anotha one Flashcards
what mode of inheritance is gilberts
autosomal recessive
meaning of penetrance
likelihood of someone with a specific genes to express the phenotype ie me and my brother both have ADHD genes but he actually has ADHD - 50% penetrance
inotropic
contraction of muscles
chronotropic
change in HR
dromotropic
conduction speed
what valves are open/closed in inflow phase
mitral and tricuspid valves are open - blood flows through atria to ventricles
what happens when ventricular pressures exceeds atrial pressure
AV valves snap shut (S1)
what happens in isovolumetric contraction
ventricular systole - contracting of ventricles to raise pressure
no valves are opening
what happens in outflow
pressure in ventricles exceeds aorta/pulmonary artery
so semilunar valves open
isovolumetric relaxation
ventricles relax and pressure in aorta/pul artery exceeds again
no valves open
cardiac myocyte > myofribrils > sarcomeres
what makes up a sarcomere
thick and thin filaments
thick - myosin
thin - 3 types of protein
thin filaments
actin
tropomyosin
troponin complexes - C I T
troponin I
inhibition of actin and myosin binding
by breaking down ATP
troponin T
structural connection to tropomyosin
troponin C
calcium binding site
what results in a contraction
when actin and myosin bind together
what happens when calcium ions binds to troponin C
causes a conformation change in troponin complex and exposes binding sites to myosin can bind to actin > contraction
cardiac action potential duration
200ms - 400ms
elastic arteries
contain more elastin than muscular arteries (which contain external and internal elastic lamina)
what cells are found in crypts of leiberkuhn
enterocytes - absorbe nutrients
enteroendocrine cells - eg I cells secrete CCK
paneth cells - lysosomal enzymes
goblet cells - secrete mucous to promote movement
dendritic cells - mediate food antigen tolerance
peyers’ patches - lymph nodules, low cuboidal M cells
proliferating stem cells - line the wall of crypts
brunners glands - alkaline mucosa - neutralise chyme
what is intrinsic factor
binds to B12
a glycoprotein secreted by parietal cells
pernicious anaemia
IgG
where are peyers patches only found
ileum
how does glucose and galactose enter enterocytes
(SGLT-1) co-transport with sodium - active transport
how does fructose enter enterocytes
GLUT5 - facilitated diffusion
exocrine pancreas secretions receptors
M1/M3 (Ach)
hydrolysis of triglycerides via
pancreatic lipase
absorption of lipids/triglycerides in the small intestine
- trigs need to be emulsified by bile salts
hydrophobic part buries into trig, while hydrophilic part stays sticking out on the membrane - breaking up the trig
- pancreatic lipases (which are water soluble) hydrolyses the trig into a monosaccharide 2 fatty acids
- it becomes a micelle - which can be absorbed by epithelial cells > enterocytes
- golgi/RER/SER make it a trig again, drains into lymph, goes into lacteal and here a chylomicron will come get it and take it into circulation
cranial nerves responsible for saliva release
facial VII and glossopharyngeal IX
dry mouth constipation fluid retention confusion is due to what drug
anticholinergics - Ipratroprium
MoA inhaled corticosteroids
up regulation of anti-inflammatory genes and downregulation of pro-inflammatory genes ie TNFa
MoA ipratropium
bronchodilation - smooth muscle relaxation
what asthmatic tx causes candidiasis
inhaled glucorticoids
MoA montelukast
competes for receptor cytseinyl leukotriene receptor 1 - E4 D4
MoA theophylline
phosphodiesterase inhibitor
what counters the effects of theophylline
activated charcoal
what is the law of la place
smaller sphere > more intense surface tension > greater tendency to collapse
what does surfactant do
reduce alveolar surface tension, reduce collapsing pressure and increase lung compliance
define lung compliance
change in volume that the lungs achieve per unit change in pressure ie emphyema reduces compliance
dorsal respiratory group
frequency of inspiration
basic rhythm of inspiration
apneuistic centre
sleep breathing
respiratory control centres
medulla and pons
medullary resp centre :
dorsal - inspiratory
ventral - expiratory
DIVE
pneumotaxic centre
inhibits respiration / resets
cerebral cortex
allows for voluntary breathing ie hyperventilating
what is the forced vital capacity
air that can be maximally expired after a maximal inhalation
type 2 chronic resp. failure oxygen goal
88-92%
what do central chemoreceptors respond to
H+ ions - acidic
Fick’s Law of diffusion
rate of diffusion = (alveolar area x diffusion constant x difference in partial pressure) / thickness of alveolar membrane
what would increase rate of diffusion of gas from alveoli to blood
thick alveolar membrane
where are S cells located
jejunum and duodenum
function of S cells
secrete secretin which is aq bicarbonate - neutralises stomach acid ie is responsive to low pH in the duodenum
D cell secretion
somatostatin
I cell secretion
CCK
what cells does omeprazole work on
parietal cells
secrete HCl acid via H+/K+ ATPase pump
chief cells
secrete proteases - pepsinogen and chymosin
breaks down proteins
enterochromaffin cells
histamine - histamine promotes acid secretion
G cells
secrete gastrin
what does enterokinase do ?
