TAS Book Flashcards
(213 cards)
1
Q
Contraction of what structure in the eye determines pupillary size
A
The iris
2
Q
Sphincter pupillae in the eye are under what autonomic control, and what receptors do they act through?
A
Parasympathetic control to constrict the pupi
Under M3-muscarinic acetylcholine receptors
3
Q
Dilator pupillae in the eye are under what autonomic control and what receptor do they act through?
A
Sympathetic control to dilate the eye
Act via alpha-1 adrenoceptors
4
Q
MOA pilocarpine
A
Non-selective muscarinic receptor AGONIST
To contract the iris and ciliary muscle
5
Q
MOA ipratropium bromide
A
Non selective muscarinic antagonist
6
Q
MOA mag sulf
A
Histamine release blocker
7
Q
MOA montelukast
A
LTRA (blocks D4)
8
Q
MOA theophylline
A
PDE inhibitor
9
Q
How do B2 receptors act
A
Through activation of adenyly cyclise and increase intracellular cyclic AMP > relaxation of constricted bronchial smooth muscle N.B no effect on inflammation
10
Q
What qualifies as a positive response in a bronchodilator test
A
9% or greater difference
11
Q
Criteria for peak flow to be considered valid
A
If 3 attempts are within 10% of each other
12
Q
Inheritance of primary ciliary dyskinesia
A
AR
13
Q
During embryology, what is normal cilia required for?
A
To determine the laterality of the heart and abdominal organs
14
Q
Ix to diagnose primary ciliary dyskinesia
A
LOW exhaled nasal nitric oxide
15
Q
What keeps the ductus arteriosus patent
A
Low oxygen tension in the blood
Dilating effect of PGE-2 by the placenta
16
Q
x and y axis of oxygen dissociation curve
A
X axis - PO2
Y axis - Hb saturation
17
Q
Left shift of the O2 dissociation curve - what does this mean
A
INCREASED affinity for O2, so REDUCED offloading of oxygen to the tissues
18
Q
Right shift of the oxygen dissociation curve - what does this mean
A
REDUCED AFFINITY for oxygen, so INCREASED OFFLOADING to the tissues
19
Q
Functional closure of the ductus arteriosus is facilitated by?
A
prostaglandin loss from the placenta
20
Q
Pathophysiology of Eisenmenger syndrome in VSD
A
The pulmonary arterial pressure increases to equalise the systemic pressure, so the shunt becomes bidirectional
21
Q
Where is the 1st HS best heard
A
The apex
22
Q
Where is the 2nd HS best heard
A
Sides of the upper sternal edge
23
Q
Breathing affects the closure of which valves ? And how?
A
The aortic and pulmonary valves, therefore character of the 2nd HS changes
Inspiration > decreased intrathoracic pressure > pulls blood from body into vena cava > increased R venous return > blood stays in the lungs because of the surrounding vacuum > reduced filling of L side > delayed closure of pulmonary valve relative to aortic valve
24
Q
Why is there a split second HS in an ASD
A
The defective septum means that there is a continual increase in right atrial filling
25
Characterisation of the 2nd HS in pulmonary HTN and why
It is louder
Because the pulmonary valve ‘slams’ shut
26
When is an ejection click heard
In early systole from a stenoses aortic or pulmonary valve
27
Inferior leads
Anterior leads
Lateral leads
Inferior - II, II, aVF
Anterior - V1-V4
Lateral - I, aVL, V5, V6
28
Normal cardiac axis
-30 to +90
29
QT interval
From beginning of Q wave to end of T wave
30
Gazettes formula
QTc.= QT / square root of RR
31
Ventricular repolarisation involves the outward flow of which electrolyte
potassium - any delay in potassium extrusion prolongs the QT interval
32
LQT1 gene defect
KCNQ1
33
LQT2 gene defect
KCNH2
34
LQT3 gene defect
SCN5A
35
Diabetic infants are at 10x higher risk of what type of abnormalities
Cardiac abnormalities
1 - cardiomegaly
2- asymmetry of the ventricular septum
36
Most common cardiac abnormality in congenital rubella
PDA
37
Presentation congenital rubella
Deafness
Cardiac - PDA
Cataracts, retinopathy, iris hypoplasia
Microcephaly
Speech and language delay
38
Congenital varicella presentation
Skin scarring
Digit dysplasia
39
Congenital CMV presentation
Hepatosplenomegaly
Petechiae
Jaundice
Sensorineural HL
40
Congenital toxoplasmosis presentation
Chorioretinitis
Cerebral calcification
hydrocephalus
41
Alprostadil works on … ?
