Week 5 Flashcards
1
Q
What is the meaning of Hepatotropic?
A
Ability to infect hepatocytes (liver cells)
2
Q
What are the 2 main facts for comparing Hepatitis Viruses A-E?
A
- All are hepatotropic
2. All belong to different virus families so possess entirely different properties
3
Q
What are the viral features of Hepatitis A (HAV)?
A
- Single-stranded RNA
- Non-enveloped (naked)
- Only 1 serotype
4
Q
What is the transmission of Hepatitis A virus (HAV)?
A
- Feacal-oral
- Poor hand hygiene
- Contaminated food/water (raw shellfish)
5
Q
What are the 6 stages of infection for Hepatitis A virus (HAV)?
A
- Incubation 2-4 weeks
- Virus excreted in faeces 1-2 weeks before symptoms
- GI tract –> Blood
- Infect liver cells
- Biliary tract & back to GI tract
- Excretion in faeces
6
Q
What are the clinical features of Hepatitis A virus (HAV)?
A
- Fever, anorexia
- Nausea, vomiting
- Jaundice
- Dark urine, pale stools
- Liver enlarged
- Spleen palpable in 10%
7
Q
How do you diagnose Hepatitis A virus (HAV)?
A
Presence of anti-HAV IgM
8
Q
What is the prognosis of Hepatitis A virus (HAV)?
A
Excellent in young adults (0.1% mortality)
9
Q
What is the treatment for Hepatitis A virus (HAV)?
A
- No specific treatment
- Comfort & nutritional balance
- Fluid & electrolyte replacement
10
Q
What is the preventative measurements for Hepatitis A virus (HAV)?
A
- Vaccine
- Good hygiene
- Resistant to chlorination
- Killed by boiling for 10mins
11
Q
What are the viral features of Hepatitis B virus (HBV)?
A
- Double-stranded DNA
- Enveloped
12
Q
What are the 3 different Hepatitis B virus (HBV) antigens?
A
- HBsAg- surface antigen
- HBcAg- core antigen
- HBeAg- envelope antigen
13
Q
What is the transmission of Hepatitis B virus (HBV)?
A
- Sexual intercourse
- Intra-uterine, peri- & post-natal infection
- Blood
- Contaminated needles
- Contaminated haemodialysis equipment
14
Q
What are the stages of infection for Hepatitis B virus (HBV)?
A
- Incubation 2-4 months
- 50% develop chronic active hepatitis, 20% of these proceed to cirrhosis, 1-4% risk of these developing liver cancer
15
Q
What is the definition of Icteric?
A
Jaundice
16
Q
How do you discriminate between acute & chronic Hepatitis B virus (HBV) infection?
A
- Both have HBsAg & HBeAg appear during incubation
- In Acute Antibodies to HBeAg & HBsAg appear
- In Chronic there is continued presence of HBsAg & absence of antibodies
17
Q
What are the clinical features of the Pre-icteric period in Hepatitis B virus (HBV)?
A
- Malaise
- Anorexia
- Nausea
- Pain in right upper quadrant (tender liver)
18
Q
What are the 3 possible clinical outcomes of Acute HBV infection?
A
- Fulminant (sudden) hepatitis
- Chronic hepatitis or asymptomatic carrier state
- Resolution
19
Q
What is the treatment for Hepatitis B Virus (HBV)?
A
- Pegylated interferon (α-interferon)
- Nucleoside analogues such as oral lamivudine
20
Q
What are the preventative measurements for Hepatitis B virus (HBV)?
A
- Vaccination (3 injections over 6months)
- HBV immunoglobulin
- Blood screening
- Needle exchange programmes
- Sexual health education
21
Q
What are the viral features of Hepatitis C Virus (HCV)?
A
- 6 virus types
- Single-stranded RNA
- Enveloped
22
Q
What are the clinical features of Hepatitis C virus (HCV)?
A
- Usually asymptomatic
- Fatigue
- Nausea
- Weight loss
- Rarely progress to cirrhosis
23
Q
What may a small proportion of HCV patients develop?
A
Hepatocellular carcinoma
24
Q
What is the transmission of Hepatitis C virus (HCV)?
