Blood Vessel Disorders Flashcards
what is the organisation of blood vessels?
3 layers
- tunica externa w/ external elastic membrane
- tunica media w/ smooth muscle
—- elastic laminae separates
- tunica intima w/ internal elastic membrane
then the lumen
why does the aorta have a lot of elastic fibres?
allows the recoil and flow of large volumes and pressure of blood
why do muscular arteries have more smooth muscle?
allow vasoconstriction and vasodilation
- allows changes of blood flow to pass
describe the structure of capillaries.
single cell layer of endothelial cells
supporting sites = pericytes
which side does oxygenated and deoxygenated blood pass through?
oxygenated - through the aorta, on the left side
deoxygenated - through veins, on the right side
is vascular disease responsible for the highest mortality than any other human disease?
yes
what 4 age-related changes can occur in the arteries? - all come under the term of arteriosclerosis
- tunica intima - fibrous thickening
- tunica media - fibrosis/scarring
- elastic laminae - fragmentation
- dystrophic calcification
why do you get fibrous thickening as an effect of age-related changed in the vascular system?
- exposure
- activates macrophage and monocytes
- lay down extracellular matrix
what is fragmentation of the elastic laminae?
the break down of elastic fibres
- doesn’t recoil as well
why do age-related changes occur in the vascular system?
- long-term exposure to injurious agents, toxins and high blood pressure
define atherosclerosis
- slow, progressive, chronic, degenerative
- intimal disease
- a healing response to endothelial injury on arterial wall
how does ‘atherosclerosis’ occur? (9)
- area has haemodynamic disturbance due to risk factors
- endothelial damage
- permeability increases = leaky
- lipid, macrophages and smooth muscle cell accumulation
- macrophages take up lipids
- accumulate in the wall
==== fatty streak - process progresses
= atheromatous plaque
give 4 genetic and 5 environmental risk factors for atherosclerosis
genetic
- age
- males
- family history
- genetic abnormality
environmental
- hypertension
- smoking
- diabetes
- inflammation
- hyperlipidemia
describe the 3 pathogenesis’ of atherosclerosis
aneurysm and rupture - If the vessel wall weakens
occlusion by thrombus - plaque ruptures, causes thrombosis to occur
critical stenosis from stable plaque = hardened cap and mainly smooth muscle cells = not likely to rupture
- leads to occlusion, hypoxia and angina
what can be the end result with atherosclerosis?
- coronary, cerebral, aorta, mesenteric, lower arteries
in the coronary arteries:
- coronary ischaemic heart disease- angina, arrhythmias, myocardial infarction
carotid/cerebral arteries
- cerebrovascular diseases (stroke)
aorta
- aortic aneurism
mesenteric arteries
- bowel ischaemia
lower extremities
- peripheral vascular disease
what are the morphological features of atherosclerosis
- fatty streak in the intima
- stable plaque = hardened cap and mainly smooth muscle cells = not likely to rupture
- gets larger into critical stenosis
- leads to occlusion, hypoxia and angina
what can be the consequences of atherosclerosis
- evaluated, occlusive intimal-based lesions
AKA PLAQUES
what constitutes a atherosclerotic plaque? (5)
lipids
inflam cells
proliferating smooth muscle cell
extra-cellular matrix
fibrous cap
where does an atherosclerotic plaque protrude into?
into the lumen of the blood vessel
define systemic hypertension
persistently raised arterial blood pressure causing degenerative changes in vessels
why do you need pressure in the blood vessels?
to deliver oxygenated blood
- to pass the resistance in the circulation
describe the difference between systole and diastole
systole
- heart contracts
- raises blood pressure
arterial wall stretches
diastole
- heart relaxs
- lowers blood pressure
- fills back up again with blood
arterial wall recoils
give 2 outcomes of unregulated blood pressure and what they lead to.
hypotension - hypoxia, cell injury/death
hypertension - vessel damage, atherogenesis
give risk factors for systemic hypertension (4)
- increasedsalt intake
- alcohol
- lack of exercise
- increased fat intake
describe potential pathogenesis’ for systemic hypertension (4)
- athersclerosis by endothelial damage
- aortic aneurysm - death
- cardiac hypertrophy - death
- cerebrovascular disease - stroke/dementia
describe the morphological features of systemic hypertension
hyaline arteriolosclerosis - glassy texture, pink stain
- pink material around the vessels with narrow lumen
hyperplastic arteriolosclerosis
- in malignant hypertension
- lots of extracellular matrix
what methods are there for classifying hypertension? (5)
- clinic measurement
- systolic BP = >140
- diastolic BP = >90
- has 3 stages: mild, mod and severe
- home ambulatory blood pressure measurement
- aetiology - primary or secondary
- pathological - benign or malignant
- anatomical - systemic, pulmonary or portal
describe the aetiology classification of hypertension.
primary aka essential hypertension - idiopathic - not a specific cause, very common
- mainly genetic
- vasoconstrictive influences - age
- stress, smoking, obesity, fitness
- decrease in sodium excretion
secondary - specific diseases causing hypertension
- renal disease
- endocrine causes
- cardiovascular
- neurovascular
renal diseases are a secondary factor for hypertension, why?