PGE 1
42
Dinoprostone works on … P
PGE2
43
How are epithelial cells bound to the basement membrane of the skin
By hemidesmosomes, or to surrounding cells by desmosomes
44
What is a desmosome
A transmembrane protein attached to the cytoskeleton of their cell and linked to the desmosome of the adjacent cell
45
In SSSS, what is there breakdown of ?
Desmosomes
46
What is the main constituent of the cytoskeleton in the stratum corneum?
Keratin
47
Natural moisturising factors in the skin
Filaggrin
48
What causes ichythosis vulgaris
Loss of function mutation in the filaggrin gene
49
Layer of skin affected in dystrophic epidermolysis bullosa
Dermis
50
Layer of skin affected in epidermolysis bullosa simplex
Basal cell layer
51
Layer of skin affected by pemphigus vulgaris
Prickle cell layer (2x P’s)
52
Layer of skin affected in SSSS
Stratum granulosum
53
Layer of skin affected in TENS
Dermis epidermal junction
54
Type A staphylococcal toxins go on to cause … ?
Bullous impetigo
55
Type B staphylococcal toxins go on to cause … ?
SSSS
56
Why do scalds travel more rapidly into tissue than flame burns?
Because wet heat conducts 100x more efficiently than air
57
Temperature that cellular skin damage occurs
> 49 C
58
‘Superficial’ burn definition
Outer epidermal layer affected
59
Definition of a ‘partial thickness’ burn
SUPERFICIAL =
Entire epidermis and up to 1/3rd of upper dermis (BLISTERS)
DEEP =
Entire dermis and most of the dermis (NO BLISTERS)
60
Full thickness burn definition
All of the epidermis and dermis affected (PAINLESS)
61
‘Zone 1’ definition in thermal injury
Zone of hyperaemia
= area of superficial injury, warm and red
62
‘Zone 2’ definition in thermal injury
= zone of stasis
There is damage to the microcirculation which changes to micro vascular permeability
63
‘Zone 3’ in thermal injury
Zone of coagulation
= heat damaged cells occlude blood vessels
64
Year that the ‘battered child’ was first described
1950s
65
Most common form of intentional burn
Scalds
66
Most common form of growth hormone deficiency
Idiopathic isolated GHD
67
Does GH affect intrauterine growth ?
No - so early infancy growth is often normal
68
GH is release in what type of fashion
Pulsation
69
GH is stimulated by … ?
Time of the day when it is max secreted
GHRH
Early part of the night
70
GH is inhibited by … ?
Somatostatin
71
Gold standard Ix to investigate GHD in > 5 year olds
Insulin tolerance test
72
GH causes increased production of what substance ?
IGF-1
Which then exerts its biological effect at bone, liver, fat and muscle
Therefore GHD presents with reduced muscle bulk and increased subcut fat
73
Mid parental height calculation
Dads height + mum’s height divide by 2
Then after 7cm for boys and take 7cm for girls
74
inheritance of marfans
AD
75
Constitutional tall stature typical presentation
Often normal birthweight, accelerated growth in infancy
76
tall stature with developmental delay - causes ?
Homocystinuria
Klinefelter’s
77
Long legs and short back - differentials?
Marfans
Klinefelter’s
78
What is the tall stature seen in aneuploidy (e.g. Klinefelter’s) thought to be due to
Short stature home box gene (SHOX) - located on the X and Y chromosomes
79
X-rays used to determine skeletal maturation
L hand and wrist X-rays
80
Negative feedback loop for cortisol secretion
CRH (hypothalamus) > ACTH (pituitary) > cortisol (adrenal gland)
81
Exogenous cortisol use - what effect does this have on the feedback loop
Causes a negative feedback on the secretion of CRH and ACTH
82
Why is it better to give steroids in the morning
Evening doses tend to suppress the normal early morning ACTH surge so can increase chances of adrenal suppression
83
Cortisol exhibits what form of release pattern?