A
- Blood
- Blood contaminated needles
- Haemodialysis
25
What are the stages of infection for Hepatitis C virus (HCV)?
- Replicates mainly in hepatocytes
| - Incubation 2weeks - 6months
26
What type of screening is available for HCV?
Blood tests based on NAAT
27
What are the different treatments for Hepatitis C virus?
| combination therapy
- Ribavirin + pegylated α-interferon
| - Sofosbuvir (nucleotide analogue)
28
Is there a vaccine for Hepatitis C virus (HCV)?
NO
29
What are the viral features for Hepatitis D virus (HDV)?
- Small circular single-stranded RNA
- Defective
- HDV picks up HBsAg as it buds from liver cell
30
What is the relationship between HDV & HBV?
HBV serves as helper virus for infectious HDV production (co-infection)
31
What is the transmission of Hepatitis D virus (HDV)?
Percutaneously, sexually from infected blood
32
What are the viral features of Hepatitis E virus (HEV)?
- Single-stranded RNA
| - Non-enveloped
33
What is the transmission of Hepatitis E virus (HEV)?
Waterborne disease
34
What is the stages of infection for Hepatitis E virus (HEV)?
- Peak incidence in young adults
- Incubation 3-8weeks
- Self-limiting
35
When is Hepatitis E virus particularly life threatening?
Pregnant women
36
What are the preventative measurements for Hepatitis E virus (HEV)?
- Good sanitation & hygiene
| - Vaccine (Hecolin)
37
What are 6 other causes of Viral Hepatitis?
1. Epstein-Barr virus
2. Cytomegalovirus
3. Yellow fever virus
4. Adenovirus
5. Bunyaviruses
6. Flaviviruses
38
What is the cloaca separated by?
Urorectal septum
39
What does the urorectal septum separate the cloaca into?
- Anterior: urogenital sinus that is continuous with allantois & form the urethra & bladder
- Posteror: rectum & upper anal canal
40
What does lateral folding of the embryo cause?
Close body wall & enclose intra-embryonic coelom (peritoneal cavity)
41
What does the mesoderm form?
Somites adjacent to notochord & developing neural tube
42
What happens to the lateral plate mesoderm?
Cavitates to form coelom
43
What does lateral folding do to the intermediate mesoderm?
Becomes posterior abdominal wall
44
What does the coelom become?
Peritoneal cavity
45
What 4 things are the urinary & reproductive systems derived from?
1. Mesoderm
2. Coelomic epithelium of posterior abdominal wall
3. Endodermally derived cloaca
4. Allantois
46
Where does the Renal Primordia form?
Within the mesoderm of posterior abdominal & pelvic walls
47
What are the 3 types of sequentially developing Renal Primordia?
1. Pronephros
2. Mesonephros
3. Metanephros
48
What does the mesonephric ducts open into?
Cloaca
49
What happens by the 5th week in Urogenital formation?
Ureteric bud extends from mesonephric (Wolffian) duct & induces metanephros that is forming in pelvis & will become the definitive kidney
50
What does the ureteric bud give rise to?
- Ureter
| - Collecting ducts
51
What does the metanephros become?
Renal tissue ie. glomeruli & loops of Henle
52
When is the kidney functional?
10 weeks
53
What happens if the collecting ducts do not meet the nephric vessels?
Cysts form within the kidney
54
What are the 2 possible abnormalities in Kidney formation?
1. Pelvic kidney
| 2. Horseshoe kidney
55
What happens when the ureteric bud branches abnormally before it reaches the metanephric blastema?
Abnormal bifid ureter
56
What happens if the ureteric bud fails to branch at all within the metanephros?
Renal agenesis (failure of growth)
57
What does the urogenital sinus form?
Bladder & urethra
58
What happens to the mesonephric duct once incorporated within urogenital walls?
Move caudally to open into the urethra as vas deferent & ejaculatory ducts
59
What 3 things happen simultaneously in weeks 4 to 6?
1. Cloacal membrane "sinks" into pit of ectoderm
2. Urorectal septum separates cloaca & becomes perineal body
3. Cloacal membrane ruptures leaving anal canal & UG sinus is urethral plate
60
What does the proximal part of the urogenital sinus become?