BP increases because..
- BP drops
- kidney secrete renin
- renin activates angiotensin system
- vasoconstriction
- retains salt and water
= BP increases
what is ‘renal artery stenosis’? how does it lead to hypertension
when the renal arteries are blocked through atherosclerotic process
- kidney perceives decreased blood flow
- renin released
- angiotensin activate
- vasoconstriction
- water and salt retained
- BP increases
how can coarctation lead to increased blood pressure?
if there is coarctation of the aorta
- aorta narrows
- low blood pressure
- leads to renal angiotensin system activation
what neurological process’ lead to hypertension? (4)
sleep apnoea
stress
increased intercranial pressure
psychogenic
what’s the difference between the pathological causes of hypertension from benign and malignant origin?
benign
- asymptomatic
- organ gets damaged gradually
malignant
- rapid hypertension
- if untreated, death
- severe increase of over 180 BP
= renal failure
= retinal haemorrhage
= papillodeama
what is the portal venous system?
a system which drains blood from GIT to the liver
how can hypertension be classified anatomically?
systemic
- pressure in the systemic circulation
pulmonary
- isolated pressure in the pulmonary circulation
portal hypertension
- pressure in the portal venous system
- causes varicosities - dilations
- rupture
- those with liver cirrhosis can die
why is hypertension relevant in dentistry?
increased pain
increased anxieties
- difficult for extractions
- high BP can increase risk for heart attack or stroke
define vasculitis
inflammation of the vessel walls
what is the name for the classification for vasculitis?
Chapel Hill Nomenclature
- depends on the vessel bed and vessel size
what does vasculitis look like?
blue dots in a blood vessel
what is giant cell arteritis?
the most common form of vasculitis
- a chronic granulomatous inflammation affecting large-medium arteries
describe the morphological features (4) of giant cell arteritis and what organs are involved (3)
features:
- intimal thickening
- granulomatous inflammation
- elastic lamina fragmentation
- multinucleate giant cells
organs:
- temporal arteries in the head
- vertebral arteries
- ophthalmic arteries
what complications can there be with ‘giant cell arteritis’?
in the ophthalmic artery - can lead to permanent blindness
in the head - headache, pain on biting = jaw claudication
how would GCA be treated?
with corticosteroids - anti-inflame drugs
define ‘aneurysm’
a localised, permanent, abnormal dilation of a blood vessel
how are ‘aneurysms’ classified
aetiology - are berries dark milk or fake smooth milk? (7)
shape
- saccular - bulges out on one side
- fusiform - bulges out both sides
- dissecting - blood between intima and media
aetiology
- atheroslerotic
- berries
- dissecting
- microaneurysms
- false
- syphlitic
- mycotic
what is a berry aneurysm? what does the rupture cause?
a small, saccular lesion developing in the Circle of Willis in the brain at points of bifurcation
causes subarachnoid haemorrhage
what are micro and syphilitic aneurysms also known as? where do they occur and what do they cause?
aka Charcot-Bouchard aneurysms
- occur in intracerebral capillaries
- cause intracerebral haemmorhage - stroke
how can retinal microaneurysms arise? what is their pathogenesis
from diabetes causing diabetic retinopathy
what are mycotic aneurysms? how does it occur in the tunica media?
weakening of arterial wall due to bacterial/fungal infection
- enter tunica media from the vasa vasorum
what aneurysm come under Charcot-Bouchard aneurysms
micro and syphilitic
what is the most common infection leading to mycotic aneurysms?
subacute bacterial endocarditis
what is a false aneurysm?
a blood filled space around a vessel usually after traumatic rupture or perforating injury
describe a dissecting aneurysm, with symptoms and common location.
a tear in the wall, so blood tracks between intima and media layer
symptoms - tearing pain in chest radiating to upper left shoulder
common location - thoracic aorta
where is the most common location for an aneurysm secondary to aorta
abdominal aortic region
what is the main risk factor for rupture
the bigger the size, the more chance of rupture
compare the pathology and complications of different aneurysms
cause haemorrhage or ischamia from thromboembolism
what can be the result of ‘arterial occlusion’? (3)
embolism, ischaemia, infarction
what is ‘chronic peripheral arterial occlusive disease’? state the pathological consequences
narrowed arteries leading to reduced blood flow to limbs
can lead to critical limb ischaemia
what are the 3 different types of blood vessel tumours?
Haemangioma
- benign
- head, neck, thorax
Kaposi Sarcoma
- intermediate grade, neither benign or malignant
- results from infection
: AIDS or HHV8 - Human Herpesvirus 8
Angiosarcoma
- malignant
- associated with: lymphoedema, radiation
what are the 6 P’s on acute ischaemia
Pale
Painful
Paralysed
Paraesthetic - tingly
Perishing Cold
Pulseless
