 downstream and 3 upstream influences of health?
```
DOWNSTREAM
Personal strengths or vulnerabilities
Behaviours
Individual determinants "immediate causes"
UPSTREAM
Social determinants "causes of causes"
population wide influences
international, political and economic forces
```
55
name the 5 approaches to health promotion
e.g. smoking
Medical approach: encourage non-smoking, education
Behavioural change: persuasive education
Educational approach: health risks, how to stop
Empowerment approach: community identify what can be done to stop smoking
Societal Change Approach: make smoking socially unacceptable
56
what are the different stages of preventing violence?
Upfront (primary) prevention where the focus is in taking action before the violence emerges
Thick prevention (secondary) prevention which involves reacting the presence of risk factors for violence
aftermath (tertiary) prevention entails reducing the likelihood of the re-occurrence of violence
57
Define violence
the intentional use of physical force against oneself or another people that either results in injury, death, psychological harm, maldevelopment or deprivation`
58
name 4 evidence based initiatives to prevent violence?
- developing safe and stable relationships between child and their parents
- reducing the availability and harmful use of alcohol
- reducing access to guns, knives and pesticides
- promoting gender equality to prevent violence against women
59
what is an ACE study?
Adverse Childhood Experiences Study
analyses the relationship between multiple categories of childhood maltreatment and health and behavioural outcomes later in life (e.g mental health, chronic disease from alcohol abuse)
60
name 3 challenges and benefits of globalisation?
CHALLENGES
tribal and ethnic tensions may increase and violence may result
already challenges infrastructures struggle to cope
devastating effects on specialist local communities (e.g. coal mining in south wales) and may lead to exploitation
BENEFITS
reduction of poverty
opportunities for education
improvements in health
61
what is globalisation ?
The incorporation of national economies and societies into the world system through movements of goods and services, capital, tech and labour
62
name 3 strategies that address global inequity?
- focus on worse off countries, geographic concentrations and adoptions of multidimensional approaches to development
- the fair redistribution of power, money and resources and the conditions of everyday life
0 changes in the global economic and political context
63
what are the five key points to recognising inflammation/
REDNESS (rubar): dilation of blood vessels
HEAT (calor): peripheral increase in temperature due to hyperaemia
SWELLING (tumor): due mainly to oedema but some contribution from cells
PAIN (dolar): stimunlation of nerve endings by pressure of chemical mediators
LOSS OF FUNCTION
64
conditions of a neurotransmitter?
synthesis
storage
release on demand
post synaptic activity (inactivation)
65
stratified cuboidal
glands
66
simple cuboidal
liver and kidney
67
stratified columnar
urethra
68
what is koilonychias?
a sign of anaemia (spoon shaped nails)
69
when monocyte leave blood to go into tissue they become...
macrophage
70
difference between basophils and mast cells
basophils are mobile
71
type of lymphocytes?
b cells
helper t cells
cytotoxic cells
NUL cells natural killer cell
72
how to macrophages act?
display antigens of pathogen to activate immune response via helper t cells which then activates the b cells to produce antibodies
73
what holds the haem group onto the haemoglobin?
histidine
74
What is autocrine signalling?
A form of cell signalling in which a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on that same cell, leading to changes in the cell
75
order these in order of most reliable to least:
cohort studies
case study
case control studies
systematic reviews and meta-analyse
cross sectional studies
randomised controlled double blind studies
```
systematic reviews and meta-analyse
randomised controlled double blind studies
cohort studies
case control studies
cross sectional studies
case study
```
76
what is a systemic review?
comprehensive literature search that identifies similar similar and relevant studies that satisfy pre-defined inclusion and exclusion criteria.
77
what is meta analysis?
when the results of the individual studies are combined to produce an overall statistic
78
what does the width of the confidence interval tell you about the measurement?
a 95% confidence interval is often interpreted as indicating a range within which we can be 95% certain that the true effect lies
79
how does activation of the voltage gated sodium channel?
the channel is blocked by an activation gate but also has a tail of amino acids present
when the threshold potential is met the activated gate moves out of the way which opens the pore
the rapid influx of sodium channels leads to an increase in resting potential
the globular bundle of amino acids in the inactivation gate tail rapidly blocks the pore of the channel. The sodium channel is only open for a short period of time
this process cannot repeat until the resting membrane potential returns to -70mV. the time in which the process cannot repeat is the refractory period
80
Why does the sodium stop influxing into the membrane during depolarisation?
it reaches the sodium equilibrium potential
81
fertilization occurs after how long?
within 12 hours
82
initiation of cleavage occurs after how long?
within 36 hours
83
layers of the adrenal cortex?
Zona glomerulosa (outer)
Zona fasciculata
Zona reticularis (inner)
84
during the cell replication following fertilization, which stages of the interphase are not carried out?
G1 and G2 since there is no growth and replication of cell organelles
85
what is the zona pellicuda? when does it disappear and what is it replaced by?
the shell around the oocyte. disappears after 3-4 days when the morula enters the uterus. Replaced by trophectoderm and the inner cells become the inner cell mass
86
what is a morula?
solid ball of cells with an inner and outer layer
87
what time does implantation occur?