Bladder
61
What does the allantois form?
Closes to become urachus, which may remain patent
62
What does the pelvic part of the urogenital sinus become?
Prostatic & membranous urethrae
63
How does the paramesonephric duct develop during week 6?
Develops lateral to mesonephric duct as an invagination from a cord of coelomic epithelial cells
64
What does the mesonephric & paramesonephric ducts form?
Reproductive ducts & structures
65
Where are the gonads formed?
Mesoderm of the genital ridge
66
What do germ cells turn into?
Cells that produce ova & sperm
67
What leads to female development from paramesonephric ducts?
Absence of Y chromosome & SRY gene
68
What happens to the mesonephric ducts in the female?
Degenerate due to lack of testosterone
69
What are the Mesonepohric remnants in the female?
- Gartner's cysts near vagina
| - Epoophoron & paroophoron near ovary
70
When does sexual differentiation occur in the foetus?
Week 8
71
What happens to the paramesonephric ducts in the male?
Degenerate but remain as the appendix testis & prostatic utricle
72
What is the appendix epididymis a remnant of?
Proximal end of the mesonephric duct
73
What happens when the 2 paramesonephric ducts in the female lift off the posterior abdominal wall?
Lift peritoneum as the broad ligament
74
What abnormalities can happen in the female reproductive system?
Uterus & vagina may septate & even double
75
What happens to the male gubernaculum during development?
- Shrinks to draw testis down posterior abdominal wall & through inguinal canal with a loop of parietal peritoneum
- Testis should be in scrotum at birth
76
When should the gubernaculum draw the testis through the inguinal canal
8th & 9th months
77
What is the definition of Cryptorchidism?
Failure of complete testicular descent into scrotum
78
What happens to the female gubernaculum during development?
Becomes round ligament
79
What forms the external genitalia?
- Genital tubercle
- Urogenital/Urethral folds
- Labioscrotal folds
80
Describe the development of the male penis?
- Urogenital/Urethral folds form on either side of urethral plate
- Fuse and create urethral groove
- Folds & grooves stop at end of genital tubercle (glans penis)
- Urethral plate continues distally as cord of cells
81
What is glans hypospadias?
Abnormal canalisation of urethra in the glans
82
What is penile hypospadias?
Failure of urethral folds to form, or to extend along the penis & fuse throughout its full length
83
What is common in the urogenital systems & rectum/anal canal?
Connections & fistulae
84
What are the 6 renal functions?
1. Regulation of ECF volume & blood pressure
2. Regulation of osmolality
3. Maintenance of ion balance
4. Regulation of pH
5. Excretion of waste
6. Production of hormones
85
Describe the 2 part structure of a nephron?
1. Glomerulus: network of capillaries
| 2. Bowman's Capsule: double-walled epithelial cup within which the glomerulus is contained
86
What are the 5 step main processes that occur in the nephron?
1. Filtration by glomerulus
2. Obligatory absorption & secretion by proximal tubule
3. Generation of osmotic gradient by loop of Henle
4. Regulated absorption & secretion by distal tubule
5. Regulation of water uptake by collecting ducts
87
What is the triple barrier that glomerular filtration has to occur across?
1. Endothelial lining of capillaries
2. Basement membrane of capillaries
3. Foot processes of epithelial cells (podocytes)
88
What does the triple barrier allow free passage of?
Solutes up to ~60kDa
89
What movement does the triple barrier oppose?
Cells & large proteins
90
What is filtered more in the glomerulus- negatively/positively charged molecules?
Negatively charged molecules filtered less easily than positively charged
91
What forces plasma through the filtration barrier?
Hydrostatic pressure
92
What is R.B.F?
Total amount of blood that transverses renal artery/vein per unit time = 1100ml/min
93
What is R.P.F?
Total amount of plasma that transverses renal artery/vein per unit time
94
How would you work out the R.P.F if the haematocrit is 45% (in a normal adult)?
R.P.F = 55% x 1100 = 600ml/min
95
What affects the production of filtrate?
Balance of pressures (Starling forces)
96
What 2 things FAVOUR movement into tubule?
1. Hydrostatic pressure of blood (+55mmHg)
| 2. Oncotic pressure of the tubule (0mmHg)
97
What 2 things OPPOSE movement into tubule?