Diurnal
84
In SST test - what dose of ACTH is given
Compared to normal secretion dose
250 mcg
Normally secrete 1 mcg
85
ACTH secretion exhibits what type of rleease pattern
Circadian
86
Inheritance of CAH
AR
87
Most common type of CAH
Deficiency in 21-hydroxylase
88
Presentation CAH with regards to Na, glucose and K
Hypoglycaemia - because there is no cortisol
Hyponatraemia and Hyperkalaemia - due to associated deficiency of aldosterone
89
When is the best time to test for 17-OHP
After 72h of life
90
Barnet-Biedl syndrome inheritance
AR
91
Barnet-Biedl presentation
Early childhood obesity
92
How does leptin deficiency present
With massive early obesity (from birth)
93
Where does majority of water absorption in the gut occur
Jejunum
94
Role of diffuse neur-endocrine hormones in the gut
Act to reduce transit time e.g. peptide YY
95
Where does reabsorption of bile acids occur
Ileum
96
Does secretly diarrhoea continue even when not eating
Yes
97
Role of the ileum
Reabsorption of B12 and bile acid
98
Substance release by parietal cells
intrinsic factor
99
Describe normal absorption of B12
Binds to R-proteins in the stomach to avoid degradation by stomach acid
R proteins are digested by proteases in the duodenum and B12 is released
B12 then combines with intrinsic factor which is absorbed in the terminal ileum
100
How do bile salts aid fat absorption
They encase fatty acids, cholesterol and fat soluble vitamins in the duodenum and form MICELLES
The lipid content of the micelles are absorbed at the cell membrane and the bile salts stay in the lumen and then are transported back to liver
101
Consequence of ileal resection with regards to fat absorption
Can’t absorb fat and fat soluble vitamins as well so get high levels of intraluminal fat
The fat then binds to calcium and prevents it from binding with dietary oxalate
High levels of oxalate cause fatty stools and renal oxalate stones
102
Vitamin A deficiency presentation
Night blindness
103
Vitamin D deficiency presentation
Rickets, bone pain
104
Vitamin E deficiency presentation
Neuroaxonal degeneration / retinopathy
105
Vitamin K deficiency presentation
Deranged coag
106
Osmotic diarrhoea definition
Occurs due to damaged intestinal mucosa syndrome so can’t absorb osmotically active nutrients
O the osmotic gradient that is created draws water into the intestine
107
Secretory diarrheoa definiton
Intestinal epithelial cells are actively secreting ions and water into the bowel lumen
108
Motility diarrhoea definition
Reduction in the amount of time luminal contents have in contact with the bowel
109
Where is lactase produced
Exclusively in the enterocytes of the small intestine, predominantly the brush border
110
‘Dark brown pigmentation of the colonic mucosa’ on colonoscopy - suggests what cause?
Laxative abuse
The brown pigment is lipofuscin
111
Breakdown of haem into bilirubin occurs by which system
The reticuloendothelial system
112
RBC is broken down into …
HAEM >>> Fe / CO / biliverdin > bilirubin (unconjugated)
And
GLOBIN >>>> amino acids
113
How is unconjugated bilirubin carried in the circulation
Bound to albumin, which prevents it from diffusing into urine or peripheral tissues
114
Where does bilirubin conjugation occur and how
In the liver by the enzyme UDP glucoronyltransferase
115
What drug is known to induce UDP glucoronyltransferase
Phenobarbitone
116
Once bilirubin has been conjugated in the liver where does it travel
The bile ducts and then to the gut
117
What happens to conjugated bilirubin in the gut
1. Hydrolysed by gut bacteria
> urobilinogen
> oxidised by intestinal bacteria
> makes stercobilin (causes brown stool)
2. Oxidised back to biliverdin (characteristic green colour)
118
Genomic imprinting definition
How the phenotypic expression of a gene depends on the parent of origin
119
Gestation that the fetal urethra is patent by
8 weeks
120
What predominately influences amniotic fluid volume in the early stages of pregnancy
Fetal size - fluid passes freely across the permeable surface membranes of the fetus before skin keratinisation occurs at 19w
121
Hydronephrosis definition
Abnormal dilatation of the renal pelvis +/- dilatation of the calyces
