Cardio Week 7 Flashcards
Why is the subendocardium the most susceptible to MI?
That area is subject to the greatest pressure during systole hence has the most restricted blood flow.
How can you increase O2 supply to the heart?
Dilate coronary arteries - atherosclerotic arteries may be dilated maximally already
Decrease HR - increases the time of diastolic coronary a. blood flow
What occurs in Type I error (alpha)?
The study shows an effect when in reality there is none.
The major burden of pathology in Australia is from which genetic disease?
CF
Are genetic and congenital diseases the same?
No, congenital diseases are just those apparent at birth; not all congenital diseases are genetic (eg thalidomide poisoning)
What is contained in mast cell’s preformed granules?
Histamine, heparin, tryptase, chymase and TNF-alpha
Which coronary generally supplies the SA and AV nodes?
The right coronary artery
At what level is vomitus likely to drain into?
Apical segment of the lower lobe of the right lung - because it has the shortest distance from the trachea.
What is ApoB-100
Protein that is the mechanism for recognition of lipoprotein in the liver. Expressed on LDL
What factor in a study determines its power?
Sample size
What is the name of the sleeve of pleura that hangs down below the hilum and what does it allow for?
The pulmonary ligament. It allows room for veins to expand into if they overfil with blood
Define allergy?
Immune mediated response to environmental antigen that are otherwise harmless
What is special about the Fc(epsilon)R?
- On mast cells and binds IgE
- Only FcR that can bind antibody that isn’t already bound to ag
What are the 3 fates of cholesterol that is synthesised in the liver?
- Ester formation - made into VLDL for export
- For production of bile acids that are used to emulsify fatty meals
- Membranes
Is it possible to see bronchial arteries and veins?
Generally no but it is possible to see lymph nodes sometimes due the carbon pigment.
What are the possible side effects of statins?
Depletion of Q10 causing skeletal and cardiac muscle complications
How can you tell the right lung?
It has three lobes and therefore 2 fissures. The imprints of the great veins may be seen.
How can you tell the left lung?
2 Lobes, 1 Fissure. Clearly defined indentation of the aorta and heart. Cardiac notch present.
What is the general shape of a segment of the lung?
Pyramid with the apex pointing towards the hilum and the base on the surface of the lung
What are names of the three lobes of the right lung?
Upper, middle and inferior
What is the name of the gene that is mutated in CF? On which chromosome does it lie?
CFTR: Cytic fibrosis transmembrane conductance regulator
Chromosome 7.
What is the normal function of HDL?
HDL is a cholesterol scavenger that take cholesterol back to the liver for production of bile salts. It also acts on macrophages to stop them becoming foam cells.
In terms of antigens, what is special about delayed type hypersensitivity?
Antigens are persistent in delayed type - this causes an accumulation of T cells and macrophages attempting to clear it.
eg. TB
What are 4 mechanisms of antibiotic antagonism?
- Bacteriostatic antibiotics that stop bacteriocidals working eg tetracycline (static) stops penicillin (requires bac to be growing to kill)
- Induction of enzymes eg amoxycillin is a good inducer of betalactams while pippercillin isn’t therefore they are not good together
- Competitive binding for the same target
- Inhibition of target
Where is the pulmonary artery in relation to the bronchus in the right lung?
Anterior
What is mendel’s second law?
Different genes are inherited differently, unless they are on the same chromosome.
What is Marfans syndrome characterised by?
Bone overgrowth and joint laxity, increases susceptibility to aortic dissection.
Mutation in fibrillin 1 gene
What is Der p 1?
Allergen from house mites - the mite faeces
What occurs in type 2 error (beta)
Study shows no treatment effect when in reality there is one.
Why is the left lung smaller than the right?
Its development is impeded by the heart
What are the names of the fissures of the right lung? What which lobes does they separate?
Oblique - the inferior from the middle and upper
Horizontal - the middle and the upper
At what level does the trachea bifurcate?
T4/5
Where does the apex of each lung sit?
Tightly in the concavity of the 1st rib.
What are some non atherosclerotic related causes of coronary a. occlusion in MI?
Ventricular thrombus
Inflammation/vasculitis
Aortic dissection
Which areas of the heart does the left anterior descending coronary artery supply?
The LV, RV and 2/3 of the intraventricular septum
What are the 3 types of dyslipidaemias
Hypercholesterolaemia
Hypertriglyceridaemia
Mixed Hyperlipidaemia
What are some problems with bile acid sequestrants/resins?
- bloating, constapation
- decreased absorption of other drugs
What is the mechanism of nicotinic acid / niacin to lower LDL?
Mechanism unknown
Decreases VLDL secretion from the liver
Decrease plasma LDL and triglyceride
Increases HDL
Usually used in combination
How is a greater O2 demand in the heart met?
Can only be done by increasing blood flow (by dilation of coronary vessels) as the maximum O2 is already removed from blood.
What are the charactistic immunogical features of an atopic individual?
- Elevated IgE
- High numbers of eosinophils
- large numbers of IL-4 secreting Th2 cells.
What are the vessel level consequences of atherosclerosis?
- Vessel narrowing
- Inability to vasodilate or produce vasodilators that could act downstream on smaller vessels
- Possible plaque rupture and thrombosis
What must be in a full chest xray for it to be proper?
- 7 ribs from top of chest to the bottom, all along the mid clavicular line.
- Full picture of the lungs right to the diaphragm
- Trachea and spinous processes aline
- Labelled
- Scapulae out of the way
Kinks in collagen indicate which disease?
Osteogenesis imperfecta
What lipid mediators do mast cells produce in response to activation and long does it take?
Leukotrienes and prostaglandins, 10-30mins
An elevation in which pancrease secreted substance indicates CF?
Immunoreactive trypsin (IRT)
… was the first disease to be routinely tested for at birth and treated as required.
Phenylketonuria (PKU)
What is meant by number needed to treat?
The number of people needed to be treated inorder to prevent the outcome in one person.
At what level does the trachea start?
C6
What is the name of the muscle that connects of the U-rings of the trachea?
Trachealis muscle
What is meant by external validity?
The extent to which the results of trial are relevant to a given clinical situation. A trial must be internally valid to be externally valid but not vice versa.
What are Jawetz’s law (referring to antibiotic antagonism vs synergism)
Bacteriostatic + bacteriostatic = no difference
Bacteriostatic + bacteriocidal = antagonism
Bacteriocidal + bacteriocidal = synergism
What is internal validity?
The extent to which the results are valid for the sample patients being studied. Depends on:
- study design
- data collection
- data analysis
What is the mechanism of reduction in LDL for bile acid sequestrants/resins
Bind to bind acids causing increase in bile secretion > increases the demand for LDL from the blood to make new bile acids in the liver > LDL uptaken via upregulation of cholesterol receptors in hepatocytes
What is the reaction protein in celiac disease
Gliadin from gluten
What are the five requirements of a proper X-ray?
- Standing
- Scapulae out of the way
- Full inspiration
- Posterior to Anterior
- Close to the film
What are some X-linked disease?
Colour blindedness, male pattern baldness, Haemophilia A, Duchenne muscular dystrophy,