6-7 days
88
when does the trophoblast divide and into what?
at implantation
| into the syncytiotrophoblast (invasive via metalloproteases) and cytotrophoblast
89
what are the main events of day 8? (hint: implantation)
- trophoblast divides
- two layers form in embryo (epiblast and hypoblast)
- epiblast surrounded the newly developed amniotic cavity
- blastocyst cavity --> primary yolk sac
90
what happens to the hypoblast cells at day 9 (hint: implantation)
the coat the blastocyst cavity to form the primary yolk sac
91
what is the space in the epiblast called?
the amniotic cavity
92
when does the mesoderm begin to form in the trophoblast cells and spaces develop in the sycytiotrophoblast?
day 9
93
what happens at day 12?
spaces form in the extra embryonic mesoderm, chorionic cavity will form by fusion of these
the blastocyst burrows itself into endometrium
syncytiotrophoblast cells erode through the walls of the large maternal capillaries which supply blood into the space ( this is the primate placental circulation)
embryonic disc is bilayers
94
what LA is used in an epidural
bupivacaine
95
what is gastrulation?
the process during which the three primary germ layers form
| it involves cellular rearrangements and cell migrations and marks the beginning of the embryonic period
96
when does gastrulation begin?
DAY 14/15
97
what are the germ layer (top to bottom)
ectoderm
mesoderm
endoderm
98
what controls cell migration and specification?
gene FGF- 8 (fibroblast growth factor) which is involved in pancreatic secretion
99
what aggregates to form the notochord?
the mesoderm under the area that develops into the neural tube
100
what eventually replaces the notochord?
the vertebral column
101
which end of the embryonic disc grows fastest?
the cranial end
102
when does neurulation occur?
the beginning of week 3
103
when change in the ectoderm is induced by the notochord?
it induces it to thicken and form the neural plate
104
where does fusion of the neural folds begin?
the cervical region after which fusion proceeds both cranially (day 25) and caudally (day 27)
105
how does the neural tube form?
the ectoderm thickens to form the neural plate. The neural plate folds inwards to form a groove with prominent lateral folds. Day 22 superior margins of the folds fuse to form the neural tube. anterior part of the tube will form the brain and the rest gives rise to the spinal cord.
106
what do neural crest cells form?
cranial ganglia and glial cells in the CNS
spinal ganglia and neurones
arachnoid and pia mater
schwann cells
107
derivatives of the ectoderm?
nervous system and skin
108
what does the mesoderm divide into?
```
paraxial mesoderm (forms somites)
intermediate mesoderm (forms gonads and kidneys)
lateral mesoderm (forms paired plates)
```
109
derivatives of the mesoderm?
MS system
110
when does the cavity enlarge and sweep around the embryo to fuse and form a cylindrical ambry surrounded by the amniotic cavity
After 28 days
| at this point the body cavity is form and the gut tube is suspended by the mesentery
111
derivatives of the endoderm?
the Gut tube
112
what characterises the foetal period?
the maturation of the tissues and rapid growth of the body
113
what happens when the extracellular [Na+] is high?
creates electrochemical energy due to pressure to diffuse through the membrane
114
what happens when the extracellular [Na+] is high?
creates electrochemical energy due to pressure to diffuse through the membrane
115
Difference between Na symporter and antiporters?
Symporters have a binding site for Na and second molecule to transport them both into the cell using Na electrochemical energy e.g. glucose
Antiporters use Na electrochemical energy to transport calcium and hydrogen ions out of the cell while Na enters
116
What is selective toxicity?
Concept that drugs are intended to be toxic to the invading organisms or cancerous cell but are relatively harmless to the host/normal . This process depends upon the existence of biochemical differences between the target group of cells and the host
117
what are merkel cells?
are the touch receptors in your skins
118
what are Langerhans cell?
antigen presenting cells
119
Where do neutrophils become phagocytes?
in the pulmonary alveoli
120
What do basophils become in the gi lamina proper?
phagocytes
121
give an example of bacterial folate antagonists and how they work as antibiotics?
sulphonamides and trimethoprim
| acts by inhibits the folate pathway in bacteria which is important in cell metabolism
122
example of aminoglycosides and how they work as antibiotics? (hint: mycin)
streptomysin, kanamycin, neomycin and gentamycin
diffuse into the cytoplasm and then binds to the bacterial ribocomes which inhibits protein synthesism which overall LEADS TO MISREADING OF MRNA
123
How do tetrecylcine act?
The prevent attachment of the tRNA to the ACCEPTOR SITE of the mRNA-ribosomal complex which PREVENT AMINO ACIDS FROM BEING ADDED TO THE PEPTIDE CHAIN
124
How does chlorophenicol, erythromycin and clindamysin act as an antiobiotic?
prevents addition of new amino acids to the growing peptide chain at the P SITE hence.
May also prevent TRANSLOCATION of the ribosome down the mRNA template.
125
why is penicillin an ideal drug?
because it cannot be metabolised
126
how do fluoroquinolones act?
inhibit bacterial DNA topoisomerase II also known as DNA gyrase. This enzyme catalyses the introduction of negative supercoil in DNA permitting transcription and replication