1. Hydrostatic pressure of tubule (-15mmHg)
| 2. Oncotic pressure of blood (-30mmHg)
98
What is the normal glomerular filtration rate (GFR)?
125-130ml/min
99
What 2 things can affect the GFR?
1. Larger bodies have larger GFR
| 2. GFR falls with age
100
What are the 3 auto regulation mechanisms of glomerular filtration?
1. Intrinsic/local control
2. Myogenic mechanism
3. Tubuloglomerular feedback (nephrogenic)
101
What is myogenic autoregulation mediated by?
Stretch receptors in the arterioles
102
What does constriction in the afferent arteriole cause?
- Reduces filtration pressure
| - Glomerular filtration rate (GFR) falls
103
What does constriction if the efferent arteriole cause?
- Pressure to back up within the capillary
| - Glomerular filtration rate (GFR) increases
104
What controls GFR?
- Changes to blood flow/pressure
- Afferent arteriole dilation increases GFR
- Efferent arteriole dilation decreases GFR
105
What is the total amount of renal blood flow?
1 - 1.2L/min (20-25% of cardiac output)
106
Does Renal blood flow (RBF) or Glomerular filtration rate (GFR) change when blood pressure changes?
Both essentially constant over wide range of BP
107
How does Tubuloglomerular feedback work?
- Function of juxtamedullary nephron
| - Flow in distal tubule indirectly monitored & high flow information fed back to the arterioles
108
What increases when there is high filtrate flow in the distal tubule?
Na+ & Ca2+ concentrations
109
What does the Macula densa cells, adjacent to the distal tubule, do?
- Monitors Na+ & Ca2+ levels.
- Sends signal to the afferent arteriole causing it to constrict.
- This lowers flow rate to normal limits
110
What 2 types of extrinsic hormonal factors affecting RBF & GFR?
1. Decreased afferent blood flow- VASOCONSTRICTION
| 2. Increased afferent blood flow- VASODILATATION
111
What extrinsic hormones affecting RBF & GFR cause vasoconstriction?
- Sympathetic nerves release norepinephrine
- Circulating epinephrine
- Angiotensin II
112
What extrinsic hormones affecting RBF & GFR cause vasodilatation?
- Renal prostaglandins
| - Atrial natriuretic peptide
113
What countries does Squamous cell cancer commonly occur?
- China
- Iran
- Central Asia
- Siberia
- Mongolia
- Afghanistan
- Iceland
- Finfland
114
What countries does Adenocarcinoma commonly occur?
Western population
115
What can invasive oesophageal candidiasis present with?
Odynophagia, particularly in areas high HIV
116
What else can be a cause of odynophagia in developing countries?
Tuberculosis
117
What are the 3 most common causes of Chronic liver disease?
1. HBV
2. HCV
3. Alcohol
118
What tests should be performed on a patient with history of jaundice?
- LFT
| - Hepatitis B & C serology
119
When should patients with cirrhosis be treated in a specialised centre?
When its complicated by ascites, encephalopathy, bleeding varices or hepatoma
120
What are small-bowel type diarrhoea characteristics?
- Large volume
- Frothy
- Greasy
- Foul-smelling
- Undigested material
121
What are the large-bowel type diarrhoea characteristics?
- >6x per day
- Blood
- Mucus and/or pus
- Tenesmus
122
What are the characteristics of diarrhoea when associated with malabsorption?
- Bulky
- Frothy
- Greasy
- Undigested material
123
What are the adult atypical presentations of coeliacs disease?
- Short statue
- Anaemia
- Metabolic bone disease
- Infertility
124
What can TB & chronic amoebiasis present with?
Constipation alternating with diarrhoea
125
What are the 3 different classifications of Helminths?
1. Nematodes
2. Cestodes
3. Trematodes
126
What 3 places in the body can you find Trematodes infection?
1. Blood
2. Liver
3. Lung
127
What 2 places in the body can you find Nematodes infection?
1. Blood & tissue
| 2. Intestinal
128
What are the 4 different types of host for Helminths infections?
1. Definitive
2. Intermediate
3. Accidental
4. Paratenic
129
Give examples of 4 different vectors & the infections they carry?
