Cardiology Flashcards
(438 cards)
What is the relationship between aspirin and NSAIDS?
NSAIDS interferes with with asprin
Both NSAIDs and aspirin inhibit the activity of COX. However, NSAIDs primarily block COX-1 and COX-2 enzymes, which are involved in inflammation and pain. On the other hand, aspirin inhibits irreversibly COX-1, which plays a role in blood clotting. When NSAIDs and aspirin are taken together, NSAIDs might interfere with aspirin’s binding to COX-1, reducing its effectiveness in preventing blood clotting.
What forms the cardiac plexus
Sympathetic fibers from T1-T5
Parasympathetic fibers from vagus nerve
Visceral sensory fibers
What is the normal pulmonary artery pressure
24/10 mmHg/mmHg
What is angina
Chest pain
What is the normal pH of blood
7.35-7.45
What regulates vasodilation
RAAS NOT the parasympathetic ns
What does thrombopoetin do
Make more platelets
What is the effect of cAMP on platelet aggregation
Inhibits it
Explain the formation of prostacyclins and thromboxane A2 and link this to why asprin is inhibited by NSAIDS
Arachidonic acid is converted via cox1 and cox2 to prostaglandins. Then the prostaglandins either go to platelets and form TxA2 to promote coagulation OR go to the endothelium to form prostacyclin which is anticoagulant.
Asprin and NSAIDS both bind to cox1 (nsaids also bind to cox2) so they compete for that site > the action of asprin is reduced
Explain the functions of cAMP
Vasodilation
Increase HR
BRONCHODILATION
How do you treat sickle cell disease
Hydroxyurea > makes cells rounder and increases synthesis of foetal hb
what is now thought to cause sickle cell crisis
HbS causes endothelial damage which leads to platelet aggregation in capillaries in BONE and occlusion
CO formula
HRxSV
CO formula
HRxSV
BP formula
COxTPR
PP formula
pulse pressure
Systolic pressure - diastolic pressure
MAP formula
Diastolic pressure + 1/3PP
Define preload
The initial stretching of the heart before contraction
Define afterload
The pressure against which the heart has to contact to eject blood
explain different mechanisms for blood pressure control and secreted or circulating factors which influence blood pressure
1) myogenic autoregulation
Vasoconstrictors
- endothelin 1
- decreased BP
- angiotensin 2
- ADH
- adrenaline
Vasodilators
- low O2
- high CO2
- high adenosine from ATP breakdown
- increased K+
- increased H+
- increased metabolism (tissue breakdown products)
-NO
- prostacyclin
- ANP
- adrenaline vasodilates blood in muscles
baroreceptors and chemoreceptors in carotid sinus/carotid and aortic arch
medulla
sympathetic and parasympathetic system
RAAS
hypothalamus –> regulates skin BP in response to temperature
what are the layers of the heart?
pericardium
epicardium
myocardium
endocardium
how long is the delay at the AV node
0.1 s
where do you measure the central venous pressure?
in the right atrium
explain the heart sounds
S1 - closure of mitral and right av valves
S2 - closure of aortic and pulmonary valve
S3 - associated with the rapid filling of the ventricle during the early phase of diastole, usually caused by passive flow from the atria to the ventricles. It happens when the ventricles are overly compliant, allowing more blood to enter during the rapid filling phase.
When the atria contract to push additional blood into the ventricle during its filling phase (diastole), this added volume can create turbulent flow or vibrations, which can manifest as the S3 sound.
S4 - occurs just before the first heart sound (S1) and is associated with atrial contraction. It’s often heard when the atria contract forcefully to push blood into a stiff or non-compliant ventricle.