122
Definition of PUV
Membranous partial obstruction of the posterior urethra
123
Describe the process of the 1st meiotic definition
Each cell replicates its DNA - ie 46 ‘double chromosomes’
These chromosomes pair up and form a line between them - chiasm (allows exchange of information and genetic variability)
Each pair pulls apart and moves to the opposite ends of the cell - each cell contains 23 ‘double chromosomes’
124
Describe the 2nd meiotic division
Each of the ‘double chromosomes’ split, with each half moving to opposite ends of the cell which then divide to leave each germ cell with 23 chromosomes
125
‘Non-disjunction’ definition
A paired Chromsome fails to separate during the first meiotic division
When division occurs one cell has 2 copies and the other has none
Then at fertilisation there is 3 copies of that chromosome
126
Most common cause of trisomy 21
Maternal non disjunction (88%)
127
Definition of mosaicism
When non disjunction occurs during mitosis rather than meiosis
128
Described the ‘combined test’ for downs
USS and blood test (PAPP-A and b-HCG)
129
Describe the quadruple test for downs
AFP
b-HCG
Inhibin
Oestriol
130
Gestation for CVS
10-13w (1% miscarriage risk)
131
Gestation for amnio
16-20w (1% risk of miscarriage)
132
Inheritance G6PD
X linked recessive
133
Inheritance haemophilia A and B
X linked recessive
134
Bone marrow failure .. retics up or down?
Down
135
Premature red cell destruction … retics up or down?
Up
136
Most common defect in hermit dairy spherocytosis
Spectrin
137
Mutation in sickle cell
Single mutation in the beta globin chain which substitutes valine for glutamic acid (v to g0
138
Best established genetic modifiers of sickle cell severity
Fetal Hb concentration
Co-inheritance of alpha-thal
139
Effect of co-existence of alpha thal trait in sickle cell
Reduced concentration of Hb in erythrocytes, so there is reduced tendency of HbS to polymerise, resulting in increased Hb and reduced rate of haemolysis
140
Factors increasing the risk of painful crisis in sickle cell
Higher Hct
Lower Fetal Hb
141
Pathophysiology in DIC
Unregulated activation of the clotting pathway leading to excess fibrin clots
142
Presentation of ITP
Multiple bruises, otherwise healthy, history of recent viral illness
143
Pathophysiology of ITP
Splenic destruction of antibody coated platelets
144
Chromsome in vWD
Chromsome 12 (AD inheritance)
145
How are vWF and factor VIII linked
VWF is a carrier protein for factor VIII, protecting it from degradation
146
Incubation period of varicella
10-21 days
147
VZV - type of virus?
DNA virus
148
Most abundant immunoglobulin
IgG
149
Main immunoglobulin of acquired immunity
IgG
150
First antibody produced in response to antigen exposure
IgM
151
immunoglobulin responsible for mucosal immunity
IgA
152
Role of IgD
Membrane immunoglobulin, has a role in signalling activation of B cells
153
Only Ab to cross placenta
IgG
154
When does most placental transport of IgG occur
In the 3rd trimester, so prem babies much higher risk of infection
155
When are neonates most at risk of neonatal varicella infection
If mum developers infection 5 days prior to 2 days after delivery
156
Site of 25-hydroxylation of vitamin D
Liver
157
Biologically active form of Vitamin D
Calcitriol
158
What is the main cause of cardiac arrhythmia in hypocalcaemia
QT prolongation
159
Skin abnormality seen in hypocalcaemia
Petechiae - Ca is required for platelet function
160
Most common form of inheritance of inherited hypo phosphataemia
X-linked
161
Urine abnormality associated with hypophosphataemic rickets
Glycosuria
162
Explain process of vitamin D synthesis
Cholesterol
> exposure to UV light
Cholecalciferol
> hydroxylation by 25-alpha hydroxylase (in the LIVER)
25-hydro y vitamin D (calcidiol)
> converted by 1-alpha hydroxylase (in the KIDNEY)
1,25-dihydroxyvitamin D (calcitriol - active form)
163
Roles of active vitamin D
- promote ca absorption in the small intestine
- promote bone resorption via osteoclast regulation
- allows parathyroid gland to regulate Ca and phosphate homeostasis via PTH production
164
Inheritance OTC deficiency