1. Flies: Onchoceriasis
2. Aedes mosquito: Filariasis
3. Crysops: Guinea worm
4. Snails: Schistosomiasis
130
What are the 3 different types of transmission for Helminths infection?
1. Faecal oral (Ascaris)
2. Via vector (Filariasis)
3. Direct invasion (Schistosomiasis)
131
Give examples of 6 Helminths infections where inflammation is the main pathogenic mechanism?
1. Filariasis
2. Onchocerciasis
3. Toxocariasis
4. Cysticercosis
5. Schistosomiasis
6. Enterobius
132
What can repeated cycles of inflammation & bacterial infection caused by Filarial lead to?
Acute Lymohoedema --> Elephantiasis
133
What are the clinical features of Trichiuris?
- Vague abdominal symptoms
- Trichiuris dysentery syndrome
- Growth retardation
- Intellectual compromise
134
What are the clinical features of Hookworm?
- Anaemia (adult hookworm takes upto 0.4ml blood)
| - Vague abdominal pain
135
What are the clinical features of Ascaris?
- Vague abdominal pain
- Intestinal obstruction
- Hepatobiliary obstruction & jaundice
136
What can Cysticercosis cause?
CSF obstruction
137
What can cerebral Cysticercosis cause?
Seizures
138
What can 3 things can fibrosis of tissue due to Schistosomes cause?
- Right heart failure
- Portal hypertension
- Bladder cancer
139
What type of treatment is appropriate for helminth infections causing inflammation?
Anti-inflammatory ie. steroids
140
What type of treatment is appropriate for helminth infections causing competition for nutrients?
Reduce worm burden & support nutrition
141
What type of treatment is appropriate for helminth infections causing space occupying lesions?
Surgery, decompression
142
What type of treatment is appropriate for helminth infections causing stimulation of fibrosis?
Helminth eradication & treatment of secondary effects
143
What is the drug treatment for Cestodes?
Praziquantel
144
What should you remember when treating Cysticerosis?
Necessary to continue anti-epileptic drugs & combine anti-helminthic treatment with steroids
145
What is the main drug treatment for Nematodes?
Albendazole
146
What should you remember when treating Nematodes?
Single dose/course of treatment is rarely enough as you must engage with the family & environment
147
What are the mechanisms of action of Praziquantel?
- Not fully known
- Increases calcium permeability of membranes = depolarisation
- May interfere with purine synthesis
148
What 3 specific infections can Praziquantel be used to treat?
- Hydatid disease
- Cysticercosis
- Schistosomiasis
149
What are the possible side effects of Praziquantel?
- Dizziness, headache, drowsiness
- Abdominal cramps & nausea
- Diarrhoea
- Transient asymptomatic rise in transaminases
- Urticaria, rash and pruritis
150
What can Praziquantel interact with?
- Rifampicin
- Carbamazine
- Phenytoin
151
What specific infections can Albendazole be used to treat?
- Nematode infections: trichiuriasis, filariasis
- Protozoa: giardia
- Cestode infections: Neurocysticerosis & hydatid disease
- Other: mebendazole, thiabendazole
152
What are the mechanisms of action of Albendazole?
- Binds to tubules
- This prevents polymerisation into microtubules
- Impaired glucose uptake & depleted glycogen stores
- Degenerative changes appear in worm
153
What are the possible side effects of Albendazole?
- Concentrated in the semen & may be teratogenic
- Persistent sore throat
- Headaches, dizziness & seizures
- Acute liver failure
- Aplastic anaemia & marrow supression
154
What is the mechanism of action of Piperazine?
Agonist activity against the gamma butyric acid receptor paralysing muscular activity
155
What 2 infections is Piperazine used to treat?
- Ascariasis
| - Enterobius infection
156
What are the possible side effects of Piperazine?
- GI tract upset
| - Rarely hypersensitivity, dizziness
157
What 2 infections is Pyrantel used to treat?
- Hookworms
| - Roundworms
158
What is the mechanism of action of Pyrantel?
- Depolarising neuromuscular blockade
- Excreted unchanged in the faeces
- Antagonistic with piperazine
159
What is the mechanism of action of Levamisole?