trypsinogen > trypsin
enterogastric reflex
signal = chyme in the SMALL intestine - inhibits gastric secretion
MoA orlistat
-inhibits the hydrolysis of triglycerides - a pancreatic lipase inhibitor
therefore can cause steatorrhea
weight loss medication
what are the 3 gastric glands
cardiac - cardia
pyloric - pylorus
and gastric - fundus
which 2 gastric glands are histologically the same
gastric and pyloric - contain mostly surface mucous cells
gastric glands
contain :
parietal cells chief cells mucous neck cells enteroendocrine cells stem cells
what are gastric pits
invaginations in the gastric surface epithelium , they connect to gastric glands and allow glandular products to be secreted
when is exocrine pancreas secretion at its highest
intestinal phase e
MoA metaclopramide
dopamine antagonist
promotes gastric emptying - relaxation of the LOS
stops nausea and vomitting - is a anti-semitic
pressure gradient that drives pulmonary blood flow in upright lung base
arterial pressure is greater than venous pressure
primary vasoactive substance that regulates pulmonary vascular resistance
oxygen
perfusion pressure in zone 1 lung
PA > Pa > Pv
results in alveolar dead space as alveolar pressure exerts itself on the capillaries - compressing them - reducing blood flow
*dead space = alveoli are ventilate but not perfused
perfusion in lung zone 2
Pa > PA > Pv
Pa is greater here due to the effects of gravity - Pa > PA drives pulmonary blood flow
lung bases - zone 3
Pa > Pv > PA
highest pulmonary blood flow here
is lobar pneumonia a type 1 resp failure
yes
pathophysiology of chronic bronchitis
chronic exposure to smoke or air pollutants leading to mucus hyper secretion in the bronchi
pathophysiology of interstitial lung disease
irreversible scarring of pulmonary connective tissue due to chronic inflammation
abnormal irreversible enlargement of the alveoli due to alveolar wall destruction
emphysema
most common bacteria - community acquired
streptococcus pneumonia
nerve damaged most likely to cause respiratory failure
phrenic nerve
guillane barre syndrome
autoimmune neuropathy
glycopeptides
eg = vancomycin, bleomycin
bacterial cell wall - mode of action
sulphonamide + trimethoprim
co - trimoxazole
via folate
penicillin MoA
inhibits peptidoglycan cell wall by preventing the cross-linking by binding to transpeptidase
protein synthesis antibiotics
tetracycline - these ones form complexes with other ions
aminoglycosides
macrolides
cephalosporins
ie ceftriaxone
works well against gram - bacteria
can pass the blood brain barrier
fluoroquinolone
eg ciprofloxacin
inhibits the p450 liver enzymes
they inhibits DNA gyrase - bactericidal
amino glycoside
ie gentamicin
can cause ototoxicity
protein synthesis inhibitor
treatment of TB
RIPE
rifampicin - orange wee
Isoniazide
Pyrazinamide
Ethambutol
2 months of RIPE
4 months of RI
mantoux test +
TB
widespread downsloping ST segments can be caused by what drug
digoxin
sinus bradycardia 1stTx
IV atropine
beck’s triad
pericardial tamponade :
muffled heart sounds
low bp
Raised JVP
what is beck’s triad associated with
cardiac tamponade
how to treat cardiac tamponade
pericardiocentesis if haem. unstable
Tx acute pericarditis
NSAIDS + colchicine
- corticosteroids
- abx / pericardiocentesis
atrial flutter
P waves irregularly irregular
sawtooth / flutter baseline
homelessness
TB
infective endocarditis signs + main inv
tricuspid valve splinter haemorrhage staph. aureus , strep viridans poor dentition osler nodes janeway lesions roth spots
3 cultures at 3 different times/sites > then trans thoracic echo
what hepatitis has a high associated with hepatocellular cancer
B
must screen using alpha-fetoprotein
carcinoid syndrome
carcinoid tumour broken down systemically into circulation causing flushing and wheeze as a GI symptom
urinary 51AA - investigation
campylobacter jejuni
Guillaine Barre
Milk
wilsons
caeruloplasmin
haemochromatosis
ferritin
acute/severe UC tx
IV corticosteroids
erythema nodosum
mainly crohns
beading of bile ducts / onion skinning
primary sclerosis cholangitis
infections that seem like IBDs
whippleis
giardiasis
bacterial overgrowth
> > would need to do a stool microscopy
65-year-old lady who has recently been diagnosed with polycythaemia rubra vera, is admitted to the Emergency Department with sudden onset abdominal pain and swelling. On examination, she had a tender, palpable liver, with moderate abdominal distension and shifting dullness. What is the most likely diagnosis?
budd chiara - hepatic vein thrombosis
tx for watery diarrhoea + shigella
ciprofloxacin + iv fluids
if curb65 <2
manage patient at home with antibiotics for 7days
and sort appointment soon
swinging fever
empyema
chlamydophila psitacci
bird - pneumonia
pulmonary fibrosis investigation
high-resolution CT
what type of pneumonia would show hyponatreamia
legionella
TB - where ?
geographically - india most common
anatomically - upper/middle lungs
BNP +
pulmonary hypertension
type 2 resp. failure when:
PCO2 >6 PO2 <8
how do we manage
non-invasive ventilation
type of pleural effusion likely due to HF
transudate
ie protein <25g/L
protein 35g/L
indicates infection
gram negative coccobacilli associated with COPD
haemophilus influenza
hospital acquired bacteria (most common ones)
pseudomonas aerginosa
staph aureus
enteroabacteria
klebsiella
red currant jelly
alcoholics
mycoplasma pneumonia
joint pain-y pneumonia
younger patients
pneumocystis pneumonia
HIV