X linked recessive
165
Pathophysiology of organic acidaemias
E.g. propionic acidaemia
Inhibit production of N-acetylglutamate
166
Presentation NAGS
Severe and presents in the neonatal period
167
Classic Q for OTC deficiency
“Girl with previous gastro illnesses requiring IV rehydration”
168
Pathophysiology of spinal muscular atrophy
Progressive degeneration of the alpha motor neuron from anterior horn cells in the spinal cord
169
How many neurons are sensory pathways composed of
3
170
Role of tertiary neurons in sensory pathways
Carry impulses from the thalamus to the primary somatosensory area of the cerebral cortex on the POST central gyrus
171
Where do spinothalamic neurons cross over
Just above entry point
172
Where does dorsal column sensory info cross over
In the medulla
173
Where do motor neurons cross over
In the medulla
174
Location of cell bodies of LMN
In the anterior horn of the spinal cord
175
Presentation brown-square hemisection
Contralateral loss of pain and temp
Ipsilateral loss of fine touch and proprioception
Ipsilateral paralysis
176
Role of acetozolamide in IIH
Aims to rescued production of CSF
177
Best predictor of the degree of heart failure in VSD
Pulmonary : aortic flow ratio
178
Echo changes seen in a moderate VSD
Dilation of the left atrium and ventricle (because of the increased return to the left ventricle)
179
Best indicator for early corrective surgery in VSD
Aortic valve regurgitation
180
What does the magnitude of the shunt depend on in VSD
1. The size of the defect
2. Pulmonary vascular resistance
181
Effect of grunting on functional residual capacity
Increases FRC
182
Effect of grunting on critical closing volume
Reduces it
183
Factors influencing the FRC in a baby
Elastic recoil of the chest
Time allowed for expiration
The expiratory flow rate
184
Effect of surfactant on the critical closing volume
Reduces it
185
Number of alveoli at 32 weeks
Nearly 0
186
What is co2 clearance determined by
The minute volume MV = RR x TV
187
What is oxygenation determined by
The mean airway pressure (MAP) = inspiraotry time x PIP + expiratory time + PEEP
188
Role of humidified incubators
Reduces insensible transepidermal water loss
189
Presentation in SIADH
Fluid overloaded with low urine output
Rx fluid restrict
190
Serum osmolality and urine osmolality in SIADH
Serum - low
Urine - high
191
Serum and urine osmolality in cerebral salt wasting
Serum - low
Urine - very high
192
Serum and urine osmolality in central DI
Serum - high
Urine - low
193
Serum and urine osmolality in dehydration
Serum - high
Urine - low
194
Ultrafiltration at bowman’s capsule i dependent on what 3 factors
Renal blood flow
Hydrostatic pressure
Oncotic pressure of plasma
195
Charge of the glomerular basement membrane
Negatively charged
196
Where in the kidneys is most Na reabsorbed
PCT
197
MOA ADH
Acts on the aqua-porin 2 water channel to increase collecting duct permeability
198
Gas abnormality in loop diuretics and why
Metabolic alkalosis
In response to low K there is reabsorption of K with secretion of hydrogen ions, (the reabsorption of K isn’t enough to prevent hypokalaemia)
199
Site of action of thiazide diuretics
DCT
Inhibitor Na and Cl reabsorption
200
MOA mannitol
Alters the osmotic pressure in the renal tubule because it is freely filtered at bowman’s capsule
201
Indications for renal biopsy in nephritis
Creative remains abnormal at 6 weeks
Low c3 > 3 months
Proteinuria persisting > 6 months
202
MOA midazolam
GABA agonist
203
Ethosuxamide MOA
Calcium channel blocker
204
How to diagnose lactose intolerance
Removal and retintroduction of lactose in diet and do hydrogen breath test
205
1st line Rx for CMPA
Extensively hydrolysed formula
206
Main protein constituents of infant milk
Whey and casein
207
Main carbohydrate source in infant milk
Lactose
208
In brain stem death - what CN do pupillary reflexes test
II and III
209
Corneal reflex tests what CN
V and VII
210
Vestibule-clear reflex tests what CNS
III, IV, VI, VIII
211
Supraorbital pressure tests what CNs
VII, XI, XII
212
Gag reflex tests what CNs
IX and X
213
Main method of pcm inactivation in neonates
Sulphonation