Nicotinic acetylcholine receptor antagonist
160
What is Levamisole used to treat?
Ascariasis & mixed ascaris hookworm infection
161
What is diethyl carbamazine?
Piperazine derivative
162
What is Ivermectin used to treat?
- Fliarial worms
- Lice
- Scabies
- Bed bugs
- Onchocerciasis
163
What is Niclosamide ONLY used to treat?
Tapeworm infections
164
What are the functions of the Proximal Tubule?
- Recovery of ions, sugars, amino acids, peptides & considerable amount of total water
- Secretes a number of compounds for excretion with urine
- Metabolises some amino acids
165
What are the 2 pathways molecules & ions can take across the tubule epithelium?
1. Transcellular route (cell body)
| 2. Paracellular route (leaky 'tight" junctions between cell bodies)
166
What are the 5 summary points to forces involved in reabsorption from proximal tubule?
1. Ion gradients across the basolateral membrane
2. Sets up an electrochemical gradient of about -3mV (paracellular efflux of cations)
3. Osmotic gradient set up by pumping Na out of the cell into the interstitial space
4. Water moving along the paracellular path due to osmotic pressure drags solutes along with it (solvent drag)
5. Chemical concentration of solutes left behind facilitates a chemical gradient
167
What is the specific ion gradient across the basolateral membrane?
3Na out, 2K in
168
What does the sodium pump (active transport) do in the proximal convoluted tubule cell?
- Na+ concentration gradient
| - Gradient used by cell to transport other substances (secondary active transport)
169
What does co-transport with sodium do?
Moves substances INTO the cell
170
What does counter transport (exchange) with sodium do?
Moves substances OUT of the cell
171
What does the sodium concentration gradient do to H+?
Used as an exchanger to transport H+ OUT of the cell (against its concentration gradient)
172
What are the 4 things that happen on the apical membrane of the giant cell?
1. H+ combines with filtered bicarbonate --> carbonic acid which breaks down to H2O & CO2
2. H2O & CO2 diffuse into the cell
3. H2O & CO2 produce H+ & bicarbonate
4. H+ leaves the cell into tubule lumen
173
What 2 things happen in the basolateral membrane?
1. Chloride, bicarbonate & potassium leave down their concentration gradients
2. Ca2+ is exchanged for Na+. Ca2+ leaves the cell against its concentration gradient
174
What happens to Ca2+ on the apical membrane?
Ca2+ enters through a Ca2+ channel
175
How do other solutes enter the renal proximal tubule?
Coupled to Na+ entry onto apical membrane, facilitated diffusion on the basolateral membrane
176
What is solvent drag?
- Osmotic gradient from lumen to ISF
| - Movement of water (solvent) also "drags" other ions through the paracellular route
177
What is the transport maximum/Tm/Tmax?
- Limit as to how much can be moved
| - mg/min or mmol/min (rate)
178
When can Tmac be exceeded?
Blood concentration is high (glucose in diabetes mellitus)
179
How is the amount filtered calculated?
Amount filtered (mg/min) = Plasma conc. (mg/ml) x GFR (ml/min)
180
What is the reabsorption threshold?
Point at which the amount filtered is equivalent to Tmax
181
What happens when you go above threshold?
- Substance appears in urine when normally 100% is reabsorbed
- Conc of glucose in urine is proportional to plasma conc
182
How much does the Na-glucose transported normally reclaim?
~375mg/min glucose
183
What happens if plasma concentration or GFR increases to reabsorption?
More than normal limits in the tubule, Tmax may be exceeded as reabsorption process cannot cope
184
What makes up the amount of substance appearing in the urine?
Amount filtered + amount secreted
185
What is the movement of Urea in the tubule?
Simple diffusion reabsorbs 50-60% (rest lost)
186
What is the movement of lipid-soluble substances in the tubule?
Simple diffusion
187
What is the movement of phosphate in the tubule?
- Sodium-linked transport
| - Activity of carriers changed by parathyroid hormone
188
What is the movement of protein in the tubule?
Small amount digested to amino acids within the tubule cells
189
What the Clearance of a substance excreted by the kidney?
