Cardiovascular Pathology Flashcards
important
Be familiar with arteries, vessels, and lymphatic system and things that could go wrong
What is the best way to distinguish between an artery and a vein?
Wall thickness is the best way to differentiate veins and arteries
What structures are found in all blood vessel types?
Endothelial cells
Smooth muscle cells
Extracellular matrix
What can happen if there are changes in wall thickness?
Changes in wall thickness can lead to atherosclerosis and hypertension
What are the layers of the blood vessels?
Tunica intima (inside)
Tunica media (Most closely packed fibers)
Tunica adventitia (most external)
What are the components of
Intima consists of a single layer of endothelial cells
Basement membrane
thin layer of extracellular matrix
What does relative size of tunica media and adventitia tell us?
If media is bigger than adventitia there is lots of muscle therefore it is an artery. Vice versa for vein
What can go wrong with blood vessels?
Blockage (preceded by narrowing)
Rupture (Preceded by weakening)
What does turbulent blood flow result in?
Turbulent blood flow can result in inside of blood vessel activating the coagulation cascade (can be because of an injury)
What happens in response to vascular wall injury?
Adhesion molecules become activated (endothelial activation) and attach to the platelets
Cytokines are released to attract repair
Vasoactive compounds are released (constriction factors mostly but some dilation to create a balance to prevent blood from shutting off completely)
Smooth mulscles develop, grow and remodel
Intimal thickening takes place
Increased expression of procoagulants, and proinflammatory markers.
Altered expression of chemokines, cytokines, and growth factors.
What factors can induce vascular wall injury?
Turbulent flow
Hypertension
Cytokines
COmplement
Bacterial products
Lipid products
Advanced glycation end products
Hypoxia, acidosis
Viruses
Cigarette smoke
What types of vascular pathology are there?
Vascular patholgoy is either blockage or rupture
How does vascular wall thickening?
Endothelium
Recruitment of smooth muscle cells or smooth muscle precursor cells to the intima
Smooth muscle cell mitosis
Elaboration of extracellular matrix
What are the blood pressure categories?
Normal: <120; <80 Elevated: 120 - 129; <80 High blood pressure stage 1: 130 - 139; 80 - 89 HBP stage 2: 140 or higher; 90 or higher Hypertensive crisis: >180;>120
What is blood pressure?
CO x TPR
What is CO?
Blood volume (Sodium, mineralocorticoids, ANP)
HR and contractility
What factors affect TPR?
Humoral factors: Contrictors and dilators
Neural factors: alpha and beta adrenergic
Local factors: Autoregulation, pH, and hypoxia
What does MI do to heart contractility?
MI leads to reduced contractility of the heart muscles it affects.
What is renin and what does it do?
Renin is produced by the kidneys.
Renin converts ANGogen to ANG1 which is converted to ANG2 and increases vascular smooth muscle tone.
ACE inhibitors increase BP
How many people are hypertensive?
~29% of people were hypertensive
Which demographic has lower threshold for hypertension?
Threshold is lower in diabetic patients. Hypertension consequences are exacerbated by diabetes
What causes hypertensive vascular disease?
Idiopathic or primary 90 - 95%
Secondary 5 - 10%
What does hypertensive vascular disease result in?
Increased risk of atherosclerosis
Cardiac hypertrophy
Heart failure
Aortic dissection
Multi-infarct dimentia
Renal failure
What demographic has the most severe and prevalent incidence of hypertensive vascular disease?
African-Americans
What happens if hypertension is undiagnosed?
If left untreated, 50%of patients may die of ischaemic heart disease
5% of patients die of rapidly rising blood pressure
What percentage of strokes, heart disease, and all cause mortality is due to undiagnosed hypertension?
62% of strokes
49% of ischaemic heart disease cases
13% of all-cause mortality worldwide
What is the outcome of reduction of diastolic BP?
Lowering diastolic BP by 5mmHg results in 34% reduction in stroke risk
What is arteriolosclerosis?
Hardening of the arteries. (Artery wall thickening and loss of elasticity)
What are the patterns of arteriolosclerosis?
Patterns:
Arteriolosclerosis
Small arteries and arterioles
May cause downstream ischemic injury
Monckeberg medial sclerosis
Calcification of the wall of arteries
Atherosclerosis
The most important
What is the outcome of atherosclerotic plaques in the blood vessels?
If stable: Blood moving fast results in slowing down at the Thickening leading to potential clotting of the blood vessel.
If unstable: Ruptures and fat can enter blood stream and cause emboli to form.
What determines likelihood of atherosclerosis?
Likelihood determined by:
Acquired (cholesterol, smoking, HTN)
Inherited (LDL, receptor gene mutations)
What are the risk factors for atherosclerosis?
Genetic: rarely mendelian, often polygenic (familial inflammatory conditions)
Age: 40 - 60
Gender: Males and females post menopause
What causes cardiomegaly?
Hypertrophy (increased weight or thickness)
Dilation (chamber size larger)
What causes cardiomegaly?
Could be due to compensatory changes as a result of:
Heart disease
Volume/pressure overload
What is the contractile unit called in the heart?
Myocytes: Contraction unit is called a sarcomere
What is the most common form of arrhytmia?
Atrial fibrillation
What is a potential outcome of atrial fibrillation?
It can lead to a blood clot to form which can become a thromboembolism
What are the important coronary arteries to know?
Left and right
Left: LAD and LCX
Right
What kind of metabolism do cardiomyocytes need and what happens if there is an infarction?
Energy from oxidative phosphorylation and if no oxygen they can die from hypoxia