Volume of plasma which is cleared of the substance per unit time (ml/min)
190
What is the problem with substance clearance?
In reality NO substance is completely cleared during passage through the kidney
191
What are the 3 renal processes which determine & modify the composition of urine?
1. Glomerular filtration
2. Tubular reabsorption
3. Tubular secretion
192
What is the range of clearance?
From zero (filtered then reabsorbed or never filtered) to equivalent of renal plasma flow (all substance filtered by kidney ends up in urine)
193
What is the Filtration Fraction (F.F.)?
GFR (glomerular filtration rate) / RPF (renal plasma flow)
194
What substance has a clearance of zero due to being completely filtered and then reabsorbed?
Glucose
195
What substance has a clearance of zero due to never being filtered?
Protein
196
How do you work out the renal clearance (Cx)?
Cx= Ux x V/Pax
| ```
V= urine flow rate
(U= urine concentration of x)
(Pa= renal arterial plasma concentration)
```
197
What 4 things must a substance be to measure GFR?
1. Freely filtered at glomerulus
2. Neither secreted or absorbed
3. Not metabolised
4. Not toxic
198
What is inulin?
Ideal substance but plant sugar & needs to be infused to establish constant plasma concentrations
199
What does a clearance ratio equal, greater and lesser than 1 tell us about the substance?
- Equal to 1 neither secreted of reabsorbed
- Greater than 1 substance secreted
- Less than 1 substance reabsorbed
200
What are the 3 stages of Alcoholic Liver disease?
Stage 1- Alcoholic fatty liver
Stage 2- Alcoholic hepatitis
Stage 3- Liver cirrhosis
201
Describe Stage 1 Alcoholic fatty liver?
- Build up of fat in liver
- Can occur quickly
- Reversible with abstinence
202
Describe Stage 2 Alcoholic Hepatitis?
- Mild can be reversible
- Major cause of death from liver disease
- Unrelated to infective hepatitis
203
Describe Stage 3 Liver Cirrhosis?
- Significant scarring of the liver
- Generally not reversible
- 50% mortality within 5years if continue to drink
204
What are the different barriers to reducing alcoholic liver disease in Scotland?
- Economic
- Cultural/behavioural
- Political
- Organisational
205
What are the 3 important elements of health promotion?
1. Focus on tackling the determinants of health
2. Working in partnership with a range of agencies & sectors
3. Adopting a strategic approach using a range of complementary actions to promote the health of the population
206
Describe the Ottawa Charter for Health Promotion (WHO 1986)?
- Developing personal skills
- Strengthening community action
- Reorientation health services
- Building healthy public policy
- Creating supportive environments
207
Describe the 3 elements of Tannahill Model of Health promotion?
- Health education
- Prevention
- Health protection/Health policy
208
What is the Population approach in health promotion prevention ?
Aim is to lower the average level of risk factor in the population
209
What is the High-risk approach in health promotion prevention?
People at particularly high risk are identifies through screening, and offered appropriate advice & treatment
210
What is the targeted population approach in health promotion prevention?
Identifying communities at greater risk of disease & using population strategies within these targeted groups
211
When is the population approach useful?
- Disease/risk factor is distributed among large proportions of the population
- Result of not intervening to prevent the disease even in one person are very severe
212
When is the risk approach useful?
- Difficult to change behaviour at population level
| - When there is concentrated risk within the population
213
Whose job is it to reduce Alcoholic Liver disease & Alcohol related harm?
- Scottish government
- Alcohol industry
- NHS
- Retailers
- Police
- All healthcare workers
- Teachers
214
What do oxyntic/ parietal cells secrete?
- HCl
- Pepsinogen
- Intrinsic factor
- Mucus
215
What do pyloric glands secrete?
Mucus to protect pyloric mucosa and gastrin which stimulates ECL cells
216
What does ECL stand for?
Enterochromaffin like cells
217
Where do ECL cells lie?
Deep in oxyntic glands
218
What do ECL cells release & in response to what?
Histamine in response to gastrin
219
What, other than gastrin, stimulates ECL?
Hormones secreted by the enteric nervous system
220
Where is gastrin formed?
Antrum of the stomach
221
Which cells secrete gastrin?
G cells in pyloric glands
222
What food component has a strong effect on gastrin cells?
Proteins
223
What are the 2 polypeptide forms of gastrin?
1. G-34
| 2. G-17 (more abundant)
224
What 5 things stimulate a reverse enterogastric reflex?
- Food in small intestine
- Distention of small bowel
- Acid in upper intestine
- Presence of breakdown products
- Irritation of mucosa
225
What does a reverse Enterogastric reflex do?
Inhibits gastric secretions
226
Which other hormone inhibits gastric secretion?
Secretin
227
How does H. pylori colonise in the stomach?
Uses enzyme urease to turn water into ammonia & neutralise gastric acid, allows them to burrow into mucosal surface
228
How does H. pylori damage the stomach?
- Causes mucosal damage by baterial mucinase
- Inflammation by gastric acids, proteases
- Leukocyte chemotaxis
- Mucosal cell death by cytokines & ammonia
229
What 3 things is H. pylori infection directly associated with?
1. Peptic ulcer disease
2. Gastric carcinoma
3. MALT lymphoma
230
Describe acute infection of H. pylori?
- Nausea, dyspepsia, malise
- ~2 weeks
- Gastric mucosa inflamed with neutrophils & inflammatory cells with marked persistent lymphocyte penetration
- Stomach acid production falls
231
Describe chronic infection of H. pylori?
Local inflammation & gastritis
232
What 5 things does the outcome of chronic H pylori infection depend on?
1. Pattern of inflammation
2. Host response
3. Bacterial virulence
4. Environmental factors
5. Patient age
233
Describe antral-predominant gastritis?
- Inflammation inhibits D-cells & stimulates G-cells resulting in hypergastrinemia
- Gastrin --> acid production causing gastric metaplasia of duodenum
234
Describe Pangastritis?
- Inflammation inhibits D-cells & stimulates G-cells resulting in hypergastrinemia
- Corpus inflammation prevents gastric acid
- Gastric atropy
235
What are the consequences of a Helicobacter infection?
- Peptic ulcer disease
- Distal gastric adenocarcinoma
- Primary gastric MALT
- Dyspepsia
- Atrophic gastritis
- Iron deficiency anaemia
- Idiopathic thrombocytopaenic purpura
236
Describe the urease breath test?
- Patient swallows urea with carbon 13 inside
- Urease is present in the stomach, this is converted to CO2 which is breathed out and detected with C13
- Excess is assumed to be due to H Pylori
237
What are methods of managing peptic ulcer disease?
- Dietary advice
- Antacids
- Bismuth
- Killing H. pylori
- Proton pump inhibitors
- H2 blockers
238
What is the treatment for H pylori?
- Proton pump inhibitor
| - Ampicillin + clarithromycin/metronidazole
239
What should you give to treat H. pylori if patient is allergic to penicillin?
Clarithomycin & Metronidazole
240
How do histamine blocking drugs work?
- Reduce gastric acid by reducing stimulation of oxyntic cells via histamine pathway
- Permits ulcer healing
241
What are the 2 main histamine blocking drugs?
- Cimetidine
| - Ranitidine
242
What are the adverse effects of Cimetidine?
- Dizziness
- Cytochrome P450 inhibitor
- Detoxification of other drugs
- Affects hormone metabolism leading to galactorrhea
- Interferes with tricyclines and serotonin reuptake
243
What are the adverse effects of Ranitidine?
- Malaise
- Dizziness
- Liver toxicity
- Increase risk of GI infection
244
How is Cimetidine & Ranitidine excreted out the body?
Renal excretion
245
Give 1 example of a Proton pump inhibitor used to treat H. pylori?
Omeprazole
246
What are the adverse effects of Omeprazole?
- Headaches
- Dizziness
- Upper respiratory tract infection
- Abdominal pain
- Back pain
- Rash
247
What are the alternative antibiotics you can used for treatment of H. pylori?
Fluoroquinolones
248
How common is failure of the initial course for peptic ulceration?
1 in 5
249
What is the 2nd line of treatment for peptic ulceration?
- Alternative regimen
| - Quadruple (PPI + bismuth + 2 antibiotics)
250
What is Galactorrhae
Breasts produce & leak milk
